By SABRINA TAVERNISE
WASHINGTON - The number of Americans who have children and live together without marrying has increased twelvefold since 1970, according to a report released Tuesday. The report states that children now are more likely to have unmarried parents than divorced ones.
The report was published by the National Marriage Project, an initiative at the University of Virginia, and the Institute for American Values, two partisan groups that advocate for strengthening the institution of marriage. The report argues that the rise of cohabitation is a growing risk for children, and that their lives are less stable in such families.
The report cites data from the Census Bureau as well as the Centers for Disease Control and Prevention, and includes work from 18 researchers who study family issues.
According to the National Survey of Family Growth, part of the Centers for Disease Control, 42 percent of children have lived with cohabiting parents by age 12, far more than the 24 percent whose parents have divorced.
The numbers also suggest a correlation with class. Americans with only a high school diploma are far more likely to cohabit than are college graduates, according to the report.
"There's a two-family model emerging in American life," said W. Bradford Wilcox, director of the National Marriage Project and an associate professor of sociology at the University of Virginia. "The educated and affluent enjoy relatively strong, stable families. Everyone else is more likely to be consigned to unstable, unworkable ones."
Cohabiting parents, Mr. Wilcox said, are more than twice as likely to break up as parents who are married.
The increase in unmarried couples cohabitating and having children swept poor communities beginning in the late 1960s, Mr. Wilcox said, citing data from the National Survey of Family Growth, and now has moved into working class and lower-middle-class families.
Out-of-wedlock births among white women with a high school diploma rose more than sixfold in recent decades, the report said, jumping to 34 percent in the late 2000s, from 5 percent in 1982. In contrast, the rate for white college graduates stayed flat at about 2 percent.
While births to white women in cohabiting relationships rose by about two-thirds from the early 1990s to the mid-2000s, the proportion jumped by about half for black women and nearly doubled for Hispanic women, though that increase was affected by a large influx of immigrants, said Sheela Kennedy, a research associate at the Minnesota Population Center, which conducts demographic studies and whose work was cited in the new report.
"There's growing evidence that families that would be unstable anyway are just skipping marriage," Ms. Kennedy said.
The report cited studies in the Journal of Marriage and Family, and in Sociology of Education, asserting that children in cohabiting families tend to perform worse in school and be less psychologically healthy than those whose parents are married.
It also cited a 2010 report on child abuse by the federal Department of Health and Human Services that found that children living with two married biological parents had the lowest rates of harm - 6.8 per 1,000 children - while children living with one parent who had an unmarried partner in the house had the highest incidence, at 57.2 per 1,000 children.