Interval Elicitation of Forecasts in a Prediction Market Reveals Lack of Anchoring "Bias"

Abstract

In an online prediction market, forecasters who could not see the current state of the market until they made their own separate estimates moved their estimates closer to the market forecast when the current state of the market became known. Their first edits to the market forecast were very similar to the first edits of forecasters who could always see the current state of the market, and forecasters in both conditions had similar accuracy. These results suggest that our more elaborate forecast elicitation method might not improve forecasts and that any anchoring on the state of the market does not constitute an error in judgment.