Voluntary corporate climate initiatives and regulatory threat

Does participation in voluntary environmental initiatives affect firm value? We take a closer look at the Chicago Climate Exchange (CCX) and the Climate Leaders (CL), two US initiatives to curb carbon emissions that were operating during a decisive regulatory event. In 2009 the Waxman-Markey Bill surprisingly passed the House of Representatives and brought the US economy a big step closer to a nationwide CO 2 emission trading system. With an event study we assess how the stock market valued membership in the initiatives when the likelihood of CO 2 regulation unexpectedly increased. Our findings suggest that only membership in the market-based CCX was considered beneficial for a mandated carbon market. This is consistent with research that equity-based regulation through financial markets can help economies favor clean industries over dirty ones. We interpret the empirical results in a simple model. Adding earlier market reactions to the firms' membership announcements, the model implies that the market had been betting on a mandatory emission trading system all along.