Community matters: Heterogeneous impacts of a sanitation intervention.

Sanitation is at the heart of public health policies in most of the developing world, where around 85% of the population still lack access to safe sanitation. We study the effectiveness of a widely adopted participatory community-level information intervention aimed at improving sanitation. Results from a randomized controlled trial, implemented at scale in rural Nigeria, reveal stark heterogeneity in impacts: the intervention has immediate, strong and lasting effects on sanitation practices in less wealthy communities, realized through increased sanitation investments. In contrast, we find no evidence of impacts among wealthier communities. This suggests that a targeted implementation of CLTS may increase its effectiveness in improving sanitation. Our findings can be replicated in other contexts, using microdata from evaluations of similar interventions.