INTERACTION DIFFUSION AND FERTILITY TRANSITION IN COSTA-RICA

A long-standing concern of sociologists is the contribution of diffusi on processes to social change. This article considers the contribution of social interaction diffusion to the fertility transition in Costa Rica, focusing on person-to-person contagion. Several prominent featur es of the Costa Rican transition suggest the existence of interaction diffusion effects, notably its pervasiveness toward all socioeconomic strata and the lack of evidence of a downward shift in family size pre ferences. Maps of the timing of fertility transition show an ordered s patial pattern suggestive of contagion between neighboring areas. A dy namic regression model estimated from pooled time series data for 100 counties reveals inter- and within-county diffusion effects on birth c ontrol adoption net of socioeconomic and family-planning program effec ts.