Does variation in how religious festivals are celebrated have economic consequences? We study the economic impacts of the timing of Catholic patron saint day festivals in Mexico. For causal identification, we exploit cross-locality variation in festival dates and in the timing of agricultural seasons. We estimate the impact of "agriculturally-coinciding" festivals (those coinciding with peak planting or harvest months) on long-run economic development of localities. Agriculturally-coinciding festivals lead to lower household income and worse development outcomes overall. These negative effects are likely due to lower agricultural productivity, which inhibits structural transformation out of agriculture. Agriculturally-coinciding festivals may nonetheless persist because they also lead to higher religiosity and social capital.

Between 1921 and 1956, French colonial governments organized medical campaigns to treat and prevent sleeping sickness. Villagers were forcibly examined and injected with medications with severe, sometimes fatal, side effects. We digitized 30 years of archival records to document the locations of campaign visits at a granular geographic level for five central African countries. We find that greater campaign exposure reduces vaccination rates and trust in medicine, as measured by willingness to consent to a blood test. We examine relevance for present-day health initiatives; World Bank projects in the health sector are less successful in areas with greater exposure.