Survey data from eight Toposa villages were used to
examine the demographic effects of polygyny upon this
Southern Sudanese agro-pastoralist population. Direct age standardization
of fertility rates revealed lower fertility for
women in polygynous unions, as measured by maternal
age and marital duration. Indirect techniques of mortality
estimation indicated higher childhood mortality for offspring
of polygynous marriages. The underlying rationale
for these demographic differentials is attributed to Toposa
social structure, including the economic value of women,
gerontocracy and residential patterns.