How Many Children Does It Take to Replace Their Parents? Variation in Replacement Fertility as an Indicator of Child Survival and Gender Status

Robert Engelman, Population Action International
Elizabeth Leahy, Population Action International

Replacement fertility is a key demographic concept often misconstrued as a constant 2.1 children per woman. Actually it varies by population and over time, from as low as 2.06 children per woman to well over 3. High replacement fertility mostly reflects low survival of female infants (i.e., future childbearers) to their own reproductive age. High sex ratios at birth can also raise replacement fertility values somewhat. Replacement fertility is generally perceived as relevant only to population stationarity or decline. Its variation can, however, illuminate child and adolescent survival and some aspects of female status when its components are disaggregated. Those who study and work on population can clarify for policymakers the importance of tracking and publicizing variation and change in replacement fertility rates. This concept can then evolve from a hypothetical "target" on which total fertility rates should converge to an indicator of young people's health and female well-being.