Mosquitoes,birth rates and regional spillovers: Evidence from the Zika epidemic in Brazil

This paper investigates the impact of the incidence of the Zika virus on birth rates in Brazil. We estimated a difference-in-differences model that explicitly considers the spatial interaction of virus incidence, measuring its impact on the affected municipalities and their neighbours—not directly affected. Our results show that directly affected municipalities experienced a 1.7% decrease in birth rates in 2016 and 2.5% in 2017, while municipalities close to those affected—but not directly affected—showed reductions of 1.2% and 2.1% for the same periods. Moreover, the evidence shows that the effect was not guided by biological effects and was concentrated among younger women.