The Proximate Determinants during the Fertility Transition

Fertility has declined very markedly in the majority of developing countries over the past thirty to forty years, and it continues to decline almost everywhere. As a result, fertility has reached very low levels in many countries. In addition, currently more than 40 per cent of the world’s population lives in countries with total fertility levels lower than 2.1 children per woman, the level that, under conditions of low mortality, assures the long-term replacement of the population. The increasing number of countries with below-replacement fertility raised the question as to what are the prospects for the future fertility levels of countries with “intermediate” fertility today, that is, those where fertility is still above replacement level but is below five children per woman. Will their fertility, which continues to decline, inevitably reach levels below replacement, leading the whole world to below-replacement fertility? Or will their fertility follow sufficiently diverse paths determined by factors which remain to be identified?