In a recent randomized experiment we found mean returns to capital of between 5 and 6 percent per month in Sri Lankan microenterprises, much higher than market interest rates. But returns were found to be much higher among men than among women, and indeed were not different from zero for women....

Small and informal firms account for a large share of employment in developing countries. The rapid expansion of microfinance services is based on the belief that these firms have productive investment opportunities and can enjoy high returns to capital if given the opportunity. However,...