Over the last two decades, the literature on comparative development has moved from country-level to within-country analyses. The questions asked have expanded, as economists have used satellite images of light density at night and other big spatial data to proxy for development at the desired...

This paper makes the case for greater use of randomized experiments "at scale." We review various critiques of experimental program evaluation in developing countries, and discuss how experimenting at scale along three specific dimensions - the size of the sampling frame, the number of units...