The Sibsize Revolution and Social Disparities in Children's Family Contexts in the United States, 1940-2012.

This article points to a sharp decline in children's sibling numbers (sibsize) that occurred in the United States since the 1970s and was large enough among children with lower socioeconomic status (SES) (particularly black children) to amount to a revolution in their family circumstances. It interprets sibsize decline as a source of social convergence in children's family contexts that ran counter to trends toward social divergence caused by the rise of lone parenthood. The article is based on new estimates of differences in children's sibsize and lone parenthood by race and maternal education generated from public-use samples from the Census of Population and Current Population Survey (CPS), focusing especially on the period 1940-2012. I discuss some methodological and substantive challenges for existing scholarship arising from the findings and point to questions for future research.