The emergence of birth limitation as a new stage in the fertility transition in sub-Saharan Africa

Abstract

BACKGROUND The fertility transition started later in sub-Saharan Africa than in other regions of the world. Moreover, the average number of children per woman declined more slowly there, owing to a distinct mechanism of fertility reduction. It has been argued that the fertility decline in sub-Saharan Africa proceeded through an increase in birth intervals rather than by a limitation of the number of births. OBJECTIVE We analyze the fertility transitions in 29 countries to determine which mechanism women resort to in order to reduce their number of children. METHODS Using multiple sample surveys, we estimate and cross-validate trends in parity progression ratios and birth intervals. We identify sub-regional regularities and vanguard trends in the interplay between the dynamics of the lengthening of birth intervals and birth limitation over the period 1962-2012. RESULTS While initial fertility declines were driven by a lengthening of birth intervals at all parities, we observe a recent onset of birth limitation in regions and countries that are most advanced in the fertility transition. CONCLUSIONS The experience of sub-Saharan Africa shows that if all parities contribute to the fertility transition from the outset, the main drivers of the fertility decline switch from a lengthening of birth intervals to a limitation of family size when the average fertility reaches about five children per woman. CONTRIBUTION Our findings point to the emergence of birth limitation as a new stage in the fertility transition in sub-Saharan Africa. These results have implications for future fertility declines in sub-Saharan Africa.