Michele Belot and Jeroen van de Ven (2011)

Abstract This study presents evidence from a field experiment on the prevalence of favoritism at school. Children compete in teams in a tournament in a real effort experiment with two rounds. They report which group member they prefer to do the task in the second round, providing them with a small privilege. Using information about their social network and their individual performance, we are able to identify the importance of friendship ties. We find that friendships are very important for all age groups. Performance is an important criterion for the older children, but not for the younger ones. While this suggests that the children favor their friends, we also find an offsetting effect: children who are favored increase their subsequent performance. This means that, what looks like favoritism ex ante, may actually maximize performance ex post.