Cicadian Rhythm: Insecticides, Infant Health and Long-term Outcomes

This paper utilizes a peculiar ecological phenomenon, the mass emergence of cicadas in 13 and 17-year cycles, to identify the impact of pesticides on human health and long-term development. I rely on the fact that cicadas only damage woody plants (e.g., apple trees), through egg laying in branches and subsequent nymph-feeding on roots—and not agricultural row crops. Using the natural temporal and geographic variation of cicada emergence, I show that a sharp increase in insecticides coincides with cicada emergence in places with high tree crop production. This is followed by higher subsequent-year infant mortality and adverse health impacts. Looking at longterm eects, I find evidence of lower elementary test scores and then higher dropout rates among exposed cohorts. This paper supports the conclusion that moderate levels of environmental pollution, not just extreme exposure, can aect human health and development. J