Does the stock market fully value intangibles? Employee satisfaction and equity prices
February 12, 2008
The primary finding of the study by Alex Edmans (University of Pennsylvania) is that an equal-weighted portfolio of these companies outperforms the broader market, even after adjusting for differences in size, valuation, and momentum. Using a Carhart (four factor) model, the author finds unexplained monthly returns (alpha) of +0.52% (significant at the 1% level) for an equal-weighted portfolio of these stocks (rebalanced each February following the publication of the new list). The finding appears quite robust — portfolios constructed using slightly different construction rules (e.g., no rebalancing) had monthly alphas ranging from +0.22% to +0.43%.
The study also compares the stocks to appropriate industry benchmarks, and to companies with matched characteristics. In each case the best companies to work for had statistically significant positive alpha, ranging from +0.25% to +0.46% per year — all alphas were statistically significant at either the 1% or 5% level.
The author concludes that “employee satisfaction is positively related to corporate performance...the findings imply that the market fails to incorporate intangible assets fully into stock valuations — even if the existence of such assets is verified by a widely respected survey.”
This study was awarded the 2007 Moskowitz Prize (awarded by the Center for Responsible Business at the
Haas School of Business, in cooperation with the Social Investment Forum, the Moskowitz Prize promotes the concept, practice, and growth of socially responsible investing).
This article was previously published on stristudies.org, February 12, 2008.
Summary by Alex Edmans