Introduction: Demographers’ theoretical explanations for fertility decline have been based for decades on an assumption that couples make family size decisions influenced by a changing balance between costs and benefits of childbearing, resulting in parents’ reduced demand for children. It has been widely assumed that these decisions are based on changes in social or economic factors, such as increased education, wealth or economic opportunities, or urbanisation, or other related factors in their lives. However, a number of situations in developing countries have been documented showing that contraceptive prevalence rose more rapidly than such theories could account for. In some instances desired family size changed when contraception became available, and in others women who said they did not want to use contraception adopted a method when the option to use it arrived. We have reviewed the cases of this kind that are published in the demographic literature, and we offer a plausible explanation grounded in research on consumer behaviour.
Published in J Fam Plann Reprod Health Care. 2006 Oct;32(4):241-4.