Since 1950, marriage behavior in the United States has changed dramatically. Though most men and women still marry at some point in their lives, they now do so later and are more likely to divorce. Cohabitation has become commonplace as either a precursor or an alternative to marriage, and a growing fraction of births take place outside marriage.…

Robert Hummer and Erin Hamilton note that the prevalence of fragile families varies substantially by race and ethnicity. African Americans and Hispanics have the highest prevalence; Asian Americans, the lowest; and whites fall somewhere in the middle. The share of unmarried births is lower among most foreign-born mothers than among their U.S.-born…