It’s easy to make a pledge to do better: to exercise more, study harder, eat healthier food or make responsible financial decisions. But making these changes stick – for a week, a month and, ideally for a lifetime – is a thorny problem that has confounded both average folks and scientists alike. With the recently launched Behavior Change for Good Initiative , University of Pennsylvania psychology professor Angela Duckworth and Wharton professor of operations, information and decisions Katherine Milkman are hoping to come up with strategies for change that actually stick. Working with a team of scientists from different disciplines, they’re conducting some of the largest social science experiments ever in an effort to create easy, affordable tools that help people make better daily and long-term decisions about their health, education and savings. One of their first efforts is focused on helping people establish regular exercise habits.…