The last ten years have seen an enormous surge of interest in issues that are common to psychology and economics. How do people make decisions about economic issues? How should they make such decisions? Does public policy or regulation succeed in its aim of helping people make the decisions? What situations aid cooperation? This book explores some of the ways in which economists and psychologists have tried to answer these questions. The authors are an international mix of economists and psychologists who have tackled different aspects of these general questions. Overall, the book reflects the diversity and energy that characterise this growing inter-disciplinary field. This book was originally published as a special issue of New Zealand Economic Papers.