Overconfidence and team-performance : an analysis of NBA-players' self-perception

We analyse the effect of overconfidence in a model of team-production with effort complementarities. We show that overconfidence may not only enhance an overconfident agent's effort but also that of a rational one. Focusing the agents' payoffs we see that this increase in effort can be to the agents' benefit, regardless whether they are rational or overconfident. We take this notion to NBA-data which we have gained from the season 2009/10 and see that players who have been identified as overconfident have a significantly positive effect on their team's success.