Fertility and polygyny: Experimental evidence from Burkina Faso

Decision-making about fertility differs between monogamous and polygynous households. In an experiment in Burkina Faso that gives women access to free contraceptives, either alone or with their husband, involving the husband decreases contraceptive use among monogamous women, but not among polygynous women. Where there is co-wife rivalry, it increases contraceptive use. This is consistent with a model where monogamous women have a stronger preference for contraceptives than their husband, while this preference difference is smaller or even reversed among polygynous households due to co-wife competition around fertility.