Are polluters shunned? A study on the institutional ownership and returns of polluter stocks

We hypothesise that societal norms cause institutional investors to discriminate against polluters. Consistent with this hypothesis, we document relatively lower institutional ownership for the most polluting firms in the United States. Institutional discrimination against polluters increases over 1987–2018, in line with increasing environmental awareness. Institutions are primarily averse to investments in dioxin emitters. Institutions that prioritize portfolio performance are less sensitive to societal norms against polluters, as are institutions with shorter investment horizons and more aggressive trading strategies. Lastly, we test whether investor discrimination affects polluter equity valuations and creates systematic trading opportunities, but find no convincing evidence of a polluter return premium.