In the past decade economists have begun to carry out randomised field trials in social settings to examine effectiveness of developmental projects that ranged from micro-financing to vaccination in a school setting. There is strong recognition among economists that experimental design in a...

This article details the design of an impact evaluation of the Millennium Villages Project in Northern Ghana. The evaluation is particularly challenging because the intervention cannot be randomised; it is clustered in a group of homogeneous communities and likely to generate spill-over effects....