This book introduces a new topic; a critical researched-based analysis of the role of human judgment in social policy formation. It applies what has been learned from research on human judgment to specific examples - from the Challenger disaster to present-day debates on health care. Human judgment can be a source of both hope and fear in the creation of social policy. Yet this important process has rarely been examined because research on human judgment has been scarce. Now, however, the results of 50 years of empirical work offer an unprecedented opportunity to examine human judgment and the basis of our hopes and fears. Numerous examples from law, medicine, engineering, and economics are used throughout to demonstrate these and other features of human judgment in action.