AUDIE CORNISH, HOST:
The U.S. has long had one of the highest teen birth rates in the developed world. But in recent years, it's been dropping, fast. There are several reasons why. And in a new study, researcher Melissa Kearney explains why she believes one big reason, it's MTV. Specifically, a show popular with teen girls called "16 and Pregnant," a brutally honest look at life as a pregnant teen.
(SOUNDBITE OF TV SHOW, "16 AND PREGNANT")
UNIDENTIFIED MAN: I was happy before.
UNIDENTIFIED WOMAN: OK. When?
UNIDENTIFIED MAN: I don't remember how long ago. It was a while ago.
UNIDENTIFIED WOMAN: Well, it didn't until you just knew I got pregnant. I mean, I don't think if we were in this situation, we would be this unhappy right now.
UNIDENTIFIED MAN: No. If we didn't have a kid, we wouldn't be together.
CORNISH: Melissa Kearney is associate professor of economics at the University of Maryland. And let's start with the basics. The teen birth rate has been dropping for more than two decades, right? So let's put that out there. But you noticed in around 2008, it started dropping even faster.
MELISSA KEARNEY: That's right. A lot of people noticed that the decline accelerated and, as you said, it started dropping very rapidly. And my colleague and I would read in the newspaper various theories as to why, and everybody promoting their favorite policy being it expanded sex education or expanded abstinence programs. And based on our previous research, we knew that those types of targeted policies could not be the explanation.
And then we came across a quote by Sarah Brown at the National Campaign to Prevent Teen and Unplanned Pregnancy, and she speculated that this show was having an effect. And so we wondered if that could be true and we set out to look at the data and see, in fact, if it was.
CORNISH: So let's talk about that data. What can you kind of possibly - what are the data sets that have to be matched together to figure out how you study the effect of one TV program on something like the birth rate. Where do you start?
KEARNEY: So we started by, of course, using the birth rate data in the U.S. So we're able to figure out exactly how many teens gave birth in various media markets. And then we bought data from Nielsen - ratings data - to figure out how many teenagers were watching MTV across the country. And then also in something a bit novel for economists, we got all historical data on Google searches, as well as the universe of Twitter data.
CORNISH: So talk to us about those Google searches or those tweets. What exactly did you see? What kind of terms did you look for?
KEARNEY: OK. In the Google data, we were really looking for what - were people searching for information about how to get birth control around the time the shows were viewed. And the day that an episode airs and the next day, we see large spikes in the rate at which people are searching for how to get birth control. And we see higher volumes of searches in places where more teens are watching MTV.
The Twitter data was astounding. In the Twitter data, we can actually see what teens are tweeting. And there are literally thousands of tweets that say things like: watching "16 and Pregnant" reminds me to take my birth control; "16 and Pregnant" is the best form of birth control. So getting that insight into what teenagers were thinking about while and right after they watched the show was really informative.
CORNISH: So once you've crunched all these numbers, what did you find? What kind of influence did the show have?
KEARNEY: The show had a sizeable impact. So our estimates from the data suggest that teen birth rates, as a result of this show, fell by 5.7 percentage points over this 18-month period. That is a third of the overall decline in teen birth rates over that time. So the full scope of what we find is that this decline in this period, half is due to the recession, a third is due to "16 and Pregnant," and the remainder is due to an ongoing downward trend in teen childbearing rates.
CORNISH: Now, stepping back for a moment, you know, your research really cuts to the heart of a perennial media question about, you know, are teens influenced by what they see on TV, whether it's seeing other teens struggling as teen mothers or watching something violent. Does your study suggest essentially that what they watch makes a difference?
KEARNEY: Yeah. Absolutely. That, we think, is the biggest takeaway from this study is that what teenagers are watching can make a really big difference in what they think and, ultimately, how they behave and really important life decisions.
CORNISH: Melissa Kearney, she is associate professor of economics at the University of Maryland. Thank you so much for talking with us.
KEARNEY: Thank you for having me.