Ms. Kearney and Mr. Levine examined birth records and Nielsen television ratings, finding that the rate of teenage pregnancy declined faster in areas where teenagers were watching more MTV programming — not only the “16 and Pregnant” series — than in areas where they did not. The study focuses on the period after “16 and Pregnant” was introduced in 2009 and accounts for the fact that teenagers who tuned in to the show might have been at higher risk of having a child to begin with.