Mosquito-Borne Disease and Newborn Health

While mosquito-borne diseases are currently most prevalent in mid-latitude countries, rising global temperatures are expanding their range. This paper investigates whether one such disease, dengue, harms newborns. Health at birth has been shown to impact economic outcomes throughout life. The empirical design exploits variation in lagged dengue rates in a town's closest neighbors and largest trading partner. The underlying source of exogeneity in this variation comes from two components: the uneven allocation, across municipalities, of funding to combat the mosquito vector and random weather patterns. Past disease rates in adjacent areas are used as instruments for the dengue rate in a newborn's municipality of residence. Using administrative individual data from birth records in Brazil, I find that a one standard deviation increase in the incidence of dengue in the third trimester of gestation reduces birth weight by 0.75 grams on average. The effect is more pronounced for baby girls and for children of more educated mothers. Moreover, there seems to exist a positive effect of dengue exposure during the early stages of gestation among children of mothers that do not receive scheduled prenatal care. The likely channel is that these women access pregnancy resources as a consequence of seeking medical treatment for dengue.