The Measurement of Wanted Fertility

Abstract

ALTHOUGH POPULATION SPECIALISTS HAVE SUCCESSFULLY DEVISED procedures for estimating standard demographic indicators (e.g., levels of fertility and mortality), they have been notably unsuccessful in reaching agreement on the most appropriate way to measure wanted fertility. The lack of consensus on this issue has hampered progress in the validation of competing theories of the fertility transition because measures of family size preferences or wanted fertility are often key factors in those theories. The absence of commonly agreed-upon summary indicators of preferred fertility is not due to a lack of data. In fact, virtually all fertility surveys conducted in recent decades have included at least one and, more often, a number of questions on fertility preferences. For example, the World Fertility Survey (WFS), conducted in 41 developing countries, included questions on desired family size, whether more children were wanted, the wanted status of the most recent birth or pregnancy, and the number of additional children wanted. A number of direct and indirect indicators of desired family size or wanted fertility can be derived from responses to these questions oIn reproductive preferences. A review of the extensive literature on this subject is beyond the scope of this article (but see Lightbourne and MacDonald, 1982; Lightbourne, 1985a; and United Nations, 1987 for further details). The main problem is the often large differences between various existing summary indicators of preferred fertility. The reasons for these differences are not always clear, and, as a consequence, analysts who want to use preference indicators have insufficient guidance as to which of the wide variety of available indicators best suits their purposes. The main objective of the present analysis is to obtain a new and more accurate measure of the wanted and unwanted components of the total fertility rate (TFR), which is the most widely used indicator of overall fertility. Births are considered unwanted if they occur after a woman has reached the point at which she does not wish to continue childbearing. All other births, including those that are mistimed, will be considered wanted.' Es-