How Factor Returns Change After Academic Publication

Summary

The document summarizes research on 97 factors reported in finance, accounting, and economics journals. It compares long-short portfolio returns across the original sample, a later out-of-sample period, and the period after publication to examine whether published factors retain their predictive power.

The summary reports that factor returns weaken significantly after publication, with larger declines for factors that had stronger returns in the original sample. Factors with higher arbitrage costs retain higher expected returns after publication. Trading activity, including turnover, dollar volume, and especially short selling, also increases after publication. Before publication, a factor’s returns correlate with those of unpublished factors; afterward, they become more closely related to published factors. These findings are presented as consistent with attention and behavioral comovement explanations. The document offers only an abstract-level account, without detailed methods, dates, or robustness tests, so it does not establish how results vary across individual factors or markets.

Key ideas

• The summary compares long-short returns for 97 factors across in-sample, out-of-sample, and post-publication periods.
• Factor return predictability declines significantly after academic publication.
• Factors with stronger original returns experience larger post-publication declines.
• Higher-arbitrage-cost factors retain higher expected returns after publication.
• Trading activity rises after publication, while factor return correlations shift toward published factors.

Tags

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.