Ding, Parwada, and Shen (2014)

Ding, Ning, Jerry T. Parwada, and Jianfeng Shen.  “When does a stock boycott work? Evidence from a clinical study of the Sudan divestment campaign.”  Working paper (University of New South Wales - Australian School of Business), 2014.

From the authors' abstract:  "[We] examine the effectiveness of an international stock boycott by studying a large sample of institutional investor transactions in four emerging market stocks targeted by the Sudan divestment campaign from 2001 to 2012. We find evidence of a negative relationship between the intensity of the campaign and the ownership breadth of the stocks. However, selling by institutional investors is only observed in the U.S., where the campaign operates from. Further, higher campaign intensity is associated with depressed stock prices and thus higher future returns."

Link:  http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2469575