Relationships between Marriage and Fertility Transitions in Sub-Saharan Africa

Takudzwa Sayi, Princeton University

Marriage patterns have been changing in sub-Saharan Africa, but changes in the relationship between marriage and fertility are not well established. As populations deviate from natural fertility, the importance of changing marriage rates for aggregate fertility trends is expected to decline (Bongaarts 1987), as women begin to exert deliberate controls on their reproduction. I explore this hypothesis using DHS data to decompose GFR changes between consecutive surveys into effects of changes in marriage rates, marital fertility, nonmarital fertility, and age distribution. Results suggest that the relative effects of changing marriage rates increased with increasing fertility levels: they were smallest in Namibia and Zimbabwe, larger in Kenya and Rwanda, and highest in Benin and Nigeria. Among adolescents, decreasing marriage rates depressed fertility, but other factors were important for fertility trends. Understanding these effects is important for identifying target populations for fertility interventions in different countries.