It’s Raining Babies? Flooding and Fertility Choices in Bangladesh

A growing demographic literature examines the impacts of climatic variability and environmental shocks on human population dynamics, focusing largely on migration, morbidity, and mortality. Considerably less is known about the effects of environmental changes on fertility despite plausible theoretical and empirical reasons to expect such impacts. We contribute new evidence to this emerging literature by examining the relationship between exposure to flooding and fertility in Bangladesh. We link birth records (n = 617,081 person-years) from the Demographic and Health Survey (DHS) with satellite-derived measures of flooding from 2001 through 2018 and fit regression models to measure the effects of flood exposures on the probability of live births in subsequent years. To explore hypothesized causal pathways, we also construct panels of women’s entry into first marriage (n = 52,293 person-years) and mortality among under-5 children (n = 331,153 person-years), and fit comparable regression models of these fertility correlates. Overall, flooding has highly uneven effects on fertility across the target population. We detect statistically and substantively meaningful flood-related increases in childbearing among less-educated and higher-parity women; but find evidence of flood-related declines in fertility among childless women and those in urban areas. Among all populations, these flood effects operate with a two-year lag. The analyses suggest that flood-related declines in marriage among urban women may explain reductions in fertility among this population. However, they otherwise provide little systematic evidence that marriage and child mortality mediate the links between flood exposures and fertility.