Date: May 2004There has been a general consensus that socially responsible investing (SRI) leads to inferior, rather than superior, performance. Using Innovest’s corporate ecoefficiency scores, the authors of this report provided evidence to the contrary. They composed two equity portfolios of different "eco-efficiency" ratings and found that over the period 1995-2003 the high-ranked portfolio gave substantially higher average returns than the low-ranked one. They showed that this difference could not be explained by differences in market sensitivity, investment style, or several other factors, and so concluded that the incremental benefits of SRI can be "substantial".