An April 2014 Urban Institute study predicts that if current marriage rates do not rebound, just 69 percent of Millennial women (and 65 percent of men) will marry by the age of 40. By contrast, in 1990, 91 percent of U.S.-born women had married by the age of 40. Almost none of this retreat from marriage will be felt among college-educated white Americans. The majority of college-educated Millennials will marry and have their children in marriages that last until the death of one partner. Meanwhile, the average American lives in a world where sex is plentiful but stable families are...