JORGE H. BRAVO
Transition theory has pervaded demographic thinking since early in this century, and in spite of some limitations as an explanatory model of observed demographic trends, continues to provide a basis for broad generalizations about fertility change. Some of its well-known main elements--such as the emphasis on the global process of modernization, the consequent improvements in survival, female employment opportunities, and other changes leading to the increase in the relative cost of children--are also incorporated, more formally, in modern micro-economic models.1 Critical assessments of transition theory, based on evidence from some recent empirical studies of fertility declines (much of it coming from the findings of the Princeton European Fertility and the WFS projects), have expressed doubts about the usefulness of this approach. The absence of clear, consistent associations between fertility declines, mortality and other 'modernization' variables, the verification of multiple exceptions and apparent asynchronies between the changes in socio-economic variables and fertility, constitute some of the evidence cited for this line of argument.2 Ideational changes, having more to do with the social diffusion of low fertility norms and behaviour, are given centrality over individual economic calculus.
To be sure, this alternative type of approach to interpreting fertility transitions is not completely novel. According to Gösta Carlsson ( 1966: 149) transition theory had, by the 1960s, lost its dominant role to the 'innovation' approach, which (according to the same author) can be characterized by the following three elements: (1) the consideration of fertility control as a recent invention in human culture; (2) the emphasis on the importance of the spread of knowledge about contraception; and (3) the assumption of lags and gradients in the spread of skills____________________