The effect of contraception on fertility: Is sub-Saharan Africa different?

Abstract

BACKGROUND Cross-sectional analyses of the relationship between contraceptive prevalence and the total fertility rate of developing countries show the expected strong negative correlation. However, this correlation is much weaker in sub-Saharan Africa than in the developing world as a whole. OBJECTIVE This paper aims to explain the unexpected weak effect of contraceptive use on fertility in sub-Saharan African countries by using different regression models to obtain unbiased effects. METHOD Using DHS survey data from 40 developing countries, the analysis consists of three steps: 1) examine the conventional cross-sectional TFR-CPR relationship by region at the time of the latest available surveys; 2) remove known technical flaws in the comparisons of fertility and contraceptive prevalence; and 3) analyze multiple observations of TFR and CPR per country using pooled OLS and fixed effect regressions. RESULTS The conventional cross-sectional analyses produce biased results, in part because technical factors, in particular postpartum overlap, create a downward bias in the effect of contraceptive prevalence on fertility in sub-Saharan Africa. In addition, and more importantly, the cross-sectional regression OLS parameters have a bias due to confounding country fixed effects. Technical adjustments and the use of fixed-effect models remove these biases. CONCLUSION A rise in contraceptive prevalence among fecund women has the same average effect on fertility in sub-Saharan Africa as in other regions of the developing world.