Biased surveys

We find empirical evidence that surveys of professional forecasters are biased by strategic incentives. First, we find that individual forecasts overreact to idiosyncratic information but underreact to common information. We show this is consistent with a model of strategic diversification incentives in forecast reporting where forecasters want to optimally “stand out” from the crowd, and thus report forecasts that exaggerate the agents’ true beliefs. Second, we show that no such biases are present in forecasts data that is not subject to strategic incentives. We also test further comparative statics that also confirm the strategic incentive model. Overall, we conclude that strategic reporting biases the inference an econometrician can draw on the true underlying expectations formation process, and the precision and heterogeneity in agents’ information sets, and lastly we show how to correct for this.