Writing for Vox, Sarah Kliff had a good article last week about the recent decline in the teen pregnancy rate. Between 2007 and 2013 the number of babies born to teens declined by 38.4 percent. The teen abortion rate has declined as well, so the teen birth decline is not due to more teenagers obtaining abortions; it is due to fewer teenagers getting pregnant in the first place.

The teen birth rate has been declining since the early 1990s, but the decline has become sharper in recent years. This public-policy development has received some mainstream-media coverage. However, most media outlets reflexively give greater contraception use nearly all of the credit — while excluding other possibilities. To her credit, Kliff does some research and finds this explanation lacking.

Kliff does find evidence that teenagers have become more likely to use IUDs since 2002. However, she correctly points out that as of 2009 less than 5 percent of teenagers were using long-acting reversible contraceptives (LARCs). As such, this, by itself, cannot account for the substantial decline in teen pregnancy rates. Furthermore, Kliff discovers that the percentage of teens not using any contraceptive method has slightly increased between 2009 and 2013. Kliff, unlike many in the media, also publicly acknowledges that teen sexual activity has been declining since the early 1990s.

In the article, Kliff does a nice job explaining why experts are puzzled as to why teen pregnancy rates are declining. Sex education still varies greatly from region to region. Some localities have made substantial investments in trying to reduce teen pregnancy, while others have not. The slow economy might be playing a role, but other economic slowdowns did not have a similar effect. Additionally, trends in contraception use clearly do not tell the whole story

The most interesting explanation has been offered by economists Philip Levine of Wellesley College and Melissa Kearney of the University of Maryland. They argue that MTV television shows Teen Mom and 16 and Pregnant are have an impact on the behavior of teenagers. Their statistical analysis finds that, holding other factors constant, regions with high rates of Teen Mom viewership have seen larger teen birth-rate declines than have other parts of the country. According to Vox, their research has yet to be published in a peer-reviewed journal. However, it is still an interesting explanation.

All in all, the consistent decline in the teen pregnancy rate is a welcome phenomenon. Kudos to Kliff for giving reductions in teen sexual activity some credit and acknowledging that contraception use is not the whole story.

— Michael J. New is an assistant professor of political science at the University of Michigan–Dearborn and an associate scholar at the Charlotte Lozier Institute in Washington, D.C.