We bound the distribution of treatment effects under plausible and testable assumptions on the joint distribution of potential outcomes, namely that potential outcomes are mutually stochastically increasing. We show how to test the empirical restrictions implied by those assumptions. The...

In most of Sub-Saharan Africa, agricultural extension models have become more decentralized and participatory and thus rely on effective farmer-to-farmer learning, while increasingly including nontraditional forms of education. At the same time, agricultural technologies become more complex and...