Son preference has persisted in the face of sweeping economic and social changes in the countries studied here. We attribute this persistence to their similar family systems, which generate strong disincentives to raise daughters – whether or not their marriages require dowries – while valuing adult women's contributions to the household. Urbanisation, female education and employment can only slowly change these incentives without more direct efforts by the state and civil society to increase the flexibility of the kinship system such that daughters and sons can be perceived as being more equally valuable. Much can be done to accelerate this process through social movements, legislation and the mass media.