Constructing appropriate counterfactual scenarios is an ongoing challenge for impact assessment of agricultural research. Using farm-level survey data from Honduras, this paper adapts the Heckman two-step procedure to construct the counterfactual to resistant variety (RV) bean yields by...

In every region of the world, the intensification of crop-based agriculture has been associated with a sharp increase in the use of chemical fertilizer. Given the generally low levels of fertilizer use in Africa, there can be little doubt that fertilizer use must increase in Africa if the region...