The adoption of means of regulating fertility depends upon costs of fertility regulation which includes subjective (psychic) costs and objective costs such as money required learning about and using a specific method.

What are the considerations which influence the adoption of fertility control? Search through sociological literature reveals that motivation, attitudes and access are the three important factors influencing adoption of fertility control.

It can be stated that in general the probability of adopting control is higher when the degree of motivation if greater and the costs of fertility regulation are lower.

It can be recalled from earlier discussions that there has been a shift from high fertility to low fertility and that the fertility shift has accompanied the process of socio-economic development. However, it should be mentioned here that the specific links between the two are not clear.


Multivariate Regression on Basic Determinants

Richard A. Easterlin, “Modernization and Fertility: A Critical Appraisal,” in RA. Bulatao and R.D. Lee (Eds.), Determinants of Fertility in Developing Countries, Vol. 2, New York: Academic Press, 1983, pp. 562-586.

A common approach in identifying the specific links between the processes of socio-economic development (modernization) is to regress the fertility variable on various indicators of socio-economic development, and other cultural factors.

The recent development of the intermediate or proximate varieties introduced an intervening stage into this analysis.


It is now recognised that fertility is directly affected by a set of “intermediate or proximate variables” and any socio-economic, political or environmental factor affects fertility behaviour only through these variables.

It is further shown in Panel II of Figure 9.2 that an important subset of the proximate variables or determinants, namely, the deliberate fertility control variable is affected by “intervening variables” supply, demand and fertility regulation costs.

Various development variables directly influence supply, demand and fertility regulation costs. These factors, in turn, influence the use of deliberate control and finally the latter jointly with other proximate variables determine observed fertility.

In the following section the analysis is extended to show how demand for children, potential supply and costs of fertility regulation influence the use of fertility control measures as socio-economic conditions advance.


The process of socio-economic development is shown as a one-dimensional process corresponding a movement towards the right, along the horizontal axis. Supply and demand measured according to surviving children per married.