Pianists who achieve high scores in the Queen Elizabeth musical competition are rewarded by subsequent success. This is not surprising in itself, but it is not immediately clear whether this is caused by the score or because those who have high scores are better pianists. Data on eleven consecutive competitions make it possible to distinguish between the two explanations, since an unexpected situation allows us to use an instrumental variable (the randomly assigned order in which musicians appear at the competition), uncorrelated with ability, but correlated with the results of the competition.

DSA Proof. - Universe: The data was collected from competitors in eleven piano competitions held between 1952 and 1991.