Learning in social networks and contraceptive choice.

A puzzling observation in the diffusion of modern fertility control is the persistent diversity in contraceptive practices across communities or social strata. I propose a model of "learning in social networks" to explain this diversity with the random dynamics of word-of-mouth communication. Women are uncertain about the merits of modern contraception and estimate the different qualities of available method based on imprecise information from network partners. Their contraceptive choices are determined by this estimate and by private knowledge about one's personal characteristics. This process of social learning leads to path-dependent adoption of fertility control within, and diversity in contraceptive practices across villages or social strata.