This e-newsletter is the ninth in a series funded by the University of Michigan Demography Center. This issue, “Why Do We Make Bad Decisions? Findings From a New Science,” highlights National Institute on Aging-funded research that examines neuroeconomics–the integrated study of decision processes by economists, psychologists, and neuroscientists. Neuroeconomics is barely two decades old, and its practitioners hope to shed light on the aspects of decisionmaking that lead some people to prepare inadequately for their old age.