Book excerpt: A desire to change behavior--getting people to eat better, approach child discipline differently, or even just take the bus--is at the root of a lot of social and social welfare programs. But the question of how we can bring about effective, lasting changes in behavior is a complicated one, drawing together a range of academic disciplines and fields of social research. This book explores the political and historical landscape of behavior change, covering political ideology, trends in academic theory, and new innovations in practice and research. In addition, it examines priorities that have become central to thinking in the field, such as ways of evaluating success and measuring return on investment.