“It may be that the recession has had a bit of a sobering effect on teenagers in the following respect: Maybe their parents are having a tough time. Maybe they have neighbors who have been unable to find a job. Maybe they have neighbors who have lost their home,” he said. Survey data on teens show “they are very, very pessimistic about their economic future. Maybe that has placed a governor of sorts on their sexual appetite.”

One factor Albert is disinclined to think is a reason for the decline in birth rate is an increase in abortions. “What we have seen in the past nearly two decades is that teen pregnancy, abortion, and birth rates were all declining at the same time. Put another way, the declines in teen births since 1991 have not been driven by increases in abortion but, instead, in decreases in the underlying pregnancy rate.”

Historically, teenagers from 18 to 19 years old are the most difficult to effect with messages of pregnancy prevention, but this year the 18-19 year olds followed in the downward trends. The decline in teenage birth rates also cut across all racial groups, and was particularly striking among Latinas, among whom 10 percent fewer had babies in 2009.