“Cohabitation, once rare, is now the norm: The researchers found that more than half (54 percent) of all first marriages between 1990 and 1994 began with unmarried cohabitation. They estimate that a majority of young men and women of marriageable age today will spend some time in a cohabiting relationship.
“…Cohabiting relationships are less stable than marriages and that instability is increasing” -The National Institute of Child Health and Human Development
In the United States and in the UK, couples who live together are at a greater risk for divorce than non-cohabiting couples.
Cohabiting couples had a separation rate five times that of married couples and a reconciliation rate that was one-third that of married couples.
As marriage rates have fallen, the number of U.S. adults in cohabiting relationships has continued to climb, reaching about 18 million in 2016. This is up 29% since 2007, when 14 million adults were cohabiting, according to U.S. Census Bureau data.