The exact motivations for a 'green' and/or stakeholder approach to business are often unclear, though many view these approaches as beneficial to business over the long-term. This study specifically examines the incentives that stock market investors provide for companies to adopt an environmental program or environmentally friendly practices within their business. It also addresses the possible motivations that those companies might give investors in return. Voluntary company participants of the Environmental Protection Agency's 33/50 Program are used in econometric regressions that analyze both stock price and earnings per share changes before and after the program was began, from 1987 to 2007. After controlling for firm-specific and market variables, the stock price data concludes that investors do value the 33/50 program over the long-run. To address the efficient markets hypothesis, a time period analysis is performed. It does not find significant over- or underreaction evidence, but instead shows greater overall price increases over time with lower predictability. Whether or not the investors should have valued the 33/50 program, as would be indicated by long-run earnings growth, is largely inconclusive.
