The sibsize revolution in an international context: Declining social disparities in the number of siblings in 26 countries

Patrick PrÄg, Seongsoo Choi, Christiaan Monden

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8 Citations (Scopus)


BACKGROUND One's number of siblings is an important determinant of many life outcomes, such as educational attainment. In the last century the United States has experienced a ‘sibsize revolution', in which sibship sizes declined, and which led to a convergence in family circumstances for children. Did this happen in other countries as well? OBJECTIVE This study examines the development of sibship size and social disparities in sibship size in low-fertility countries across the 20th century. METHODS We analyze sibship size data collected from 111 nationally representative surveys conducted in 26 low-fertility countries across the 20th century. RESULTS Average sibship sizes have declined in virtually all countries. Average sibship sizes are socially stratified, with smaller sibship sizes among higher-educated parents. This social disparity in sibship size has declined over time, indicating convergence in most countries. This convergence applies to large families, but not to only-child families. CONTRIBUTION Siblings are an understudied phenomenon in family demography, despite their growing importance in a time of increasingly complex family structures. Given the significance of sibship size for children's educational outcomes and overall life chances, decreasing social disparities in sibship size suggest greater equality in the intergenerational transmission of advantage.

Original languageEnglish
Pages (from-to)461-500
Number of pages40
JournalDemographic Research
Issue number17
Publication statusPublished - 2020 Aug

Bibliographical note

Funding Information:
6. Acknowledgments Previous versions of this study were presented at the annual meeting of the Population Association of America in Denver 2018 and the German Society for Demography conference in Cologne 2018. We thank discussants at these meetings as well as the anonymous reviewers of Demographic Research for constructive comments and Riley Taiji, Manting Chen, and Jung In for research assistance. The data used in this study is publicly available (Monden et al. 2018) and replication materials can be found online (PrÄg, Choi, and Monden 2020). This study has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under grant agreement no. 681546 (FAMSIZEMATTERS).

All Science Journal Classification (ASJC) codes

  • Demography


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