This discussion paper resulted in a publication in the German Economic Review , 16(3), 343-366. We examine differences in altruism and laziness between public sector employees and private sector employees. Our theoretical model predicts that the likelihood of public sector employment increases with a worker's altruism, and increases or decreases with a worker's laziness depending on his altruism. Using data from the German Socio-Economic Panel Study, we find that public sector employees are significantly more altruistic and lazy than observationally equivalent private sector employees. A series of robustness checks show that these patterns are stronger among higher educated workers; that the sorting of altruistic people to the public sector takes place only within the caring industries; and that the difference in altruism is already present at the start of people's career, while the difference in laziness is only present for employees with sufficiently long work experience.