Chris O'Leary looks afresh at the reasons for prosocial work choices in the first substantive critique of Public Service Motivation (PSM). With critical analysis of theoretical and empirical research to date, this book explores the pros and cons of PSM and interrogates the reasons why people choose to work in the public and third sectors. It proposes an alternative theory for the pursuit of service, rooted in rational choice theory, that shows public servants are expressly motivated to confirm their values and identity through their work. For those involved in public policy, administration and management, this is a constructive and stimulating review of an important but often neglected aspect of the sector.