Page 131 - IJPS-11-3

International Journal of

Population Studies

RESEARCH ARTICLE
Using discrete choice modeling to understand

the drivers of reproductive delay in the
United Kingdom

Paula Sheppard*

School of Anthropology and Museum Ethnography, University of Oxford, Oxford, United Kingdom

Abstract

The ideal family size in the UK is, on average, two children. However, there is a fertility
gap, the difference between wanted and achieved family size, of around one in three
children, which is largely caused by extended delays to reproduction. Standard
quantitative methods used to identify what causes these delays have limitations,
often relying on macro-level data which conveys little about individual needs, or
applying longitudinal methods that produce outdated results because only once
people have completed their reproductive years is it possible to infer which life-
course factors led to later-age childbearing. This study is the first to overcome these
challenges by applying a discrete choice experiment to reveal the barriers that people
*Corresponding author: are facing right now. This innovative methodology allows the estimation of the relative
Paula Sheppard importance of the barriers and the distance between them measured in months of
(paula.sheppard@anthro.ox.ac.uk) reproductive delay. Among other things, the results show that for men and women,
Citation: Sheppard, P. (2025). partner support was more important than finances or housing, although support
Using discrete choice modeling means different things depending on the level of education with more educated
to understand the drivers of
reproductive delay in the United women prioritizing hands-on fathers and household gender equality, whereas less-
Kingdom. International Journal of educated women strongly desired stable partnerships. Men favored partner readiness
Population Studies, 11(3): 125-137. and neighborhood quality. These, and the other findings shown here, provide detailed
https://doi.org/10.36922/ijps.3600
insight into the contemporary causes of delayed fertility in the UK.
Received: May 7, 2024
1st revised: May 15, 2024 Keywords: Fertility gap; Reproductive delay; Reproductive decision-making; Discrete
2nd revised: August 14, 2024 choice; Gender equality; Family size
Accepted: October 12, 2024
Published online: November 6,
2024 1. Introduction
Copyright: © 2024 Author(s).
This is an Open-Access article In the United Kingdom, fertility is low with only 1.6 births per woman on average in
distributed under the terms of the 2020 (The World Bank, 2022), which is half a birth lower than the 2.1 needed to meet the
Creative Commons Attribution population replacement rate. Although people wish to have small families, there is also
License, permitting distribution,
and reproduction in any medium, a gap between the family size people say they want, and the number of children many
provided the original work is then go on to have. This is known as the “fertility gap” and in the UK the gap measures
properly cited. around one-third of a child; people express a general preference for two-child families
Publisher’s Note: AccScience (Smallwood & Jeffries, 2003). The fertility gap is primarily driven by the postponement
Publishing remains neutral with of childbearing (Berrington, 2004; Morgan & Rackin, 2010); in 2020, the age at first
regard to jurisdictional claims in
published maps and institutional birth was 29.1 years for women (Clark, 2022). The increase in rates of late parenthood is
affiliations. also striking; in 2016, 22.3% of births were to mothers over age 35 compared with just

Volume 11 Issue 3 (2025) 125 https://doi.org/10.36922/ijps.3600