Low fertility: A review of the determinants

Working Paper No. 2

Publication Date: July 2019

Author: Elizabeth Wilkins

Classic demographic transition theory assumed that fertility would decline from high levels and stabilize at the replacement level of around 2.1 children per woman. Yet one-half of the global population now lives in a country where period fertility rates have fallen below 2.1 children per woman.

This report aims to review the theoretical and empirical evidence of the determinants of low fertility. 

This is part of a series of a UNFPA technical working paper series. 

Paper No. 1 in this series is: Policy responses to low fertility: How effective are they?

Related content


In the last three decades sub-replacement fertility has spread around the world. One half of the global population today lives in countries where the period Total Fertility Rate is below 2.1 births per woman.

Building on the INFORM framework and index, UNFPA developed a Population Risk and Resilience Assessment Framework, and a tool (DECA) to consolidate information essential for building resilience and sustainability in communities, and particularly among women and girls.
The demographic dividend is the accelerated development that can arise when a population has a relatively large proportion of working-age people coupled with effective human capital investment.