We relate US portfolio returns, book-to-market values and excess stock returns to different dimensions of socially responsible performance. We find that socially responsible investing (SRI) impacts on stock returns by lowering the book-to-market ratio and not by generating positive alphas. Our result is consistent with the theoretical work suggesting that SRI is reflected in demand differences between SRI and non-SRI stock. It also explains why so few studies are able to establish a link between alpha’s and SRI.