Demographic transition in ecological focus.

Demographic transition theory posits that modernization, particularly in the form of urban industrialism, fundamentally alters the environmental context surrounding fertility decision-making, thereby reducing the advantages of having children. While fertility research has either questioned the link between modernization and fertility or attempted to provide the intervening links between the two, there has been little theoretical or empirical refinement of the macrosocial/contextual principles of the theory. The authors argue that human ecology and evolutionary theory can help respecify and revitalize demographic transition theory. The authors' respecification produces a more logical account of fertility decline that emphasizes the influences of service economies and the social adaptations attendant on ethnic heterogeneity and preindustrial social complexity. Analyses of changes in total fertility rates in approximately 60 less developed countries suggest: 1) general (if partially ambiguous) support for demographic transition theory, 2) confirmation of a robust effect of service-sector dominance on fertility, and 3) the importance of ethnic homogeneity and preindustrial social complexity to demographic transition. (Author's)