Abstract:A brisk building boom of hydropower mega-dams is underway from China to Brazil. Whether benefits of new dams will outweigh costs remains unresolved despite contentious debates. We investigate this question with the "outside view" or "reference class forecasting" based on literature on decision-making under uncertainty in psychology. We find overwhelming evidence that budgets are systematically biased below actual costs of large hydropower dams-excluding inflation, substantial debt servicing, environmental, and social costs. Using the largest and most reliable reference data of its kind and multilevel statistical techniques applied to large dams for the first time, we were successful in fitting parsimonious models to predict cost and schedule overruns. The outside view suggests that in most

China's three-decade infrastructure investment boom shows few signs of abating. Is China's economic growth a consequence of its purposeful investment? Is China a prodigy in delivering infrastructure from which rich democracies could learn? The prevalent view in economics literature and policies derived from it is that a high level of infrastructure investment is a precursor to economic growth. China is especially held up as a model to emulate. Politicians in rich democracies display awe and envy of the scale of infrastructure Chinese leaders are able to build. Based on the largest dataset of its kind, this paper punctures the twin myths that (i) infrastructure creates economic value, and that (ii) China has a distinct advantage in its delivery. Far from being an engine of economic growth, the typical infrastructure investment fails to deliver a positive risk-adjusted return. Moreover, China's track record in delivering infrastructure is no better than that of rich democracies. Investing in unproductive projects results initially in a boom, as long as construction is ongoing, followed by a bust, when forecasted benefits fail to materialize and projects therefore become a drag on the economy. Where investments are debt-financed, overinvesting in unproductive projects results in the build-up of debt, monetary expansion, instability in financial markets, and economic fragility, exactly as we see in China today. We conclude that poorly managed infrastructure investments are a main explanation of surfacing economic and financial problems in China. We predict that, unless China shifts to a lower level of higher-quality infrastructure investments, the country is headed for an infrastructure-led national financial and economic crisis, which is likely also to be a crisis for the international economy. China's infrastructure investment model is not one to follow for other countries but one to avoid.

No abstract

This paper gives an overview of good and bad practice for understanding and curbing cost overrun in large capital investment projects, with a critique of Love and Ahiaga-Dagbui (2018) as point of departure. Good practice entails: (a) Consistent definition and measurement of overrun; in contrast to mixing inconsistent baselines, price levels, etc. (b) Data collection that includes all valid and reliable data; as opposed to including idiosyncratically sampled data, data with removed outliers, non-valid data from consultancies, etc. (c) Recognition that cost overrun is systemically fat-tailed; in contrast to understanding overrun in terms of error and randomness. (d) Acknowledgment that the root cause of cost overrun is behavioral bias; in contrast to explanations in terms of scope changes, complexity, etc. (e) De-biasing cost estimates with reference class forecasting or similar methods based in behavioral science; as opposed to conventional methods of estimation, with their century-long track record of inaccuracy and systemic bias. Bad practice is characterized by violating at least one of these five points. Love and Ahiaga-Dagbui violate all five. In so doing, they produce an exceptionally useful and comprehensive catalog of the many pitfalls that exist, and must be avoided, for properly understanding and curbing cost overrun. Five Key Questions about Cost Overrun Cost overrun in large capital investment projects can be hugely damaging, incurring outsize losses on investors and tax payers, compromising chief executives and their organizations, and even leading to bankruptcy (Flyvbjerg et al. 2009, Flyvbjerg and Budzier 2011). Accordingly, cost overrun receives substantial attention in both the professional literature and popular media. Yet it is not always clear how cost overrun is defined, why it happens, and how to best 1 All authors have co-authored or authored publications based on the data, theories, and methods commented on by Love and Ahiaga-Dagbui (2018).

No abstract