Are Complex Families Becoming More Common?

Maria Cancian, University of Wisconsin-Madison
Daniel Meyer, University of Wisconsin-Madison
Steven Cook, University of Wisconsin-Madison

In earlier work (Demography, 2011) we documented high levels of family complexity for a cohort of first born nonmarital children in Wisconsin: 60 percent had half siblings by age 10. This paper extends that work, comparing complexity among children born in 1997, 2002 and 2007. We find high levels of complexity: by age 15 members of the 1997 cohort are more likely to have at least three half-siblings than to have none. However, the risk of complexity declines across cohorts: at age 5, the proportion with half-siblings falls from 50 to 48 to 44 percent for the three cohorts. This is partly explained by the composition and timing of nonmarital births (older parents who are less likely to be Black). Nonetheless, because the pool of those at risk (nonmarital births) is growing, some measures of the number of children in complex families increase.