As the amount of information available to individuals about their health status grows, important questions arise about whether people really want that information and what they will do when they get it. At this Harper Lecture, Emily Oster discussed the demand for and use of health information. Using data on individuals at risk for Huntington's disease, Oster described patterns in the demand for information and in how economic choices change when people get that information. Emily Oster is an associate professor of economics at Chicago Booth and currently serves as a faculty research fellow for the National Bureau of Economic Research. She is the author of Expecting Better: Why the Conventional Pregnancy Wisdom is Wrong—and What You Really Need to Know.