Think of it as a new "normal'' in American family life. After creeping slowly and steadily upward most of the last 50 years, the number of babies born to young unmarried women quietly crossed a threshold in 2006.
For the first time in a half-century of record-keeping, a majority of babies born to women younger than 30 were delivered by single women.
That year, women such as Sara Bell of Lexington, Mo., delivered 50.4
SINGLE MOTHER BIRTHS• In 1960, 6 percent of babies born to women under 30 were born to unmarried women. By 2006, that figure had grown to 50.4 percent.• Babies born to single mothers are closely correlated with education. In 2005-2006, 67 percent of babies born to high-school dropouts under 30 were born to unwed women. Among high-school graduates with no further education, the figure was 52 percent. Among college graduates, it was 14 percent.
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percent of the children born to those under 30, said Andrew Sum, an economist at Northeastern University in Boston.
The nation got a reminder that unwed pregnancies can happen anywhere when Republican vice presidential candidate Sarah Palin announced that her 17-year-old daughter, Bristol, was five months pregnant. The family said Bristol will keep the baby and marry the baby's father.
Bell, now 24 and newly married, bore her first child when she was 19 and single. That baby died a day later, and Bell went on to give birth to two more children, with different fathers.
As a college student, she was burdened with homework as well as the draining work of caring for two children. She remembers the thought that danced through her mind during moments of exhaustion.
"There were times when I was like, ‘This is why people marry when they have a kid.' ''
Bell had a great deal of help from her mother and relatives. In June, she tied the knot, shifting her single-mother status to married with children, solidly middle class with two paychecks.
For the vast majority of single young mothers, however, that's not the story. In fact, Sum, who directs Northeastern's Center for Labor Market Studies, warns that the burgeoning number of such families presages "disaster."
His 2006 calculations are his most recent.
"The inequality of incomes in these families is unbelievable," said Sum, who has written numerous books and articles about the job market, young families and poverty.
‘‘Forty percent are poor, or near-poor. A large fraction is dependent on public assistance. Unless the mother is very well-educated and has a bachelor's degree or above, there's a huge fiscal cost to the rest of us."
Most of the mothers are not college-educated. In fact, the story of the American family has split into two widely divergent realities, according to Sara McLanahan, a professor of sociology and public affairs at Princeton University.
By and large, she said, college-educated women are marrying later, having babies within a marriage and divorcing less. Their husbands are spending more time with the children.
Women without a college degree are doing just the opposite -- and in growing numbers.
"The next generation of children is going to be much more unequal than what we have today," Sum said. "You're going to have a really elite group and a group that will massively fall behind. These gaps are really extraordinary. I testified before Congress and said, ‘Look, guys, we really need to face this.' ''
Sum advocates providing more public assistance and tax breaks for low-income families, especially those in which the parents are married and working.
Private family miseries translate into major public burdens, he said.
"You can't raise revenue from families that have such a low income," Sum said. ‘‘And you have to spend so much more to keep them afloat."
He estimates that taxpayers pony up about $7,000 a year to support the typical family of an unwed mother without a high-school diploma.
"Our ability to afford this has come to an end."
Others have weighed in on the issue lately, as well. The Institute for American Values published a study in April that pegged the annual cost to taxpayers of children living with a single parent -- whether because of divorce or an out-of-wedlock birth -- at more than $112 billion annually.
Fatherless families also earned a mention from Democratic presidential nominee Barack Obama. He chose Father's Day to chastise men in the black community in particular for failing to perform any duties of fathering beyond the act of conception.
Sen. Sam Brownback, a Kansas Republican, was one of the authors of an opinion piece in The Wall Street Journal in May. It made the case that although the government largely has abolished the "marriage penalty'' in the tax structure, it still in effect penalizes marriage among low-income people by cutting government benefits should they marry.
Princeton's McLanahan has been trying to gain a better understanding of this burgeoning family form with a 10-year effort known as the Fragile Families and Child Well-Being Study. McLanahan and her research team initially interviewed 5,000 couples, three-fourths unwed, upon the births of their children, starting in 1998.
The researchers have interviewed them periodically since then.
Their lives are complicated in many ways, she said.
At the time of an out-of-wedlock birth, she said, about half of the couples live together. But because two-thirds of those relationships typically dissolve by the time a child turns 5, "There's a lot of instability. A lot of these women form relationships with new men, and have children with the new men. There are people moving in and out. Those are dramatic events in a woman's and a child's life.
"The other piece is . . . managing a household of so many different contributors of time and money. So you have a woman with three children by three fathers. Imagine the complexity, just arranging visits and trying to arrange for child-support payments -- if they come."