Among 25-to-34 year olds, 45 percent are married. (By comparison, in 2000, 55 percent of Americans in that age group were married; in the 1960s, more than 80 percent were.)
In an interview with NPR's Melissa Block, Andrew J. Cherlin, author of The Marriage-Go-Round: The State of Marriage and the Family Today, said that, "for college-educated young adults, this is a story of postponing marriage."
The want to finish graduate school, maybe have a couple of years as a law firm associate, and then get married. So, they're waiting longer and longer until they have the rest of their lives in order before they get married.
For people without a college degree, some of them are postponing too, but some of them will never make it to the altar. We really will see probably a decline in the lifetime percentages of ever marrying for them.
According to Cherlin, increasingly, many Americans get married when it makes sense financially.
Cherlin said "marriage is an economic decision now."
They don't think they have what it takes economically to get married, but they're not willing to wait to have a kid, and so they have one.
That has become even truer recently, during the economic recession, he said.
There is something hidden in the statistics, Cherlin noted. More and more unmarried couples are living together, so they count as single people.
That may illuminate another interesting piece of data: 41 percent of births in the U.S. in 2008 were out of wedlock. According to Cherlin, many of those children probably were born to cohabitating, but unwed couples.