Two mechanisms have been proposed to explain sex selection in India: son preference, in which parents desire a male heir, and daughter aversion, in which dowry payments make parents worse off with girls. Our model incorporates both mechanisms, providing microfoundations, based on the organization of the marriage institution, for daughter aversion. Marital matching, sex selection, and dowries are jointly determined in the model, whose implications are tested on a representative sample of rural households. Simulations of the model indicate that existing policies targeting daughter aversion might exacerbate the problem, while identifying other policies that could be effective. (JEL D31, G51, J12, J16, O12, O18, Z13)