(CBS) The average age of marriage is increasing to 26.5 years old for women and 28.7 years old for men. That's up from ages 23 and 26 in 1990, respectively. But, the median age of first birth for a woman is now 25.7 -- meaning that about 48 percent of first births happening outside of wedlock.
The information was presented in a report titled "Knot Yet: The Benefits and Costs of Delayed Marriage in America." It was sponsored by the National Marriage Project at the University of Virginia, the National Campaign to Prevent Teen and Unplanned Pregnancy and the RELATE Institute. Information was compiled from a number of studies and government surveys.
Researchers believe that many couples are waiting to get married because of economic and cultural reasons. Many jobs for Americans that may not have higher education no longer exist. A middle-class lifestyle now requires more schooling, meaning young adults are spending more time pursuing education. In addition, many young adults now view marriage as a "capstone" instead of a "cornerstone" in their lives, meaning that they are waiting until they have everything else in place -- including a job -- before tying the knot.
"The ones who are not marrying are the ones who don't have the job prospects, don't have the economic stability," Stephanie Coontz, a co-chair of the non-profit Council on Contemporary Families who was not involved in the report, told USA Today.
But, twenty-somethings aren't waiting to have children, according to the report. Forty-four percent of American women will have given birth by the time they are 25, but only 38 percent are married by that age. By 30, two-thirds of women will have had a child out of wedlock.
The average age of first birth for women who drop out of high school is 20, while their average married age is 25. Eighty-three percent of first births to non-high school graduates are to unwed mothers.
The biggest rise in unmarried pregnancy is among the 54 percent of "middle American" women, which include women who have graduated high school and completed some college but do not have a degree. In this group, the average age of having their first child is 24, and they are married at 27. Fifty-eight percent of the first births in this group are to unwed mothers.
"The Great Crossover marks the moment at which unmarried motherhood moved from the domain of our poorest populations to become the norm for America's large and already flailing middle class," report co-author Kay Hymowitz, William E. Simon Fellow at the Manhattan Institute, said in a press release.
Young unmarried parents are statistically more likely to be poor, have emotional or behavioral problems and are less likely to do well in school, according to information released by the New York City Office of the Mayor in conjunction with a teen pregnancy PSA campaign. Young men are also less likely to be involved with their children.
The researchers determined there was a 13 percent chance that married couples with a child will split within the first five years of the child's life. If the couple was unmarried but living together, the chance they will break up increases to 39 percent.
"The biggest downside to delayed marriage in America is that many young adults are now putting the baby carriage before marriage," co-author and National Marriage Project director Bradford Wilcox, an associate professor of sociology in University of Virginia's College of Arts & Sciences, said in a press release. "What they often don't realize is that children born outside of marriage are significantly more likely to be exposed to a revolving cast of caretakers and the social, emotional and financial fallout associated with family instability and single parenthood."
Delaying marriage was also shown to stunt the emotional and social growth of young adults -- including men in their twenties. According to the National Longitudinal Study of Adolescent Health, young adults who were unmarried were more likely to report lower levels of satisfaction with their lives, drink more alcohol and be depressed compared to their married peers, the researchers pointed out.
The researchers also found that 35 percent of single twenty-something men and co-habiting men are "highly satisfied" with their lives, compared to 52 percent married men. For women, 33 and 29 percent of single and cohabiting women are "highly satisfied" respectively. Forty-seven percent of married women claim the same status.
One upside to delayed marriage is that it has been linked to a decline in the U.S.'s divorce rate since the 1980s. Couples that marry in their teens and early 20s are more likely to divorce than people who marry later.
Waiting until you have jobs may be a good thing. Susan Brown, co-director of the National Center for Family and Marriage Research at Bowling Green State University, told USA Today that marriage for less-educated couples may not be the best move. One of the biggest factors in divorce is financial instability.
"We do know that people with lower levels of education who get married are more likely to get divorced," she pointed out. Brown conducted some of the research, but did not write the study.
For women who have more education -- about 37 percent of the population -- it may be best to wait to get married. A college-educated woman who waits until 30 or later to get married can expect an average annual salary of $50,415. However, if she gets married before the age of 20, that salary expectation drops to $32,263. (A woman who never gets married can expect to make a few thousand dollars more than her counterparts who tie the knot in their 30s.)
In addition, this group of college-educated women are still having their first child two years after they get married on average.
On the opposite side, men's salary tends to peak a little over $80,000 a year if they get married in their late 20s. Any longer, their salary declines rapidly.
"Marriage delayed is the centerpiece of two scripts that are helping create two different outcomes and two different life chances for the next generation," Hymowitz said in a press release. "For the college-educated third of our population, it has been a success. For the rest, including large swaths of Middle America, not so much."
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