Rich Lowry, National Review Online, 8/26/2011
... But it only means that marriage is unraveling in a different way. According to a new study by the Institute for American Values and the National Marriage Project at the University of Virginia, cohabitation has increased 14-fold since 1970. About 24 percent of children are born to cohabiting couples, more than are born to single mothers, while another 20 percent experience a cohabiting household at some time in their childhood. On the face of it, this doesn't seem alarming. At least there are two adults there for the kids. Except the research says it isn't enough. Children in cohabiting households tend to lag children in intact married families on key social indicators and are not much better off than children in single-parent families.