"Do We Follow Others when We Should? A Simple Test of Rational Expectations": Comment

Weizsäcker (2010) estimates the payoff of actions to test rational expectations and to measure the success of social learning in information cascade experiments. He concludes that participants perform poorly when learning from others and that rational expectations are violated. We show that his estimated payoffs rely on estimates of the publicly known prior and signal qualities which may lead the formulated test of rational expectations to generate false positives. We rely on the true values of the prior and signal qualities to estimate the payoff of actions. We confirm that the rational expectations hypothesis is rejected, but we measure a much larger success of social learning.