Assortative Mating by Sibship Position in Japan: An Evaluation of Low Fertility, Family Norms, and Declining First Marriage Rates

Fumiya Uchikoshi , University of Wisconsin-Madison
James M M. Raymo, University of Wisconsin-Madison
Shohei Yoda, National Institute of Population and Social Security Research

Studies argued that changes in the supply of key characteristics within the marriage market can result in marriage market mismatches. This paper focuses on an understudied, but potentially important, dimension of assortative mating in low-fertility countries – sibship position. In low-fertility populations, the prevalence of only-children and eldest children, and single-sex sibships is higher than higher-fertility settings. The changes in sibship composition are particularly important in East Asian societies such as Japan where eldest sons have long been expected to maintain the family lineage and their wives are more likely to coreside with parents-in-law. This study provides new and valuable insights into how demographic change, in combination with “traditional” family norms and expectations, affects marriage behavior. Using the National Fertility Survey, we find the marriage between women without brothers with eldest sons is less likely to occur, particularly for the eldest daughters, and the prevalence dramatically declines in recent cohorts.

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 Presented in Session 9. Marriage, Family, Households, & Unions; Gender, Race, & Ethnicity