We study the adoption of a rainwater harvesting technique – demi-lunes – in Niger. Like many “environmental” technologies, demi-lunes require an upfront investment in exchange for long-run benefits, which agronomists estimate to be substantial. We implement a cluster randomized control trial in 180 villages with treatments designed to relax informational, credit and labor constraints. Relative to a pure control group, training increases the probability of adoption by 90 percentage points. Combining training with cash transfers, either unconditional or conditioned on adoption outcomes, has no additional effect on the extensive margin of adoption, but increases the intensity of adoption by 35-50 percent relative to training alone. We also observe increases in labor investment and agricultural output, consistent with agronomic descriptions of the costs and benefits of adoption, as well as other measures of household well-being. Despite the impacts on labor costs, we find no evidence of significant general equilibrium effects on wage rates, in part because the optimal window coincides with the slack agricultural season in Niger. We also find high rates of continued use the technology two years’ later. We use the pattern of results and our nested experimental design to investigate the mechanisms underlying our findings, and their implications for policy. In contrast to prior literature, information appears to be a primary constraint to adoption in our setting.

Written with Kelsey Jack