There is good news — and some familiar bad news — in recent research into the stubborn question of why our babies have babies when it is such a spectacularly bad idea for both mother and child.
The Centers for Disease Control and Prevention said last week that teen births have hit an all-time low. In 2010, there were 34.4 births per 1,000 women ages 15 to 19, a 9 percent drop from the year before.
What makes this news even more welcome is that the birthrate among teens ticked up in the mid-2000s after 20 years of declines, and researchers were at a loss to explain why.
Researchers are cautiously attributing the decrease to the public service campaigns that urge kids to delay sex for a while, and then to use contraceptives the first time and every time. Sarah Brown, CEO of the National Campaign to Prevent Teen and Unplanned Pregnancy, even thinks the "Teen Mom" reality shows may have played a role, too.
But the bad news is, American teens continue to be at least twice as likely to get pregnant as teens from 20 other industrialized countries, and nine times more likely than teens in Switzerland. More bad news: Teen birthrates are above 50 percent among African-Americans and Hispanics in the United States.
Social scientists have long believed that teen pregnancy is a function of poverty and hopelessness. Why not have a baby to cuddle and love, and who will love you back, if that is the norm in your community and if it will garner you some positive attention, at least for a while? This is even easier if you don't see a way out for yourself or for anyone you know.
But this link between poverty and early, unmarried childbearing has been a kind of soft link, born of anecdote and observation as much as anything.
Now a pair of economists are reporting a concrete connection between poverty and teen pregnancy, and they conclude that breaking that link will require major public policy efforts and not just more lectures about using birth control.
In their research, Melissa Schettini Kearney of the University of Maryland and Phillip B. Levine of Wellesley College controlled for just about everything: welfare benefits, abortion restrictions, health insurance, federal abstinence programs, unemployment, religion, race, political persuasion, rates of incarceration, "anything that you would think would affect decision-making," said Ms. Kearney.
All that was left at the bottom of the coffee cup was income inequality.
The researchers had found something that allowed them to move from correlation to causation. Poverty and hopelessness are the main reasons teens might decide to have a child out of wedlock; they are the main reasons they drop out of school and the economic mainstream.
Teen pregnancy is a symptom of poverty, not a cause, the researchers found. They are not poor because they had babies as teens. They are just still poor. As a matter of fact, teens in poverty who do not have children do not have significantly better outcomes as a result, the researchers found.
"They choose nonmarital motherhood at a young age instead of investing in their own economic progress because they feel they have little chance of advancement," the researchers report.
The CDC report found that Mississippi had the highest teen pregnancy rate, and New Hampshire had the lowest. You might conclude that is because there are more poor people in Mississippi than there are in New Hampshire. But the reason for the difference is not as simple as that.
It is not the number of poor, nor the vast space between the very rich and the very poor, that makes the difference. It is the distance between the very poor and those in the middle that is the source of the hopelessness.
If the gap between you and those just above you seems vast and unbridgeable, if no one you know has made it, why not drop out of school, drop out of the economy? Why not have a baby to love?
Susan Reimer's column appears Mondays. Her email is email@example.com.