3) Millennials have alternatives. In the past, living together or having children “out of wedlock” was met with severe social stigma, but no longer. Cohabitation rates are on the rise — 48 percent of women interviewed between 2006 and 2010 for the National Survey of Family Growth cohabitated with a partner as a first union, compared with 34 percent in 1995.

Births to unmarried women also are on the rise. Forty-one percent of all births are now to unmarried women, 2.5 times as high as was reported in 1980 and 19 times as high as in 1940.

“Marriage is, in some ways, in the worst place it’s ever been,” said W. Bradford Wilcox, a sociologist at the University of Virginia, director of the National Marriage Project and founder of Demographic Intelligence. “I don’t think we’re ever going to see a major upswing. But we may have reached a plateau. The numbers suggest we may be touching bottom.”

Hopeful signs, Wilcox said, are rising rates of marriage among the educated.