The Supply-Demand Framework for the Determinants of Fertility: An Alternative Implementation

Easterlin's supply-demand framework for the determinants of fertility is widely accepted because it has brought conceptual clarity to the study of factors that underlie the childbearing process. This model has not, however, succeeded in quantifying the fertility determinants in a convenient and generally accepted manner. The variant of Easterlin's model presented in this paper aims to remove obstacles to empirical implementation. In addition to quantifying the supply and demand factors, a new variable, the degree of preference implementation, is introduced to measure the role of costs and benefits of fertility regulation. Applications of this alternative method, to data from surveys in 18 less developed countries indicate that recent declines in fertility have largely been due to reductions in the demand for births, and to increases in preference implementation. Changes in the supply of births appear to have played only a minor role.