Americans are failing to save for retirement, investing their money foolishly, and choosing health insurance plans that poorly meet their needs. Why do so many of us make bad choices on such important issues? Recent scientific research shows that people are susceptible to cognitive biases. Because we are human, we are fallible, and because we are fallible, we can use some help. Richard H. Thaler and Cass R. Sunstein examine these issues in their new book, Nudge: Improving Decisions about Health, Wealth, and Happiness (Yale University Press, 2008). They argue that nudges can be deployed easily and inexpensively in many contexts, producing concrete benefits for real people.