Successful corporate social responsibility efforts by investors with U.S. companies lead to an excess annual return of 4.4 percent, concludes a study that won a global prize for socially responsible investing.

The winning paper that won the 2012  Moskowitz Prize was announced last night at The SRI Conference at the Mohegan Sun Conference Center in Connecticut. The authors of the paper, "Active Ownership," are Oguzhan Karakas, assistant professor at the Carroll School of Management at Boston College; Elroy Dimson, emeritus professor of finance at the London Business School; and Xi Li, assistant professor at the Fox School of Business at Temple University.

Karakas said at a session today that the three researchers studied a well-known SRI asset management firm (he would not identify the firm by name) and looked at 2,152 corporate social responsibility (CSR) efforts, or engagements, the asset manager had undertaken between 1999 and 2009 with 613 public companies. The researchers found that approximately 18 percent of those engagements were successful, and most of the ones that did succeed involved corporate governance or climate change issues. Most CSR efforts with individual companies lasted about 1.5 years, they found.

The study also found the asset manager targeted public companies that were large, older firms that care about their reputation, Karakas said. CSR interactions helped the companies achieve better operating performance, profitability, efficiency and governance, he added.

"These engagements do seem to create value," Karakas said.

--Dorothy Hinchcliff