In this introductory essay to the special issue, we introduce a new dataset of foreign assistance, AidData, that covers more bilateral and multilateral donors and more types of aid than existing datasets while also improving project-level information about the purposes and activities funded by...

This article seeks to explain why the World Bank's environmental performance is so uneven despite numerous reform efforts. I argue that a principal-agent model offers a potentially powerful tool for analyzing gaps between the mandates and performance of international organizations (IOs) such as...