Economist Robert Frank studies peer pressure and how its power can be leveraged for good. In his new book, “Under the Influence: Putting Peer Pressure to Work,” Frank explains the idea of “behavioral contagion,” which he says can drive people to do what’s right. Paul Solman talks to Frank about applications for fighting climate change and real-life examples in Frank's hometown of Ithaca, New York. Stream your PBS favorites with the PBS app: to.pbs.org/2Jb8twG Find more from PBS NewsHour at www.pbs.org/newshour Subscribe to our YouTube channel: bit.ly/2HfsCD6 Follow us: Facebook: www.pbs.org/newshour Twitter: www.twitter.com/newshour Instagram: www.instagram.com/newshour Snapchat: @pbsnews Subscribe: PBS NewsHour podcasts: www.pbs.org/newshour/podcasts Newsletters: www.pbs.org/newshour/subscribe