Corporate Environmental Responsibility and Equity Prices

This paper uses an innovative way to screen stocks and analyzes the relationship between corporate environmental responsibility and long-run stock returns. By our definition, an environmentally responsible (green) company gives no environmental concern and shows environmental strength(s). Using 20 years’ data of 1992–2011, we find evidence that environmentally responsible company outperforms, in the 4th to 7th year after the screening year. An equal-weighted environmentally responsible portfolio earned an annual four-factor alpha of 4.06 % in the 4th year, 3.00 % above industry benchmarks, and 3.87 % above characteristic benchmarks. The results are robust to alternative portfolio weighting methodologies, controlling for firm characteristics, and the removal of outliers. Testing using industry-adjusted Tobin’s Q, we find consistent evidence that environmental strength creates firm value. We argue that environmental responsibility is an intangible asset, likely to be undervalued by the market, especially in the long horizon, thereby causing environmentally responsible companies to exhibit long-horizon excess returns.