Arnold B. Bakker is full professor at the Department of Work and Organizational Psychology at Erasmus University Rotterdam, The Netherlands. His research interests include positive organizational behavior (e.g., flow and engagement at work, performance), burnout, crossover of work-related emotions, and serious games on organizational phenomena.Michael P. Leiter is Canada Research Chair in Organizational Health and Professor of Psychology at Acadia University and Director of the Center for Organizational Research & Development that applies high quality research methods to human resource issues. He is actively involved as a consultant on occupational issues in Canada, the USA, and Europe.