Working papers

Extrapolators and Contrarians: Forecast Bias and Individual Investor Stock Trading,

with Steffen Andersen, Stephen Dimmock, and Kasper Meisner Nielsen. Download paper. Online Appendix.

Presented at Aarhus University, Academy of Behavioral Finance and Economics, Australia National University Summer Camp, Bank of England Workshop, Copenhagen Business School, CEPR Household Finance Conference, ESSEC Business School, FIRS Conference, Frankfurt School of Management, Goethe University, Helsinki Finance Summit, IESEG Business School, London Business School, Tilburg University, Toulouse School of Economics, University of Alabama, University of Geneva, University of Hawaii, University of Zurich, and the Workshop on Micro Data Meet Macro Models

Abstract: We test whether forecast bias affects individual investors’ stock trading by combining bias measures from laboratory experiments with administrative trade-level data. On average, subjects exhibit positive forecast bias (extrapolators), while a large minority exhibit negative bias (contrarians). Forecast bias is positively associated with past excess returns of purchased stocks: Extrapolators (contrarians) purchase past winners (losers). Forecast bias is negatively associated with capital gains of sold stocks. Forecast bias explains investor heterogeneity in the relation between market returns and net flows to stocks. Our study shows that forecast bias links past returns to trading decisions for purchases, sales, and net flows.