The MTV series "16 and Pregnant" follows a different young woman each week as she makes decisions about her life and the life of her child, and copes with her family's reaction. Devon Broyles allowed MTV's cameras to follow her for the program in season four. 

Each week as many as three million viewers tune in to "16 and Pregnant" and its spin-off, "Teen Mom." While some have criticized the show for making stars out of very young mothers, a new study co-authored by economist Melissa Kearney indicates that the show may actually help prevent teen pregnancy. 

Along with her her co-author Phillip Levine, Kearney, a professor of economics at the University of Maryland and director of the Hamilton Project, found that the show and its spin-off may have prevented more than 20,000 births to teenage mothers in 2010, reducing the teenage pregnancy rate by nearly six percent.

But how can these researchers be sure that this TV show prevented 20,000 births?

"It could have gone either way—we didn't know the way this particular media portrayal of teen pregnancy was going to resonate with teens," says Kearney.

This economist says that she and her co-author used sophisticated statistical analyses to get to the bottom of causal relationships and data.

"We worked very hard to relate viewership of this show to subsequent trends in teen childbearing," says Kearney. "The way we've done this is to look across markets in the USA and look in the places where more teens were watching this show. How did subsequent trends in teen childbearing relate to that viewership? What we find is that in places where more teens are watching MTV, we see larger decreases in rates of teen childbearing. This was pretty compelling evidence."

Kearney says that Google search and Twitter data were also examined as well. This data, Kearney says, helped the researchers to determine what teens were thinking while watching programs like "16 and Pregnant" and "Teen Mom."

"That confirmed for us what we were seeing in terms of the birth data," she says. "What we found in the Google and Twitter data was that when this show aired, the next day we saw large spikes in searches on Google for 'How to get birth control.'"

When examining the data from Twitter, Kearney says the researchers also saw large spikes of people tweeting about the television shows and birth control during the airing of these programs.

"In fact, those increases in searches and tweets correspond to the places where more young adults are watching MTV," she says. 

But what is the impact of "16 and Pregnant" on the national teen birthrate? Kearney says that the data suggests that this show has led to a 5.7 percent reduction in teen births in the 18 months since it first aired in 2009.

"That is a very large effect," says Kearney. "I also want to emphasize that it is a plausible effect. We know over this period since the show aired starting in 2009, there was a steep rate of decline off of an ongoing trend. We attribute half of that steepness to the Great Recession—births respond to economic conditions, and that's true of non-teen births and teen births. When it's harder to get a job to support your family, fewer people have babies. This show accounts for a third of the decline."

Broyles, who is 19-years-old and has joint custody of her 2-year-old son, says she did not become pregnant to land a spot on television.

"I wanted people to see the reality of it—to get the message out there that it's not easy," says Broyles. "I see young girls and they're talking about getting pregnant. It's not how people portray it and that's what the show kind of shows."

Broyles says she doesn't recommend that other young women follow her lead.

"If I could prevent one pregnancy that would be amazing," she says. "It is not easy being a teen parent."