Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Several recent studies document that sorting stocks first on certain stock-level characteristics and then on past returns results in elevated momentum profits. We show that such strategies enhance momentum profits simply by trading in stocks with more extreme past returns. Adjusted for this effect, elevated momentum profits resulting from characteristics (size, R-super-2, turnover, age, analyst coverage, analyst forecast dispersion, market-to-book, price, illiquidity, credit rating) disappear almost entirely. Interaction patterns have been used to support behavioral and limits-to-arbitrage explanations of momentum; our findings imply that explanations of momentum should instead focus on the link between momentum profits and extreme past returns. Copyright 2013, Oxford University Press.