Estimating age-specific fertility rate in the World Population Prospects: A Bayesian modelling approach

Abstract

As part of its work in revising population estimates and projections for the biennial publication of the World Population Prospects (WPP), the United Nations Population Division produces age-specific fertility estimates for all countries and areas of the world, starting from 1950 up to today. These estimates are based on data from several reference data sources, such as civil registration and vital statistics systems, sample registration systems, surveys, national estimates and population censuses, and calculated using standard demographic techniques and approaches. Available estimates are often affected by biases and inconsistencies that need to be examined and considered while producing the annual series of age-specific fertility estimates. This technical paper details the Bayesian hierarchical model (BHM) that the Population Division developed to estimate the levels and trends in age-specific fertility rates (ASFR) for all countries and areas since 1950. The model uses an extensive database of fertility data from various data sources maintained by the Population Division. The BHM allows sharing of information across countries and periods to inform annual estimates for the countries and periods with sparse, biased or non-available data. The information included in World Population Prospects is used widely by the United Nations system, academia and civil society, among others, including for monitoring several indicators of the Sustainable Development Goals. The age-specific fertility estimates from the World Population Prospects are used to monitor the global and regional trends of the Sustainable Development Goal 3.7.2 Adolescent birth rate (aged 10–14 years; aged 15–19 years) per 1,000 women in that age group.

Fengqing Chao

Assistant Professor of Computational Social Science

My research interests include statistical demography, global health, Bayesian modeling, and time series analysis.