Family Norms and Declining First-Marriage Rates: The Role of Sibship Position in the Japanese Marriage Market

This study explores how changes in sibship com po si tion asso ci ated with fer til ity decline may, in con junc tion with entrenched fam ily norms and expec ta tions associated with specific sibship positions, impact marriage rates and further reduce fer- til ity. We eval u ate this pos si bil ity by focus ing on Japan, a soci ety char ac ter ized by half a century of below -replacement fertility and widely shared family norms that associate eldest (male) children with specific family obligations. Harmonic mean models allow us to quan tify the con tri bu tion of changes in both mar riage mar ket com po si tion with respect to sibship position and sibship-specific pairing propensities to the observed decline in marriage rates between 1980 and 2010. One important finding is that mar- riage pro pen si ties are lower for those pairings involv ing men and women whose sibship position signals a higher potential of care giving obligations, especially only -children. Another is that changes in marriage propensities, rather than changing sibship com- po si tion, explain most of the observed decline in mar riage rates. We also found that mar riage pro pen sity changes mit i gate the impact of the chang ing sibship com po si tion to some extent. However, the limited contribution of changing sibship composition to the decline in first -marriage rates provides little support for a self -reinforcing fertil- ity decline via the rela tion ship between chang ing sibship com po si tion and mar riage behavior.