Marriage in the time of the HIV/AIDS epidemic

We examine whether the emergence of the HIV/AIDS epidemic—a major non-monetary health shock—affected marriage formation in Brazil during its early years (1982–1991). Using a two-period non-cooperative model, we show that as the likelihood of encountering an infected partner rose, the perceived benefits of marriage increased. Combining this theoretical framework with municipal-level data from population censuses and HIV/AIDS case reports, we estimate the impact of the epidemic on the marital surplus and on individual marriage probabilities. To address endogeneity, we exploit the spatial diffusion of the epidemic, using the geodetic distance to the nearest municipality with a newly reported HIV/AIDS case as an instrument for local exposure. Our findings indicate that HIV/AIDS heightened the value of marriage and increased marriage rates during the epidemic’s onset, consistent with individuals seeking stability and protection under elevated mortality risk. These results highlight how a large-scale health crisis can alter family-formation behavior in the absence of effective treatment.