Working paper · 2026
Learning at Scale: Infrastructure, Aid Effectiveness, and World Bank Performance
Drawing on economic rates of return from roughly 2,500 World Bank financed infrastructure projects, the paper finds an average return near 24 percent. Those returns run systematically higher in countries with weak governance, where strong project performance adds about 12 percentage points to the average return.
Somik Lall, Xinyi Su, Maria Vagliasindi. World Bank Policy Research Working Paper 11412, 2026.
The policy line
Well-run infrastructure projects deliver their largest returns precisely where governance is weakest, so project quality is a central lever for development.
Summary
Drawing on economic rates of return from roughly 2,500 World Bank financed infrastructure projects, the paper finds an average return near 24 percent. Those returns run systematically higher in countries with weak governance, where strong project performance adds about 12 percentage points to the average return.
The full text is available at the publisher.
