Here is an abstract of a recent policy research working paper by Hulman, Kolkma and Kraay:
Understanding the role of country versus project characteristics is important to large aid donors that implement many projects in a broad cross-section of countries. In a sample of 3,821 World Bank projects and 1,342 Asian Development Bank projects, project outcomes vary much more within countries than between countries. Country-level characteristics explain only 10–25 percent of project outcomes. Among macro country-level variables, country growth and the policy environment are significantly positively correlated with project outcomes. Among micro project-level variables, shorter project duration and the presence of additional financing are significantly correlated with better project outcomes. In addition, the track record of the project manager in delivering successful projects is highly significantly correlated with project outcomes. There are few significant differences between the two institutions in the relationship between these variables and project outcomes.
Main points related to WB and ADB projects:
- Country-level characteristics explain only 10-25% of project outcomes.
- Civil liberties and political freedom at the country level are negatively correlated with project outcomes.
- Projects that take longer to implement are less likely to be successful. Extending projects to attempt to achieve goals in spite of hitches during implementation may not always be successful.
- Difference between actual and initially-planned funding is positively correlated with project outcomes (projects that are not doing well need to be closed early).
- Track record of project manager (task team leader/project officer) is a very strong correlate of eventual project outcomes. [“Project manager turnover in WB projects is more likely to be driven by poor project performance, while in the ADB turnover is driven by other institutional factors. In this case, project outcomes would not be correlated with project manager turnover in the ADB.”]
- Significantly larger proportion of WB projects receive negative ratings in their first half when compared to ADB projects. [“An alternative explanation is that ADB project managers may be less willing to report problems early on. For example, ADB project managers may only be willing to admit to bad interim ratings if projects have only “small” or more “solvable” practical problems (such as procurement delays, etc.), and underreport more intractable problems related to ultimate outcomes. In other words, the positive observation that of those projects flagged as problems in the first half, the ADB has a better "turnaround rate," may not be entirely good news, to the extent that the projects being flagged as problems by project managers are ones where the problems are relatively easy to fix.”]
- Fewer ADB projects are flagged as possible problems than in the WB. [“This could possibly indicate lower candor on the part of ADB project managers, because overall project success rates are not so different between the two institutions.”]
- Detailed project designs and procurement packages need to be prepared prior to project implementation.