Using Historical NASA Cost and Schedule Growth to Set Future Program and Project Reserve Guidelines

Abstract: [Seed reference from approved prospectus.]


Historical mass, power, schedule, and cost growth for NASA science instruments


Historical mass, power, schedule, and cost growth for NASA spacecraft


The effect of policy changes on NASA science mission cost and schedule growth

R. Bitten
C. Hunt
D. Emmons
R. Kellogg
E. Mahr


Schedule matters: Understanding the relationship between schedule delays and costs on overruns


Controlling Cost Growth of NASA Earth and Space Science Missions


Research Note: Public and Private Managers' Perceptions of Red Tape


The Impact of Red Tape on Governmental Performance: An Empirical Analysis

Journal of Public Administration Research and Theory


Administrative Exclusion: Organizations and the Hidden Costs of Welfare Claiming


Green Tape: A Theory of Effective Organizational Rules


A New Measure of Red Tape: Introducing the Three-Item Red Tape (TIRT) Scale


Bureaucratic Competence and Procurement Outcomes

F. Decarolis
L. M. Giuffrida
E. Iossa
V. Mollisi
G. Spagnolo


Five things you should know about cost overrun

B. Flyvbjerg
A. Ansar
A. Budzier
S. L. Buhl
C. C. Cantarelli


Cost Overruns on Infrastructure Projects: Patterns, Causes, and Cures


Cost Overruns in Large-scale Transportation Infrastructure Projects: Explanations and Their Theoretical Embeddedness

European Journal of Transport and Infrastructure Research


The Maddison Project: Historical GDP estimates worldwide

Journal of World-Historical Information / Maddison Project Database


Railroad Impact in Backward Economies: Spain, 1850-1913


Institutions, Institutional Change and Economic Performance


Survey of cost models for space telescopes


Effectiveness of Firm-Fixed Price Spacecraft Contracts to Curb Cost Growth


Difference-in-Differences with Variation in Treatment Timing


Difference-in-Differences with multiple time periods


Difference-in-Differences Estimators of Intertemporal Treatment Effects


On the Use of Two-Way Fixed Effects Regression Models for Causal Inference with Panel Data


The Roles of Management Control: Lessons from the Apollo Program


The World Economy: A Millennial Perspective

Abstract: [Anchor/adjacent reference surfaced by Hall-of-Shoulders dossier brain.]


The Mechanisms of Governance


The Economics of Organization: The Transaction Cost Approach


Difference-in-differences with variation in treatment timing (journal version)


Curbing Optimism Bias and Strategic Misrepresentation in Planning: Reference Class Forecasting in Practice


Governing the Commons: The Evolution of Institutions for Collective Action


Space, the Final Economic Frontier


Rival Explanations (Encyclopedia of Case Study Research)

SAGE Encyclopedia of Case Study Research


Houston...We Have a Cost Problem: A Financial Analysis of NASA Contractors

Kevin T. Rich
Finnbar Cocoman
Kate Dugan
Andrea Golvach
Tyler Tyler
Hunter Sandidge

54th International Conference on Environmental Systems

Abstract:
A recent Government Accountability Office (GAO) report
highlighted that 15 projects in the development phase of
NASA’s acquisition process were responsible for $12 billion
in cost overruns and cumulative schedule delays of 28
years. One possible culprit involves outside contractors,
given they ultimately receive a significant piece of the
NASA budget. Additionally, recent high-profile endeavors
such as the Artemis program have faced scrutiny over their
procurement strategies causing increases in costs and
scheduling delays. Understanding patterns in historical
data can provide valuable insights into cost management
practices. In this study, we perform a comprehensive
analysis of NASA contractors in terms of who is receiving
contracts, what they are spending on, and how the contracts
are structured. We use prime contractor data from 2008 to
2024 and find evidence that fixed price contract


Examining of Project Cost Overrun in Project Management: A Case Study of the Road Development Agency in Lusaka

International Journal of Advanced Multidisciplinary Research and Studies

Abstract: This study investigated the persistent problem of cost overruns in road construction projects managed by the Road Development Agency (RDA) in Lusaka. Recent evidence showed that 78% of projects had exceeded their budgets by an average of 52%, with flagship projects such as the Lusaka-Ndola dual carriageway, Kafue Road expansion, and the Lusaka Decongestion Project recording significant financial escalations. These overruns not only consumed a large share of Zambia’s infrastructure budget but also resulted in delays, reduced quality, and premature defects, raising concerns about long-term sustainability. Guided by Agency Theory, the study examined the causes and consequences of these overruns, focusing on systemic weaknesses in planning, procurement, financial management, and stakeholder relations. A single-case study design was applied, drawing data from 60 respondents, including enginee


Dealing with construction cost overruns using data mining

Abstract:
One of the main aims of any construction client is to procure a project within the limits of a predefined budget.
\nHowever, most construction projects routinely overrun their cost estimates. Existing theories on construction
\ncost overrun suggest a number of causes ranging from technical difficulties, optimism bias, managerial incompetence
\nand strategic misrepresentation. However, much of the budgetary decision-making process in the early
\nstages of a project is carried out in an environment of high uncertainty with little available information for accurate
\nestimation. Using non-parametric bootstrapping and ensemble modelling in artificial neural networks, final
\nproject cost-forecasting models were developed with 1600 completed projects. This helped to extract information
\nembedded in data on completed construction projects, in an attempt to address


FORECASTING AND FINANCIAL PREDICTABILITY IN COMPLEX INFRASTRUCTURE AND ENERGY PROJECTS

Abstract: Complex infrastructure and energy projects are highly exposed to cost overruns, delays, contractual changes, macroeconomic variations, and scope revisions. In this context, this article analyzes how financial forecasting can enhance economic predictability and improve executive decision-making in capital-intensive projects. The research is qualitative and theoretical-analytical in nature, developed through a narrative literature review. The analysis articulates contributions on cost overrun, optimism bias, strategic misrepresentation, reference class forecasting, project controls, and the finance function. The findings indicate that forecasting should not be treated as a simple spreadsheet update or reporting routine, but as a mechanism for continuously revising the assumptions that support the project’s economic trajectory. When integrated with risk analysis, estimate at completion, con


The Impact of Strategic Procurement on Cost Overruns and Delays in Petroleum Exploration and Production Projects

African Journal of Procurement, Logistics & Supply Chain Management

Abstract:
Cost overruns and project delays persist as significant challenges in petroleum exploration and production (E&P) projects, frequently resulting in reduced profitability, strained stakeholder relationships, and missed strategic objectives. This study investigates the impact of strategic procurement practices on mitigating cost and schedule risks in petroleum projects. Using a dataset of 120 projects, the study employs descriptive statistics, correlation analysis, and multiple regression modelling to evaluate the role of supplier relationship management (SRM), early supplier involvement, contract alignment, supplier qualification, and digital enablement in influencing project performance.
The findings reveal that SRM and early supplier involvement significantly reduce cost overruns, while contract alignment demonstrates a marginal yet negative effect on cost growth. In terms of schedu


The Theoretical Foundation of Strategic Procurement: Mitigating Cost Overruns and Delays in Petroleum Exploration and Production Projects

Abstract:
Petroleum exploration and production (E&P) projects are high-stakes megaprojects that are notoriously susceptible to cost overruns and delays. This paper posits that a fundamental shift from a traditional, transactional procurement model to a strategic approach can serve as a powerful mechanism for mitigating these systemic issues. The study develops a conceptual framework by synthesising four key theoretical perspectives. Transaction Cost Economics (TCE) explains how strategic procurement's structured processes reduce the administrative and operational costs associated with complex transactions.
Agency Theory addresses the principal-agent problem, demonstrating that robust Supplier Relationship Management (SRM) can align interests and mitigate opportunistic behaviour, a primary driver of project failure. The Resource-Based View (RBV) re-frames procurement as a source of sustainable


Modified Fuzzy Group Decision-Making Approach to Cost Overrun Risk Assessment of Power Plant Projects

Muhammad Saiful Islam
Madhav Nepal
Martin Skitmore

Journal of Construction Engineering and Management

Abstract: Cost overrun risk assessment in the preliminary stages of a power plant project is laden with subjectivity, uncertainty, imprecision, and the vagueness of expert judgment. Current fuzzy approaches to risk assessment in such projects specifically require improvements in the reliability and aggregation process of experts’ judgments as well as the incorporation of project phase–based risk assessment to comprehend the sources of the risks and their corresponding effects on cost overruns. In response, this study proposes a modified fuzzy group decision-making approach (FGDMA) and assesses cost overrun risks considering different project phases [(1) design and procurement, and (2) construction and commissioning] of the power plant projects of varying types, sizes/capacities, and contracts. The proposed methodology is applied to 10 different project scenarios to better understand the context of


Optimism Bias Evaluation and Decision-Making Risk Forecast on Bridge Project Cost Based on Reference Class Forecasting: Evidence from China

Hui-min Liu
Canhui Jiang
Y. Liu
M. Hertogh
Xueguang Lyu

Abstract: The high uncertainty of megaproject results in increasing complexity in the decision-making and ultimately leads to different degrees of cost overrun and project delays. One of the critical reasons for cost overrun and delay is the optimism bias of decision makers. Although the previous literature has analyzed the cost overrun distribution of bridges, roads and other infrastructure projects, there is still a lack of research on how to make more reasonable decisions according to the cost overrun risk and cost-benefit theory by considering the expectation of cost overrun. Therefore, this paper firstly measures optimism bias by conducting the field research and interviews regarding over 30 long bridges in China. On the basis of the optimism bias measure, a decision-making risk model of bridge projects with the expectation of cost overrun has been built. Then the paper takes Hangzhou Bay Bri


Heritage and Advanced Technology Systems Engineering Lessons Learned from NASA Deep Space Missions

Bryan Barley
Allen S. Bacskay
Marilyn Newhouse

Abstract: In the design and development of complex spacecraft missions, project teams frequently assume the use of advanced technology systems or heritage systems to enable a mission or reduce the overall mission risk and cost. As projects proceed through the development life cycle, increasingly detailed knowledge of the advanced and heritage systems within the spacecraft and mission environment identifies unanticipated technical issues. Resolving these issues often results in cost overruns and schedule impacts. The National Aeronautics and Space Administration (NASA) Discovery & New Frontiers (D&NF) Program Office at Marshall Space Flight Center (MSFC) recently studied cost overruns and schedule delays for 5 missions. The goal was to identify the underlying causes for the overruns and delays, and to develop practical mitigations to assist the D&NF projects in identifying potential ris


Modeling construction cost overrun risks at the FEED stage for mining projects using PLS-SEM

Maan A. Shafaay
Fahad K. Alqahtani
Abdullah Alsharef
Gongfan Chen

Journal of Asian Architecture and Building Engineering

Abstract: ABSTRACT The mining industry consistently faces significant cost overruns during construction, rooted in the Front-End Engineering Design (FEED) stage, with overruns reported between 25% and 37%, underscoring the need to investigate early-stage risk factors. This study utilizes Partial Least Squares Structural Equation Modeling (PLS-SEM) and has identified 10 critical risk factors that significantly influence cost overruns in mining projects. These critical factors include impractical project schedules, inadequate project feasibility studies, client pressure to minimize the initial capital requirements, inaccurate cost estimations, increase of inflation rates, increase of official exchange rate, poorly understood geological and geotechnical aspects of a deposit, permit acquisition and approval delay, supply chain delays, and Impact on local communities and infrastructure. The robust anal


Quantitative Risk Assessment and Management of National Defense Acquisition with a Game-Theoretic Security Risk Meter Tool

International Journal of Computer Theory and Engineering

Abstract: —Driven by the ever-increasing cost and complexity of Department of Defense (DoD) defensive weapons acquisitions and requirements as well as contracting and financial management challenges, risk assessment and management are an undeniably essential component of the defense acquisition process. Identifying and managing the vulnerabilities and threats that affect defense acquisition scientifically is critical to an efficient and cost-effective acquisition process. Failure to identify and manage these sources of risk has very real consequences ranging from schedule delays and cost overruns to project cancellation not only for U.S. but all modern nations. The Defense Acquisition Risk Meter (DARM) innovatively provides an indispensable tool for program managers, politicians and high-level decision makers, and tax payers who shoulder the burden. Using game theory and statistically-driven metho


The Effect of Strategic Procurement Management on Cost Overruns and Schedule Delays in Petroleum Engineering Projects in Ghana

Project Management and Scientific Journal

Abstract:
Petroleum engineering projects are highly capital-intensive and complex undertakings that frequently experience cost overruns and schedule delays, particularly in developing economies such as Ghana. This study examined the effect of strategic procurement management on cost overruns and schedule delays in petroleum engineering projects in Ghana. The study was guided by the need to understand how procurement-related practices influence project performance outcomes in the oil and gas sector. A quantitative explanatory research design was adopted, using a cross-sectional survey approach. Primary data were collected from 142 professionals involved in petroleum engineering projects, including procurement managers, engineers, contract administrators, and supply chain specialists. Data were analysed using descriptive statistics, Pearson correlation, and multiple regression analysis.
The finding


Optimising Procurement Strategies for Cost Efficiency and Risk Mitigation in Petroleum Engineering Projects: The Study of Offshore Drilling Operations

Abstract:
Procurement plays a pivotal role in shaping the performance of offshore petroleum engineering projects, where cost overruns, schedule delays, and high-risk exposures are frequent challenges. This research examines how procurement strategies can be optimised to improve cost efficiency and mitigate risks in offshore drilling operations. Using a project dataset covering total cost of ownership (TCO), schedule delays, and risk scores, the study evaluates the effectiveness of contract types, sourcing strategies, and digital maturity in influencing project outcomes.
The results reveal that framework and alliance contracts, particularly when combined with dual-sourcing strategies, achieve superior cost efficiency and lower risk scores compared to lump-sum and single-sourcing arrangements. However, schedule delays were found to be largely unaffected by sourcing strategies, averaging around 14–1


Reducing Cost Overrun in Public Housing Projects: A Simplified Reference Class Forecast for Small Island Developing States

Aaron Chadee
Hector Martin
Sihara Gallage
Upaka Rathnayake

Abstract: Inaccuracies in cost estimation on construction projects is a contested topic in praxis. Among the leading explanations for cost overrun (CO), factors accounting for large variances in actual cost are shown to have psychological or political roots. The context of public sector social housing projects (PSSHPs) in Small Island Developing States (SIDS) is positioned with similar CO challenges. This study is the fifth phase of a series of research projects on the vulnerability of PSSHPs to COs, and the need to de-risk cost estimates. The aim of this study is to present a simple and practical application of Reference Class Forecasting (RCF), a promising solution utilizing an “outside view” approach, as an effective control to reduce the variance of forecasted cost inaccuracies. Using a sample set of 82 housing projects, a reference class of 23 projects was selected based on properties such as


Oil and Gas Projects in Sultanate of Oman: Construction Schedule and Cost Overrun

Abstract: Oil and Gas (O&G) industry is the primary source of the gross national income in gulf area. This industry is facing construction related issues that lead to cost overrun and delay in construction schedule of the construction related tasks. During COVID 19 pandemic, Sultanate of Oman O&G construction projects are facing many problems due to many factors. As a result and use these factors, about 70% of the major projects suffer from schedule slip and increasing costs. This has direct impact on the government budget with about 15% of GDP.  This research is discussing the main factors and its root causes that have direct impact on construction cost and schedule for O&G projects. This is has been done based on the literature and the conducted survey.


Readings in program control

Francis T. Hoban
William M. Lawbaugh
Edward J. Hoffman

NASA STI Repository (National Aeronautics and Space Administration)

Abstract: Under the heading of Program Control, a number of related topics are discussed: cost estimating methods; planning and scheduling; cost overruns in the defense industry; the history of estimating; the advantages of cost plus award fee contracts; and how program control techniques led to the success of a NASA development project.


From Delay to Delivery: Tackling Time and Cost Risks in Hydropower Projects

International Journal for Research in Applied Science and Engineering Technology

Abstract:
This study examines the persistent global problem of time and cost overruns in hydropower projects, with emphasis on
India. Although hydropower is central to renewable energy strategies and grid stability, project implementation is often hindered
by major delays and budget escalations. Since 2000, international data indicate average cost overruns above 30% and schedule
delays over 18% (Ansar et al., 2014). The research identifies the root causes of these overruns, evaluates their prevalence in
India, reviews case studies, compares national and global trends, and analyses factors such as regulatory complexity, geological
challenges, technological integration, and managerial practices. It also highlights best practices to improve project outcomes.
Both technical and non-technical factors drive overruns. Technical contributors include complex engineering demands,
construction inefficiencies


Real-Time Delivery Control for ICT Programs: A Telemetry-Driven Framework for Cost, Schedule, and Risk Optimization in Enterprise Project Execution

Journal of Information Systems Engineering & Management

Abstract:
High schedule overruns, cost deviations, and scope failure rates persist in information and communication technology (ICT) programs of business enterprises, with industry analyses showing that fewer than one-third of large-scale software projects are on time and on budget. These results are, in large part, avoidable because conventional project management paradigms are structurally limited: their reliance on periodic milestone reporting, fixed dashboards, and lagging performance indicators, which, by their very nature, are incapable of detecting meaningful sources of delivery risk in real time.
This paper presents the Telemetry-Driven Delivery Control Framework (TDCF), a broad, scaled-up approach to achieving sustainable visibility, anticipatory risk recognition, and responsive control across numerous complex enterprise ICT programs. The TDCF defines a five-layer architecture that inclu


Reference Class Forecasting and Its Application to Fusion Power Plant Cost Estimates

Abstract: Developments in fusion energy technology and the aspiration to build and run commercial fusion energy power plants have seen the commencement of numerous publicly and privately funded projects in recent years. Megaprojects, like fusion power plants, by their very nature are inherently complex and risky, therefore, providing a robust cost estimate in the early stages is challenging. In the fusion sector, this is amplified by the fact that very little data exist on which to base an estimate due to the novel nature of the materials and technologies involved. A common phenomenon during the estimating phase of a new project is the concept of optimism bias (OB), where underestimation of time, cost, and risk can cause impacts on the baseline cost and schedule, leading to significant over-runs during the project lifetime. Reference class forecasting (RCF) is a method used to mitigate against the


Ideology and Performance in Public Organizations

Abstract: We combine personnel records of the United States federal bureaucracy from 1997 to 2019 with administrative voter registration data to study how ideological alignment between politicians and bureaucrats affects turnover and performance. We document significant partisan cycles and turnover among political appointees. By contrast, we find no political cycles in the civil service. At any point in time, a sizable share of bureaucrats is ideologically misaligned with their political leaders. We study the performance implications of this misalignment for the case of procurement officers. Exploiting presidential transitions as a source of “within‐bureaucrat” variation in political alignment, we find that procurement contracts overseen by misaligned officers exhibit greater cost overruns and delays. We provide evidence consistent with a general “morale effect,” whereby misaligned bureaucrats are


Reducing risks in megaprojects: The potential of reference class forecasting

Abstract: Large infrastructure projects often suffer from cost and schedule overruns, mainly due to optimism bias and strategic misrepresentation. Reference class forecasting (RCF) offers a potential remedy. This study presents a comprehensive analysis of the RCF literature with the aim of providing practitioners with key insights and identifying areas for future research. Through a review of 41 selected papers, the paper shows that the effectiveness of RCF is mainly applicable to large-scale projects and depends on the definition of the reference class. The paper calls for the development of an empirically based framework for reference class formation and urges the exploration of RCF's adaptability across industries, challenging the current one-size-fits-all approach. Theoretically, the paper critically assesses the current applications of RCF, while practically it outlines directions for future


Governing Large Projects: A Three-Stage Process to Get It Right

Dan Lovallo
Matteo Cristofaro
Bent Flyvbjerg

Abstract: Private and public megaprojects, whether new plant facilities, IT systems, skyscrapers, airports, railways, roads, or the Olympics, are frequently associated with dramatic cost and schedule overruns. The root causes are behavioral biases – such as optimism and deliberate deception – accompanied by principal-agent issues and a lack of project-related skills. Through a three-stage process – i.e., Forecasting, Organizing, and Executing (FOX) – we organize and offer solutions to mitigate the cognitive biases and agency issues planners and policymakers face in large projects. Following the three-stage FOX process and building on Behavioral Decision Theory (BDT), we first review evidence for the accuracy of Reference Class Forecasting (RCF), which considers comparable past projects to forecast a current, planned project. We provide evidence for RCF performance and recent methodological extensi


The Influence of Optimism Bias on Time and Cost on Construction Projects

Aaron Anil Chadee
Salisha R. Hernandez
Héctor Martín

Abstract: The unresolved scholarly debate to curtail cost and time performances in projects has led to alternate solutions, departing from the dominant technical school of thought to include concepts from behavioural sciences. In this paper, we consider the psychological effect, namely optimism bias, as one of the root causes for delays in cost overruns on projects. The research objectives were to determine the level of bias among project participants, rank time and cost overrun causes according to the participants’ bias score and establish a mitigation strategy to curb potential delays and cost overrun impacts based on the bias scores obtained. A literature survey was conducted to determine causal factors contributing to delays and cost overruns linked to optimism bias. Through a pilot survey of three semi-structured interviews, eighty factors obtained from the literature survey were reduced to 2


THE COST PERFORMANCE AND CAUSES OF OVERRUNS IN INFRASTRUCTURE DEVELOPMENT PROJECTS IN ASIA

Jelena M. Živković
Abdul‐Majeed Mahamadu
Jiayuan Wang
Patrick X.W. Zou
Ruoyu Zhong

Journal of Civil Engineering and Management

Abstract: Infrastructure plays a major role in the economic development of countries, especially in Asia which has experienced tremendous growth in recent years. The procurement of infrastructure continues to be characterized by cost overruns resulting in significant academic interest and theoretical propositions on the influential factors. This study contributes to this issue through adoption of pragmatic research methodology involving deterministic statistical analysis of real project data from reports as well as a qualitative analysis of these reports to unearth underlying issues from a thematic analysis. Furthermore, the study design takes a multi-country view towards establishing the role of contextual and geographical influences on cost overrun. An evaluation of 102 major infrastructure projects was performed covering railways, roadways and energy sectors in different regions in Asia. Findin


XAI-enabled probabilistic pipeline for predicting delay and cost overrun risk in construction

Engineering Construction and Architectural Management

Abstract:
 We develop an uncertainty-aware, Explainable Artificial Intelligence (XAI)-enabled probabilistic framework to predict and explain delay-driven cost risk in construction, accounting for time-varying exposures driven by supply reliability, regulatory cadence and labor stability.

 Using data from 46 US high-rise projects, we estimate a hierarchical competing-risks Weibull survival model with time-varying covariates and project-level random effects via HMC/NUTS. We link posterior predictive delay exceedance to a stochastic cost overrun layer and integrate XAI through posterior-aware SHAP (global and local importances with 95% credible bands), interaction effects, and counterfactual recourse. Decision-curve analysis quantifies net benefit across operational trigger thresholds.

 Relative to non-XAI baselines, the approach improves time-to-event discrimination and calibration (e


How to solve big problems: bespoke versus platform strategies

Abstract: Abstract How should government and business leaders solve big problems? Ought policy responses to occur in bold leaps or multitudinous methodical moves? Here we show that one-off major projects, with a high level of bespoke content, are prone systematically to poorer outcomes than projects built with a repeatable platform strategy. Repeatable projects are cheaper, faster, and scale in volume and variety at much lower risk of failure. We arrive at these conclusions using comparative evidence—NASA vs SpaceX—on cost, speed-to-market and schedule, and scalability outcomes of their respective space missions. Our reference class dataset consists of 203 space missions spanning 1963–2021, of which 181 missions belong to NASA and 22 belong to SpaceX. We find that SpaceX’s platform strategy was 10X cheaper and 2X faster than NASA’s bespoke strategy. Moreover, SpaceX’s platform strategy was less ri


Analysis of Cost Overrun and Schedule Delays of Infrastructure Projects in Low Income Economies: Case Studies in Ethiopia

Solomon Melaku Belay
S. Tilahun
M. Yehualaw
J. Matos
Hélder Sousa
Endalew Temesgen Workneh

Abstract: Today, several developing countries struggle to improve the cost and time performances of major infrastructure works due to various reasons. Cost overrun and delay are one of the major challenges being faced by the construction and infrastructure sector. Hence, the aim of this study is to explore the extent of cost overrun and schedule delays in building and road infrastructure projects across the Ethiopian construction industry. Primary data were collected through a structured questionnaire survey to evaluate the potential risks leading to those challenges. Various data analysis tools were employed, to investigate the critical causes of cost overrun and delays in infrastructure projects. The findings reveal that the minimum cost overrun for building construction projects is found to be 2%, whereas the maximum and average cost overruns are 248% and 35%, respectively. For road infrastruct


Risk and Uncertainty in the Cost Contingency of Transport Projects: Accommodating Bias or Heuristics, or Both?

P. E. Love
Lavagnon A. Ika
J. Matthews
Weili Fang

IEEE transactions on engineering management

Abstract: Transport projects are regularly subjected to cost misperformance. The contingency set aside to cover any increases in cost due to risk and uncertainty issues is often insufficient. We review approaches that have been used to estimate a cost contingency. We show that some approaches such as reference class forecasting, which underpins the planning fallacy theory, take a biased view to formulate a contingency. Indeed, there is a perception that the risks and uncertainties that form the parts of a cost contingency cannot be accurately assessed using heuristics. The absence of an overarching theory to support the use of heuristics has resulted in them often being downplayed in a project's investment decision-making process. This article fills this void and provides the theoretical backdrop to support the use of heuristics to formulate a cost contingency. We make a clarion call to reconcile


Applying MBSE 2.0 with Intent Aforethought

Abstract:
 The objective of this paper is to provide guidance to the practitioner initiating a model-based systems engineering (MBSE) approach to a system design process. The principles discussed here are applicable irrespective of the domain subject matter of the design and reflect experience drawn from across a range of domains from military-aerospace to property and casualty insurance process to healthcare delivery and subsea oil and gas operations.
 It is well recognized that the oil and gas industry has a substantial problem with cost overruns and schedule delays. Citing a 2014 Ernst and Young study of 365 projects with a proposed capital investment of above US$1b that reviewed project performance in the oil and gas industry They found that 64% are facing cost overruns and 73% are reporting schedule delays. [EYGM, 2014] Matthew Hause and Steve Ashfield tied the solution to much of the overru


Cost overrun and time delay of construction project in Indonesia

Abstract: The success factors of project was completing the project without time delay and cost overrun. Time delay and cost overrun were arised due to uncertainty activity during the life cycle project. This may lead the problems to the project. The research aim was analysing cost overrun and time delay in construction project. Data were collected using questionnaire to 36 respondent. 15 factors have been identified in this research i.e land acquisition delay, location of site, support or protest from the local for the project, changes in design specifications, rework, subcontractors and vendors performance, delay in works approval, inaccurate budgeting and resource planning, price escalation of materials, rules and regulations of the government, owners additional required, inflation, payment delay, weak cash flow and bad weather. The result findings, owners and contractors have differences and s


Reference class forecasting for Hong Kong’s major roadworks projects

Bent Flyvbjerg
Chi-keung Hon
Wing Huen Fok

Proceedings of the Institution of Civil Engineers - Civil Engineering

Abstract: Reference class forecasting is a method to remove optimism bias and strategic misrepresentation in infrastructure projects and programmes. In 2012 the Hong Kong government’s Development Bureau commissioned a feasibility study on reference class forecasting in Hong Kong – a first for the Asia-Pacific region. This study involved 25 roadwork projects, for which forecast costs and durations were compared with actual outcomes. The analysis established and verified the statistical distribution of the forecast accuracy at various stages of project development, and benchmarked the projects against a sample of 863 similar projects. The study contributed to the understanding of how to improve forecasts by de-biasing early estimates, explicitly considering the risk appetite of decision makers, and safeguarding public funding allocation by balancing exceedance and under-use of project budgets.


Planning and Estimation of Operations Support Requirements

Abstract: Life Cycle Cost (LCC) estimates during the proposal and early design phases, as well as project replans during the development phase, are heavily focused on hardware development schedules and costs. Operations (phase E) costs are typically small compared to the spacecraft development and test costs. This, combined with the long lead time for realizing operations costs, can lead to de-emphasizing estimation of operations support requirements during proposal, early design, and replan cost exercises. The Discovery and New Frontiers (D&NF) programs comprise small, cost-capped missions supporting scientific exploration of the solar system. Any LCC growth can directly impact the programs' ability to fund new missions, and even moderate yearly underestimates of the operations costs can present significant LCC impacts for deep space missions with long operational durations. The National Aeronaut


Advances in Difference-in-differences Methods for Policy Evaluation Research

Abstract: Difference-in-differences (DiD) is a powerful, quasi-experimental research design widely used in longitudinal policy evaluations with health outcomes. However, DiD designs face several challenges to ensuring reliable causal inference, such as when policy settings are more complex. Recent economics literature has revealed that DiD estimators may exhibit bias when heterogeneous treatment effects, a common consequence of staggered policy implementation, are present. To deepen our understanding of these advancements in epidemiology, in this methodologic primer, we start by presenting an overview of DiD methods. We then summarize fundamental problems associated with DiD designs with heterogeneous treatment effects and provide guidance on recently proposed heterogeneity-robust DiD estimators, which are increasingly being implemented by epidemiologists. We also extend the discussion to violatio


Curbing cost overruns in infrastructure investment

European journal of transport and infrastructure research

Abstract: Infrastructure projects around the world have long been notorious for exceeding their budgets. To address persistent cost overruns, the American Planning Association urged planners to adopt reference class forecasting alongside traditional methods but the practice has not caught on in the U.S. Conversely, the U.K. adopted Kahneman’s Nobel Prize-winning theory to challenge biases in human judgment and mandated reference class forecasting for major projects in 2003. Has reference class forecasting, originally developed to rectify honest mistakes, brought the promised success in the public sector wherein political pressure is significant? Through before-and-after and with-and-without comparisons of 107 major projects, this empirical study examines the practical relevance of reference class forecasting for infrastructure investments. A before-and-after comparison reveals that the average cos


Planning Fallacy or Hiding Hand: Which Is the Better Explanation?

Abstract: This paper asks and answers the question of whether Kahneman's planning fallacy or Hirschman's Hiding Hand best explain performance in capital investment projects. I agree with my critics that the Hiding Hand exists, i.e., sometimes benefit overruns outweigh cost overruns in project planning and delivery. Specifically, I show this happens in one fifth of projects, based on the best and largest dataset that exists. But that was not the main question I set out to answer. My main question was whether the Hiding Hand is "typical," as claimed by Hirschman. I show this is not the case, with 80 percent of projects not displaying Hiding Hand behavior. Finally, I agree it would be important to better understand the circumstances where the Hiding Hand actually works. However, if you want to understand how projects "typically" work, as Hirschman said he did, then the theories of the planning fallac


Analysis of the Delay Risk of the Engineering, Procurement, Construction, and Commissioning (EPCC) Phases in Oil and Gas Industry Projects

Engineering, Technology & Applied Science Research

Abstract: EPCC projects in the oil and gas industry are highly complex and carry significant risks of delays and cost overruns. This study aims to identify and analyze the dominant delay risk factors across each phase of EPCC, using the Matindok Gas Development Project in Central Sulawesi, Indonesia, as a case study. The project was originally scheduled for completion within 26 months, but experienced a time extension of up to 12 months. Data collection was conducted through a literature review and the distribution of questionnaires. Risk evaluation was performed based on the probability and impact of each factor using the Risk Priority Number (RPN) method. The results show that the most critical risk factors include design changes by the project owner during the engineering phase (RPN = 13.21), poor cash flow of the parent company in the procurement phase (RPN = 13.2), work sequence conflicts in


The concept of red tape and efficiency among corporate and government manager: Analysis on the effects to their management performances

Abstract: Red tape, characterized by excessive bureaucracy, rigid procedures, and unnecessary administrative burdens, stifles efficiency, creates frustration, and demotivates employees. When organizations are entrenched in red tape, employees often feel constrained by outdated systems and are discouraged from taking initiative or suggesting improvements. This leads to a lack of innovation, slow decision-making, and reduced responsiveness to changing circumstances. This exploratory study analyzed culture of red tape in corporate government setting. This study also provided perspectives on developing efficient bureaucratic culture in these work settings. Corporate and government managers (n=30) were purposively sampled to be interviewed in this study. Their narratives reflected their experiences in dealing with red tape cultures, and how they responded to workplace constraints. Findings indicated th


Toward a Deeper Understanding of Optimism Bias and Transport Project Cost Overrun

Yizi Chen
Dominic D. Ahiaga-Dagbui
Muhammad Jamaluddin Thaheem
Asheem Shrestha

Abstract: There is a growing face-value acceptance of optimism bias as the primary cause of transport cost overruns. This article provides a timely review of literature on optimism bias and transport infrastructure project cost overruns. The article identifies significant gaps and unanswered questions about the relationship between optimism bias in project cost appraisal and cases of transport infrastructure cost overruns. The presence and nature of optimism bias in the complex institutional environment of project cost appraisal are largely understudied and not well understood. Consequently, this has significant implications for the development of effective mitigation strategies for improving transport project cost performance.


Cost Overrun Optimism: Fact of Fiction?

Abstract: Program managers are advocates by necessity. When taken to the extreme, program advocacy can result in the suppression of adverse information about the status of a program. Such was the case in the Navy’s A-12 program. In “A-12 Administrative Inquiry,” Beach (1990) speculates that such “abiding cultural problems” were not unique to the Navy. To test that assertion, this article examines cost overrun data on 64 completed acquisition contracts extracted from the Defense Acquisition Executive Summary database. Cost overruns at various contract completion points are compared with projected final cost overruns estimated by contractor and government personnel. The comparison shows that the overruns projected by the contractor and government were excessively optimistic throughout the lives of the contracts examined. These results were found insensitive to contract type (cost, price), contract p


Quality-Induced Impacts on Time Overrun, Cost Overrun, Dispute, and Litigation in EPC Contracts

Abstract: Abstract: This research paper delves into the intricate relationship between quality assurance measures and their consequential effects on time overrun, cost overrun, disputes, and litigation within Engineering, Procurement, and Construction (EPC) contracts of National Highway. Through an extensive qualitative study and in-depth analysis in SPSS, this paper aims to shed light on the critical high risk contract clauses which make project delays, budget overruns, and legal conflicts impacted by quality. The findings presented herein offer valuable insights for stakeholders in the construction industry seeking to enhance project performance and minimize legal liabilities through effective quality control mechanisms. Contractors, consultants, and employees of the authority were handed a questionnaire survey as part of this investigation. Google Forms was used to gather 161 replies. Principal


Investigating Cost Overrun Factors in High-Rise Housing Projects in India

Abstract: Cost overruns in building projects are typical in India. This might occur owing to a variety of factors. The aim of the study was to identify the factors impacting high-rise housing project costs in India, that are likely regulatable by head contractors. A questionnaire survey was used to perform this study with a group of related professionals from firms in the private as well as public sectors, having experience in high-rise housing projects. The frequency and impact of each factor were assessed based on the perspectives of the participants. The factors were then rated in order of the increasing Index of Relative Importance. The study identified significant factors that are likely to be regulated by head contractors, namely, productivity of labor, the performance of suppliers and sub-contractors, productivity of equipment, poor management of the site, scheduling, controlling and monito


Reference Class Forecasting and Machine Learning for Improved Offshore Oil and Gas Megaproject Planning: Methods and Application

Abstract: This article develops and describes rigorous oil and gas project forecasting methods. First, it builds a theoretical foundation by mapping megaproject performance literature to these projects. Second, it draws on heuristics and biases literature, using a questionnaire to demonstrate forecasting-related biases and principal-agent issues among industry project professionals. Third, it uses methodically collected project performance data to demonstrate that overrun distributions are non-normal and fat-tailed. Fourth, reference-class forecasting is demonstrated for cost and schedule uplifts. Finally, a predictive approach using machine learning (ML) considers project-specific factors to forecast the most likely cost and schedule overruns in a project.


The processes of public megaproject cost estimation: The inaccuracy of reference class forecasting

Abstract: AbstractGovernments worldwide are introducing “reference class forecasting” to improve the accuracy of megaproject cost estimation and thus ultimately the ability to deliver megaprojects on budget without altering the project specifications and/or changing the time schedule. In contrast to current findings, which show that reference class forecasting leads to more accurate project cost estimates by counteracting human cognitive and organizational biases, this article indicates the contrary, that reference class forecasting doesnotlead to more accurate cost estimates. The article theorizes that reference class forecasting fails to produce more accurate project cost estimates because estimates are always a relational network effect of human and nonhuman actors’ “biased” efforts to establish them. This finding challenges the existing literature by pointing to a more complex understanding of


Affordability assessments to support strategic planning and decisions at NASA

Debra Emmons
Marcus Lobbia
Torrey Radcliffe
Robert Bitten

Abstract: NASA's goal to provide a human presence in space while contributing to the knowledge of the science of Earth, other planets, the solar system, and the universe requires a diverse set of scientific and exploration missions. Successful development and execution of these portfolios depends upon a sustainable and affordable long-term strategy. To provide a basis for an adequate annual funding profile to fit within NASA's budget, an objective affordability assessment of a mission's technical baseline, associated risks, and cost and schedule is fundamental. For example, NASA's Science Mission Directorate lists close to 100 planned science missions for launch within a 20-year window in the Agency Mission Planning Manifest maintained by the NASA Office of Program Analysis and Evaluation. On the human space flight side, the NASA Exploration Systems Mission Directorate (ESMD) is in the process of


Delays and Cost Overruns in Infrastructure Projects -- An Enquiry into Extents, Causes and Remedies

Abstract: Media reports abound on instances of prolonged delays and excessive cost overruns in infrastructure projects. Only a small number of projects get delivered in time and within the budget. Examples of successful project implementation, like construction of the Delhi Metro Rail, are few and appear only far in between. Indeed, the problem of time and cost overruns in India is widespread and severe. Yet, very few empirical studies exist on the subject. Even rarer are the studies based on completed projects. As a result, the extents as well as the causes behind delays and cost overruns have remained under-researched. This study investigates the various issues related to delays and cost overruns in publically funded infrastructure projects. The following questions are posed and answered -- How common and how large are the time and the cost overruns? What are the essential causes behind these de


Megaproject policy and planning: Problems, causes, cures

VBN Forskningsportal (Aalborg Universitet)

Abstract: This paper focuses on problems in megaproject policy and planning and their causes and possible cures.After considerations of methodology, the paper first identifies as a main problem in megaproject development pervasive misinformation about the costs, benefits, and risks involved.A consequence of misinformation is cost overruns, benefit shortfalls, and waste.Second, the paper explores the causes of misinformation and finds that political-economic explanations best account for the available evidence: planners and promoters deliberately misrepresent costs, benefits, and risks in order to increase the likelihood that it is their projects, and not the competition's, that gain approval and funding.This results in the "survival of the unfittest," where often it is not the best projects that are built, but the most misrepresented ones.Finally, the paper presents measures for reforming megaproj


NASA Standing Review Board Handbook

Abstract:
This handbook provides guidance based on best practices for the planning, preparation, review, reporting, and closeout of Standing Review Board (SRB) activities.

 Revision C updates the Revision B version of the SRB Handbook published in 2016 to incorporate updates to NASA Procedural Requirements (NPR) 7120.5F, NASA Space Flight Program and Project Management Requirements. These updates include:
 - Changing the Dissenting Opinion process to the Formal Dissent process, which retains the current process augmented with an expedited escalation path.
 - Updates to requirements for establishing an Agency Baseline Commitment (ABC) and for performing Joint Cost and Schedule Confidence Level (JCL) analyses for tightly coupled programs.
 - Additional requirements for performing a JCL analysis for single-project programs and projects over $1B Life-Cycle Cost (LCC).
 - Use of initial capability cos


Operationalizing Transaction Cost Economics for Contract Governance: Evidence from Procurement Data

Abstract: Selecting an appropriate contract type is a central decision in purchasing and supply management, shaping incentives, risk allocation, and buyer–supplier relationships. Drawing on Transaction Cost Economics (TCE), this study examines how observable procurement characteristics can inform contract governance choice. Using a dataset of over 2,500 U.S. federal service contracts, we develop and test empirical models that relate contract attributes—such as competition structure, subcontracting, performance specifications, and contract value—to governance form (fixed price versus cost plus), providing a large-scale empirical setting with broader implications for procurement and supply chain governance. Our results provide large-sample evidence that commonly available procurement data serve as meaningful proxies for transaction cost dimensions, including asset specificity and complexity. Several


A study of stakeholders' procurement deficiencies, delays and cost overruns in Tanzania's construction projects

International Journal of Procurement Management


Assessment of delay and cost-overrun in federal road construction project in Abuja

Abstract: Poor road infrastructure in Nigeria is a significant challenge, just like poverty, insecurity, and unemployment. The construction of road in the country is characterized by numerous challenges throughout the project life cycle. Some of these challenges are project delay and cost overrun, corruption and fraud, faulty contractual process among others. Objectives of this study are to identify factors influencing delays and cost overruns in road construction project, to rank these factors base on their impacts and importance, and to suggest conservative ways to address the future challenges that can result from delays and cost overruns of future road construction projects. The research instruments include in-depth literature review, fieldwork, questionnaire administration, and interview. Inferential statistics such as Relative importance index (RII) and Mean Value techniques were used to ana


OUTSOURCING: TRANSACTION COST ECONOMICS AND SUPPLY CHAIN MANAGEMENT*

Abstract: This article examines outsourcing from the transaction cost economics (TCE) perspective. The transaction is made the basic unit of analysis and the procurement decision, as between make and buy, is made (principally) with reference to a transaction cost economizing purpose. As sketched herein, the ease of contracting varies with the attributes of the transaction, with special emphasis on whether preserving continuity between a particular buyer–seller pair is the source of added value. The basic regularity is this: as bilateral dependency builds up, the efficient governance of contractual relations progressively moves from simple market exchange to hybrid contracting (with credibility supports) to hierarchy. This last corresponds to the “make” decision, which, as viewed from the TCE perspective, is viewed as the organization form of last resort. The article successively describes the lens


Math is EZIE: How Contracts Help Control Cost

Abstract: The aerospace cost estimating community relies on risk analyses to estimate confidence in a project's budget. At a NASA mission's preliminary design review (PDR), convention requires that baseline cost confidence plus project-held reserves should be around the 50th percentile and cost plus project-held reserves and unallocated future expenses (UFE) should be around the 70th percentile of the joint distribution of total cost and schedule. But how can we test whether our approach to determining 50th and 70th percentiles for missions going into PDR is reliable? An analysis of historical costs from past NASA missions shows that there is an 84 % chance that a mission will experience cost growth from PDR to Launch. At the empirical 50th and 70th percentiles, NASA missions are spending their full budgets plus 16% and 27 %, respec


Joint Confidence Level Requirement: Policy and Issues

Abstract: NASA is in the midst of implementing a Joint Confidence Level (JCL) requirement for all project and programs. It extends the previous cost estimate confidence requirement by incorporating schedule confidence as well. At first glance, the JCL target level seemed reasonable in light of project management's general desire to monitor both cost and schedule closely. In practice, however, despite the many merits of this requirement, it introduces unintended consequences that establish potentially insurmountable challenges to most projects and programs. In levying a cost confidence requirement on a program with many tightly coupled projects, there is a beneficial effect provided by portfolio diversification because cost and budgets are fungible; program managers can transfer money from a project in surplus to another in shortage. This also means that projects can be budgeted at a lower cost con


To collaborate or not to collaborate: A transaction cost economics approach to construction contracts in public-private partnerships

Journal of Sustainable Development Law and Policy

Abstract: Public-Private Partnerships (PPPs) are often seen as a cost-effective way of providing public infrastructure. However, mega-construction projects involve many hidden costs that arise during the project life cycle. These costs are known as transaction costs. This article investigates how a construction contract under a PPP can reduce transaction costs. Using Transaction Cost Economics (TCE), the article draws on empirical studies from six countries to identify four factors that affect transaction costs in construction contracts namely: (i) Concessionaire predictability, (ii) Contractor predictability, (iii) Project Management Efficiency, and (iv) Project Environment Uncertainty. Different types of construction contracts were comparatively analysed against the aforementioned four factors. The findings indicate that collaborative contracts are more likely to favourably address these four fa


The Dynamics of Congressional Committees in Budget Legislation and Its Impact to Philippine Economic Development

Journal of Contemporary Sociological Issues

Abstract: This research examines the dynamics of the 17th congress in the budget legislation process and posts an argument regarding its impact on Philippine economic development using a qualitative research design. The researchers use theoretical debate and literature study to identify the political motivations that affect the Congressmen in the approval of the budget, namely: self-interest, political clientelism, and political interference. An online interview was conducted with the selected key informants to know the significance of each factor in congress's decision-making regarding the budget's approval. The results indicate that self-interest, political clientelism, political interference, and the executive department significantly influence the congressional committees on the budget legislation process. This article concludes that the effectiveness of lawmakers' roles in managing the econom


ELEMENTS OF COST AND SCHEDULE OVERRUN IN CONSTRUCTIONPROJECTS

Indonesian Journal of Engineering Research

Abstract: The cost of a basic upgrade to this wonderful piece of study is typically expressed in necessary units like earned dollars. The economic activity necessary to ensure that the building projects are sufficiently finished within an approved budget is properly included in the Project Cost. Although having more practical experience in construction management, cost and schedule overruns still play a significant role in many projects. Modern literatures are studied back-to-back and divided into two parts, which costs money for particular projects, overrunning of schedules in construction projects. The main study establishes that price increase causes cost and schedule overruns. For all intents and purposes, any client who is interested in facilities in the manufacturing sector is complete in terms of scope, timing, and cost. These studies have been published under a creative commons permission


Evolving management strategies to improve NASA flagship’s cost and schedule performance: LUVOIR as a case study

Abstract: The large ultraviolet optical infrared surveyor (LUVOIR) study process has brought to fruition an extremely exciting scientific mission concept. The 3.5 year LUVOIR study duration enabled an unprecedented level of scientific, engineering, and technology thoroughness prior to the Astro2020 Decadal. This detail also shed light on many technical and programmatic challenges for efficiently developing a mission of this scale within the context of NASA’s flagships cost and schedule performances to date. While NASA’s flagships perform exquisitely once onorbit, there is understandable growing frustration in their development cost and schedule overruns. We felt it incumbent upon ourselves to ask how we could improve on delivering LUVOIR (or any of NASA’s future flagships) on schedule and on budget, not just for the next mission, but for all NASA large strategic missions to come. We researched pas


Institutions and Economic Theory

Abstract: Editor’s Introduction Originally published in Volume 36, Number 1, Spring 1992, pages 3-6. Omicron Delta Epsilon presented Douglass North (1920-2015) with the John R. Commons award in 1992 for his contributions to the economics profession. The following year he shared the Nobel Memorial Prize in Economic Sciences with Robert Fogel. The Nobel honored their work in applying economic theory and quantitative methods to the study of economic history and institutional change. As a pioneer in what has become known as cliometrics (named for the classical muse of history, Clio), Professor North’s scholarship focused on how human institutions and their organizational structures influence economic and societal outcomes. He is widely recognized as one of the founders of the New Institutional Economics school of thought. In this paper, his Commons Award lecture, Professor North describes and discusse


Delays and Cost Overruns in Infrastructure Projects: Extent, Causes and Remedies

Abstract: This study, based on a large dataset of 894 projects from 17 infrastructure sectors, attempts to answer certain important questions on time and cost overruns in publicly-funded infrastructure projects: How common and how large are the overruns? What are the essential causes? Are contractual and institutional failures among the significant causes? What are the policy implications for planning, development and implementation of infrastructure projects? Among other results of an econometric analysis, the study shows that the contractual and institutional failures are economically and statistically significant causes behind cost and time overruns.


Panel Models in Sociological Research: Theory into Practice

Abstract: A selection of panel studies appearing in the American Sociological Review and the American Journal of Sociology between 1990 and 2003 shows that sociologists have been slow to capitalize on the advantages of panel data for controlling unobservables that threaten causal inference in observational studies. This review emphasizes regression methods that capitalize on the strengths of panel data for consistently estimating causal parameters in models for metric outcomes when measured explanatory variables are correlated with unit-specific unobservables. Both static and dynamic models are treated. Among the major subjects are fixed versus random effects methods, Hausman tests, Hausman-Taylor models, and instrumental variables methods, including Arrelano-Bond and Anderson-Hsaio estimation for models with lagged endogenous variables.


The NPG 7120.5A Electronic Review Process

Abstract: The use of electronics to review a document is well within the technical realm of today's state-of-the-art workplace. File servers and web site interaction are common tools for many NASA employees. The electronic comment processing described here was developed for the NPG 7120.5A review to augment the existing NASA Online Directives Information System (NODIS). The NODIS system is NASA's official system for formal review, approval and storage of NASA Directives. The electronic review process worked so well that NASA and other agencies may want to consider it as one of our "best practices." It was participatory decision making at its very best, a process that attracted dozens of very good ideas to improve the document as well as the way we can be managing projects far more effectively. The revision of NPG 7120.5A has significant implications for the way all elements of the Agency accomplis


Reducing NPR 7120.5D to Practice: Preparing for a Life-Cycle Review

Abstract: In March 2007, NASA issued revised rules for space flight project management, NPR 7120.5D, 'NASA Space Flight Program and Project Management Requirements.' Central to the new rules was the construct of Key Decision Points, maturity gates that the project team must pass in order to continue development. In order that the KDP decision be fully informed, the NPR required, as entrance criteria for the gate, the generation and delivery of specified planning, technical, and cost/schedule documents (gate products) and a life-cycle review, the Preliminary Design Review. Building on JPL experience on the Prometheus and Juno projects, the team successfully organized for and conducted these reviews on an aggressive schedule. Key actions were taken to proactively interact with the SRB, produce high-quality gate products with stakeholder review, generate review presentation materials, and handle a my


Composite Crew Module: Primary Structure

Abstract: In January 2007, the NASA Administrator and Associate Administrator for the Exploration Systems Mission Directorate chartered the NASA Engineering and Safety Center to design, build, and test a full-scale crew module primary structure, using carbon fiber reinforced epoxy based composite materials. The overall goal of the Composite Crew Module project was to develop a team from the NASA family with hands-on experience in composite design, manufacturing, and testing in anticipation of future space exploration systems being made of composite materials. The CCM project was planned to run concurrently with the Orion project's baseline metallic design within the Constellation Program so that features could be compared and discussed without inducing risk to the overall Program. This report discusses the project management aspects of the project including team organization, decision making, inde


Making or buying evidence: Using transaction cost economics to understand decision-making in public school districts

Z. Neal
Jennifer Watling Neal
Kristen J. Mills
Jennifer A. Lawlor

Evidence & Policy: A Journal of Research, Debate and Practice

Abstract: We propose transaction cost economics theory as a tool for exploring when school administrators rely on information from two types of sources: internal sources like their own colleagues, and external sources like researchers and government agencies. The theory’s application is illustrated in a comparative case study of two public school districts in Michigan. Consistent with the theory’s predictions, the smaller, homogeneous, high-performing district used more external sources of information, while the larger, diverse, low-performing district used internal sources of information. We conclude by identifying some strengths and limitations of the theory, which can serve as starting points for debate.


Estimating incremental cost and schedule growth for systems engineering and project management


Evaluating policy impact under sparse and staggered adoption. A synthetic difference-in-differences application to EU rural development measures.

Abstract: This paper investigates how farmers respond to targeted policy measures under the EU Common Agricultural Policy (CAP), focusing on whether voluntary adoption, often driven by private motivations, also leads to outcomes of societal interest. To address the methodological challenges posed by staggered and sparse treatment adoption, the study employs a Synthetic Difference-in-Differences (SDID) approach. A theoretical framework is developed to distinguish between private and societal outcomes of policy adoption. The empirical analysis uses a balanced panel of Italian farms from 2014 to 2022 and focuses on selected second-pillar CAP measures. Results reveal that while some measures significantly affect private outcomes (e.g., farm income or productivity), their impact on societal outcomes (e.g., environmental indicators) is weaker and more volatile. The paper discusses key challenges in iden


Difference-in-Differences with a Continuous Treatment

Brantly Callaway
Andrew Goodman-Bacon
Pedro H. C. Sant’Anna

Abstract: This paper analyzes difference-in-differences designs with a continuous treatment. We show that treatment-on-the-treated-type parameters are identified under a parallel trends assumption analogous to the binary treatment case. However, comparing these parameters across treatments is challenging because parallel trends does not rule out selection bias. We discuss alternative, typically stronger, assumptions that eliminate selection bias. We further show that popular two-way fixed effects estimands admit multiple interpretations, depending on the underlying causal building block, all having important limitations as meaningful summaries of treatment effects. Finally, we introduce alternative estimation procedures that avoid these drawbacks and demonstrate them in an empirical application.


Predicting Cost and Schedule Growth for Military and Civil Space Systems

Defense Technical Information Center (DTIC)

Abstract: This research seeks to identify factors contributing to military and civil space system cost and schedule growth, quantify the relative impact of these factors, and establishing a set of models for predicting cost and schedule growth. The analysis consists of logistic and multiple regression to assess 21 Department of Defense and 71 National Aeronautics and Space Administration (NASA) space programs. The study finds that, for military spaces systems, communications missions, ground equipment, firm-fixed price contracts, and increased program manager tenure are all predictive of lower cost growth. For NASA space programs, the study finds that smaller programs (by total cost), more massive spacecraft, microgravity missions, and space physics missions are predictive of higher cost growth. For schedule growth of NASA programs, the study finds that larger programs and those developed by the J


Constellation Program Life-cycle Cost Analysis Model (LCAM)

Abstract: The Constellation Program (CxP) is NASA's effort to replace the Space Shuttle, return humans to the moon, and prepare for a human mission to Mars. The major elements of the Constellation Lunar sortie design reference mission architecture are shown. Unlike the Apollo Program of the 1960's, affordability is a major concern of United States policy makers and NASA management. To measure Constellation affordability, a total ownership cost life-cycle parametric cost estimating capability is required. This capability is being developed by the Constellation Systems Engineering and Integration (SE&I) Directorate, and is called the Lifecycle Cost Analysis Model (LCAM). The requirements for LCAM are based on the need to have a parametric estimating capability in order to do top-level program analysis, evaluate design alternatives, and explore options for future systems. By estimating the total cost


Deterministic Decision Authority: A Governance-First Architecture for Human-Final AI Systems

Abstract: Artificial intelligence systems increasingly participate in high-impact decision processes, yet most existing architectures lack a deterministic answer to a fundamental question: who ultimately holds decision authority. This paper introduces Deterministic Decision Authority (DDA), a governance-first architectural framework designed to enforce human-final authority over AI-assisted decisions through mathematically defined constraints, irreversibility controls, and deterministic decision replay. Unlike conventional AI governance approaches that rely on post-hoc explainability or probabilistic alignment, DDA establishes decision authorization as a formally bounded process, separating intelligence generation from decision approval. The architecture integrates a non-modifiable decision core, a human-final governance layer, auto-lock mechanisms


Modern Staggered Difference-in-Differences: From the Pitfalls of Two-Way Fixed Effects (TWFE) to Robust Estimation


Lifecycle Cost Affordability and Performance-Based Contracting – A Managerial Decision Framework Based on Literature Review

Operations and Supply Chain Management An International Journal

Abstract: This manuscript reviews and synthesizes the product service system, lifecycle affordability, and performance-based contracting (PBC) literature across supply chain management, operations management, and logistics discipline.The study is based on 128 peer-reviewed articles published between 2005 and 2023 in journals related to the supply chain, logistics, and operations management field.The study proposes a framework for lifecycle affordability (LCA) and key aspects of performancebased strategy design and management, performance specification, and cost elements.This study is a robust literature review of lifecycle affordability and performance-based contracting.It proposes a framework to assist in business-tobusiness managerial decision-making to reduce lifecycle costs.


Implementing an Objectives-Driven, Risk-Informed, and Case-Assured Approach to Safety and Mission Success at NASA

Abstract:
NASA is developing a “Standard for Assurance of Space Flight Safety and Mission Success” that implements an objectives-driven, risk-informed, and case-assured approach to safety and mission success (S&MS) for NASA space flight programs and projects. The standard aligns with the philosophy of risk leadership that has recently been established in NASA policy to assure acceptable levels of flight crew safety and mission success risk. It is consistent with existing NASA risk management requirements and is compatible with NASA program management and systems engineering requirements.

The methodology described in the standard is presented in terms of an S&MS assurance framework that is designed to allow substantial flexibility in the specific means by which programs and projects achieve acceptable mission S&MS risk. Such flexibility is necessary to accommodate the increasingly broad range of a


Red tape reform, transaction costs, and corporate social performance: A natural quasi-experiment in China

Abstract: Abstract The question of how government red tape affects corporate social performance (CSP) has received little attention. Based on the transaction cost and institutional theories, we hypothesize a theoretical link between external red tape and CSP. We employ a natural quasi-experiment based on the gradual rollout in some cities of administrative licensing centers, which aimed to reduce red tape and link these with firm-level charitable donation data from 1998 to 2016. Results show that red tape reform improved CSP by reducing corporate efficiency-based transaction costs and that this facilitating effect is heterogeneous in terms of red tape reform characteristics. Our study advances external red tape research by confirming the positive role of red tape reform in fostering socially conscious stakeholder behavior.


Artificial Intelligence Enabled Project Management: A Systematic Literature Review

Ianire Taboada
Abouzar Daneshpajouh
Nerea Toledo
Tharaka de Vass

Abstract: In the Industry 5.0 era, companies are leveraging the potential of cutting-edge technologies such as artificial intelligence for more efficient and green human-centric production. In a similar approach, project management would benefit from artificial intelligence in order to achieve project goals by improving project performance, and consequently, reaching higher sustainable success. In this context, this paper examines the role of artificial intelligence in emerging project management through a systematic literature review; the applications of AI techniques in the project management performance domains are presented. The results show that the number of influential publications on artificial intelligence-enabled project management has increased significantly over the last decade. The findings indicate that artificial intelligence, predominantly machine learning, can be considerably usef


Two-Way Fixed Effects and Difference-in-Differences Estimators with Heterogeneous Treatment Effects and Imperfect Parallel Trends

Clément de Chaisemartin
Xavier d'Haultfoeuille


Synthetic Difference-In-Differences Estimation With Staggered Treatment Timing


Causal inference with imperfect instrumental variables

Nikolai Miklin
Mariami Gachechiladze
George Moreno
Rafael Chaves

Abstract:
Abstract
                  Instrumental variables allow for quantification of cause and effect relationships even in the absence of interventions. To achieve this, a number of causal assumptions must be met, the most important of which is the independence assumption, which states that the instrument and any confounding factor must be independent. However, if this independence condition is not met, can we still work with imperfect instrumental variables? Imperfect instruments can manifest themselves by violations of the instrumental inequalities that constrain the set of correlations in the scenario. In this article, we establish a quantitative relationship between such violations of instrumental inequalities and the minimal amount of measurement dependence required to explain them for the case of discrete observed variables. As a result, we provide adapted inequalities that are valid in


Issues in NASA program and project management

NASA STI Repository (National Aeronautics and Space Administration)

Abstract: This collection of papers and resources on aerospace management issues is inspired by a desire to benefit from the lessons learned from past projects and programs. Inherent in the NASA culture is a respect for divergent viewpoints and innovative ways of doing things. This publication presents a wide variety of views and opinions. Good management is enhanced when program and project managers examine the methods of veteran managers, considering the lessons they have learned and reflected on their own guiding principles.


Transaction cost economics of procurement models in public transport: An institutional perspective

Abstract: Abstract In recent years, concern has grown over good practices in the procurement processes in public transport. Although promoting competition by competitive tendering to gain efficiency and increase service quality has gradually become common around the world, the applicability of this model in weak institutional environments has some uncertainties. Drawing from new institutional economics (NIE) literature, transaction cost economics (TCE) approach presents important theoretical insights to comprehend the nature of authority and operator relations by underlining the institutional factors that make such procurements effective or not. We argue in this paper that the extent to which transaction structures are embedded in the institutional framework has a substantial impact on the long-run performance of the public transport contracts. A case study of the experience of Istanbul’s public b


Systematic Literature Review: How is Model-Based Systems Engineering Justified?

Abstract: The genesis for this systematic literature review was to search for industry case studies that could inform a decision of whethe r or not to support the change process, investment, training, and tools needed to implement an MBSE approach across the engineering enterprise . The question asked was, how the change from a document - based systems engineering approach (DBSE) to a model - base d systems engineering approach (MBSE) is justified? The methodology employed for this systematic literature review was to conduct a document search of electronically published case studies by authors from the defense, space, and complex systems product eng ineering industries. The 67 case studies without metrics mainly attributed success to completeness, consistency, and communication of requirements. The 21 case studies with metrics on cost and schedule primarily attributed success to the ability of an


The Cost Impacts of Jointness: Insights From the NPOESS Program

Morgan Dwyer
Zoe Szajnfarber
Bruce Cameron
Markus Bradford
Ed Crawley

Abstract: Although joint programs are typically formed to reduce costs, recent studies have suggested that they may actually be more costly than non-joint programs. In this paper, we explore this hypothesis using an in-depth case study of the NPOESS program. To study jointness, we apply a semi-quantitative framework that quantifies the complexity impacts of jointness and enables us to observe their evolution over time. In particular, we describe how jointness impacted the NPOESS program???by inducing technical and organizational complexity???and illustrate how the relationship between both complexity types enabled, sustained, and induced cost growth. We also explain the evolution of the program???s technical and organizational complexity by identifying five key technical decisions and collaborating agency interactions that increased complexity and cost. Finally, we conclude by noting that a key so


Explaining Fixed Effects: Random Effects Modeling of Time-Series Cross-Sectional and Panel Data

Abstract: This article challenges Fixed Effects (FE) modeling as the ‘default’ for time-series-cross-sectional and panel data. Understanding different within and between effects is crucial when choosing modeling strategies. The downside of Random Effects (RE) modeling—correlated lower-level covariates and higher-level residuals—is omitted-variable bias, solvable with Mundlak's (1978a) formulation. Consequently, RE can provide everything that FE promises and more, as confirmed by Monte-Carlo simulations, which additionally show problems with Plümper and Troeger's FE Vector Decomposition method when data are unbalanced. As well as incorporating time-invariant variables, RE models are readily extendable, with random coefficients, cross-level interactions and complex variance functions. We argue not simply for technical solutions to endogeneity, but for the substantive importance of context/heterogene


The SAGE Handbook of Regression Analysis and Causal Inference

Abstract: Introduction - Christof Wolf and Henning Best PART I: ESTIMATION AND INFERENCE Estimation Techniques: Ordinary least squares and maximum likelihood - Martin Elff Bayesian Estimation of Regression Models - Susumu Shikano PART II: REGRESSION ANALYSIS FOR CROSS-SECTIONS Linear Regression - Christof Wolf and Henning Best Regression Analysis: Assumptions and Diagnostics - Bart Meuleman, Geert Loosveldt and Viktor Emonds Non-Linear and Non-Additive Effects in Linear Regression - Henning Lohmann The Multilevel Regression Model - Joop Hox and Leoniek Wijngaards-de Meij Logistic Regression - Henning Best and Christof Wolf Regression Models for Nominal and Ordinal Outcomes - J. Scott Long Graphical Display of Regression Results - Gerrit Bauer Regression With Complex Samples - Steven G. Heeringa, Brady T. West and Patricia A. Berglund PART III: CAUSAL INFERENCE AND ANALYSIS OF LONGITUDINAL DATA Mat


Defense Acquisition: Overview, Issues, and Options for Congress

University of North Texas Digital Library (University of North Texas)

Abstract: Department of Defense (DOD) activities to provide military capabilities for the defense of the nation are usually controversial and always complex. Those activities are generally referred to as defense acquisition. The structure DOD utilizes to plan, execute and oversee those activities is a highly intricate and multi-variate "system of systems" composed of the requirements, resource allocation and acquisition systems. This system of systems has evolved over time, its foundation being the report published by the Packard Commission in 1986, with many of those recommendations becoming part of the Goldwater-Nichols Department of Defense Reorganization Act of 1986. This evolution continued after the Goldwater-Nichols Act as the requirements system changed from a threat-based to a capabilities-based system; the resource allocation system added execution reviews and concurrent program and budg


Testing alternative theories of the firm: transaction cost, knowledge-based, and measurement explanations for make-or-buy decisions in information services

Abstract: Firms boundary choices have undergone careful examination in recent years, particularly in information services. While transaction cost economics provides a widely tested explanation for boundary choice, more recent theoretical work advances competing knowledge-based and measurement cost explanations. Similar to transaction cost economics, these theories examine the impact of exchange attributes on the performance of markets and hierarchies as institutions of governance. These theories, however, offer alternative attributes to those suggested by transaction cost economics or offer alternative mechanisms through which similar attributes influence make–buy choices. Traditional empirical specifications of make–buy models are unable to comparatively test among these alternative theories. By developing and testing a model of comparative institutional performance rather than institutional choi


Real-time data acquisition at mission control

John F. Muratore
Troy A. Heindel
Terri B. Murphy
Arthur N. Rasmussen
Robert Z. Mcfarland

Abstract: Perhaps one of the most powerful symbols of the United States' technological prowess is the Mission Control Center (MCC) at the Lyndon B. Johnson Space Center in Houston. The rooms at Mission Control have been witness to major milestones in the history of American technology such as the first lunar landing, the rescue of Skylab, and the first launch of the Space Shuttle. When Mission Control was first activated in the early 1960s it was truly a technological marvel. This facility, however, has received only modest upgrades since the Apollo program. Until recently it maintained a mainframe-based architecture that displayed data and left the job of data analysis to flight controllers. The display technology utilized in this system was monochrome and primarily displayed text information with limited graphics (photo 1). An example display of 250 communication parameters is shown in Figure 1.


The economic institutions of capitalism firms, markets, relational contracting

Abstract: This study is based on the belief that economic organization is shaped by transaction cost economizing decisions. It sets out the basic principles of transaction cost economics, applies the basic arguments to economic institutions, and develops public policy implications. Any issue that arises, or can be recast as a matter of contracting, is usefully examined in terms of transaction costs. Transaction cost economics maintains that governance of contractual relations is mainly achieved through institutions of private ordering instead of legal centralism. This approach is based on behavioral assumptions of bounded rationalism and opportunism, which reflect actual human nature. These assumptions underlie the problem of economic organization: to create contract and governance structures that economize on bounded rationality while safeguarding transactions against the hazards of opportunism.


Cost Estimation and Control for Flight Systems

Abstract: Good program management practices, cost analysis, cost estimation, and cost control for aerospace flight systems are interrelated and depend upon each other. The best cost control process cannot overcome poor design or poor systems trades that lead to the wrong approach. The project needs robust Technical, Schedule, Cost, Risk, and Cost Risk practices before it can incorporate adequate Cost Control. Cost analysis both precedes and follows cost estimation -- the two are closely coupled with each other and with Risk analysis. Parametric cost estimating relationships and computerized models are most often used. NASA has learned some valuable lessons in controlling cost problems, and recommends use of a summary Project Manager's checklist as shown here.


NASA Human Spaceflight Scenarios - Do All Our Models Still Say No?

Abstract: Historically, NASA human spaceflight planning has included healthy doses of life cycle cost analysis. Planners put projects and their cost estimates in a budget context. Estimated costs became expected budgets. Regardless, real budgets rarely matched expectations. So plans would come and go as NASA canceled projects. New projects would arise and the cycle would begin again. Repeatedly, NASA schedule and performance ambitions come up against costs growing at double-digit rates while budgets barely rise a couple of percent a year. Significant skepticism greets proposed NASA programs at birth, as cost estimates for new projects are traditionally very high, and worse, far off the mark for those carried forward. In this environment the current "capability driven framework" for NASA human spaceflight evolved, where long term life cycle cost analysis are even viewed as possibly counter-producti


Process-Based Cost Estimation for Ramjet/Scramjet Engines

Abstract: Process-based cost estimation plays a key role in effecting cultural change that integrates distributed science, technology and engineering teams to rapidly create innovative and affordable products. Working together, NASA Glenn Research Center and Boeing Canoga Park have developed a methodology of process-based cost estimation bridging the methodologies of high-level parametric models and detailed bottoms-up estimation. The NASA GRC/Boeing CP process-based cost model provides a probabilistic structure of layered cost drivers. High-level inputs characterize mission requirements, system performance, and relevant economic factors. Design alternatives are extracted from a standard, product-specific work breakdown structure to pre-load lower-level cost driver inputs and generate the cost-risk analysis. As product design progresses and matures the lower level more detailed cost drivers can be


Inference on Nonparametric Panel Data Models with Fixed Effects and Censored Dependent Variables


Panel Data and Fixed Effects


TSCI: Tools for Causal Inference with Possibly Invalid Instrumental Variables

David Carl
Corinne Emmenegger
Wei Yuan
Mengchu Zheng
Zijian Guo


Fixed and random effects models: making an informed choice

Andrew Bell
Malcolm Fairbrother
Kelvyn Jones

Abstract: This paper assesses the options available to researchers analysing multilevel (including longitudinal) data, with the aim of supporting good methodological decision-making. Given the confusion in the literature about the key properties of fixed and random effects (FE and RE) models, we present these models’ capabilities and limitations. We also discuss the within-between RE model, sometimes misleadingly labelled a ‘hybrid’ model, showing that it is the most general of the three, with all the strengths of the other two. As such, and because it allows for important extensions—notably random slopes—we argue it should be used (as a starting point at least) in all multilevel analyses. We develop the argument through simulations, evaluating how these models cope with some likely mis-specifications. These simulations reveal that (1) failing to include random slopes can generate anti-conservativ


The Budget and Appropriations Cycle


Impact of instrument schedule growth on mission cost and schedule growth for recent NASA missions

K. A. Kipp
S. C. Ringler
E. L. Chapman
C. W. Freaner


Public and Private Bureaucracies: A Transaction Cost Economics Perspective


Two-way fixed effects, the two-way mundlak regression, and difference-in-differences estimators

Abstract: Abstract I derive a result on the equivalence between the two-way fixed effects (TWFE) estimator and an estimator obtained from a pooled ordinary least squares regression that includes unit-specific time averages and time-period-specific cross-sectional averages—the two-way Mundlak (TWM) regression. The equivalence between TWFE and TWM implies that various estimators used for intervention analysis can be computed using pooled OLS that controls for time-constant treatment cohort indicators, time-period indicators, covariates, and interactions among them—allowing for considerable treatment effect heterogeneity. An extended version of TWFE (ETWFE) is equivalent to the POLS approach. I show that an imputation estimator, derived under no anticipation and parallel trends assumptions, is also equivalent to the POLS/ETWFE estimator. The equivalence among various estimators shows that average tre


Revisiting Event-Study Designs: Robust and Efficient Estimation

Kirill Borusyak
Xavier Jaravel
Jann Spiess

Abstract: Abstract We develop a framework for difference-in-differences designs with staggered treatment adoption and heterogeneous causal effects. We show that conventional regression-based estimators fail to provide unbiased estimates of relevant estimands absent strong restrictions on treatment-effect homogeneity. We then derive the efficient estimator addressing this challenge, which takes an intuitive “imputation” form when treatment-effect heterogeneity is unrestricted. We characterize the asymptotic behaviour of the estimator, propose tools for inference, and develop tests for identifying assumptions. Our method applies with time-varying controls, in triple-difference designs, and with certain non-binary treatments. We show the practical relevance of our results in a simulation study and an application. Studying the consumption response to tax rebates in the U.S., we find that the notional


On event studies and distributed‐lags in two‐way fixed effects models: Identification, equivalence, and generalization

Abstract: Summary We discuss three important properties of panel data event study designs. First, assuming constant treatment effects before and/or after some event time, also known as binning, is a natural restriction, which identifies dynamic treatment effects in the absence of never‐treated units. Second, event study designs with binned endpoints and distributed‐lag models are numerically identical. Third, classic dummy variable event study designs can be generalized to models that account for multiple treatments of different signs and varying intensities. We demonstrate the practical relevance of our methodological points in an application studying the effects of unemployment benefit duration on job search effort.


Comparing two-way fixed effects and new estimators for differences-in-differences: A simulation study and empirical example

Abstract: Background: Two-way fixed effects methods have been used to estimate effects of policies adopted in different places over time, but they can provide misleading results when effects are heterogeneous or dynamic, and alternate methods have been proposed. Methods: We compared methods for estimating the average treatment effect on the treated (ATT) under staggered adoption of policies, including two-way fixed effects, group-time ATT, cohort ATT, and target-trial approaches. We applied each method to assess the impact of Medicaid expansion on preterm birth using the National Center for Health Statistics’ birth records. We compared each estimator’s performance in a simulation parameterized to mimic the empirical example. We generated constant, heterogeneous, and dynamic effects and calculated bias, mean squared error, and confidence interval coverage of each estimator across 1000 iterations. R


Two-Way Fixed Effects and Differences-in-Differences with Heterogeneous Treatment Effects: A Survey

Clément de Chaisemartin
Xavier D’Haultfœuille

Abstract: Linear regressions with period and group fixed effects are widely used to estimate policies' effects: 26 of the 100 most cited papers published by the American Economic Review from 2015 to 2019 estimate such regressions. It has recently been shown that those regressions may produce misleading estimates, if the policy's effect is heterogeneous between groups or over time, as is often the case. This survey reviews a fast-growing literature that documents this issue, and that proposes alternative estimators robust to heterogeneous effects. We use those alternative estimators to revisit Wolfers (2006a).


Cliometrics: Past, Present, and Future

Oxford Research Encyclopedia of Economics and Finance

Abstract: Cliometrics is the application of economic theory and quantitative methods to the study of economic history. The methodology rose to favor in economics departments in the 1960s. It grew to dominate the discipline over the next two decades, culminating in the awarding of the 1993 Nobel Prize in Economics to two of its pioneers, Robert Fogel and Douglass North. Cliometrics has always had its share of critics, and some have blamed it for the diminished role that economic history has had in economics programs in the 21st century.


Structure and Performance: The Task of Economic History

Douglass C. North
Terry Anderson
Yoram Barzel
Tom Borcherding
Elisabeth Case
Steven N. S. Cheung
Victor P. Goldberg
Robert Higgs

Abstract: JHE CLIOMETRIC revolution in ecoknomic history wedded neoclassical economics and quantitative methods in order to describe and explain the performance of economies in the past.' Economic history gained in rigor and scientific pretension, but at the expense of exploring a much more fundamental set of questions about the evolving structure of economies that underlies performance.2 Cliometricians have turned their backs on a long tradition stretching back from Joseph Schumpeter to Karl Marx to Adam Smith. These scholars regarded economic history as essential because it added a dimension to economics. Its purpose was to analyze the parameters held constant by the economist. If economics is a theory of choice subject to specified constraints, a task of economic history was to theorize about those evolving constraints. The failure of economic historians to provide their colleagues with a histo


African Economic History in Africa

Abstract: This paper reviews the state of research in African economic history in tropical Africa, reaching a more pessimistic conclusion than Green and Nyambara. The subject has seen a renaissance in recent years but relatively few of the publications have come from authors based at universities between the Zambezi and the Sahara (the ‘sub-region’). This discrepancy is not new, except in degree. It is partly attributable to resource constraints. But it also reflects both intellectual priorities and the way disciplines are organized. Economics departments in the sub-region have shown little interest in history, especially recently; while history departments are often wary of both quantitative methods and economic theory, reflecting a frequently strong institutional divide between humanities and social sciences. Further, while it is true that economic historians in tropical Africa have been less en