According to this article in the WSJ, "corporate gadflies," defined as individual investors who repeatedly file similar proposals among a number of companies, were responsible for a third of shareholder proposals through May 30. So concludes a study by Proxy Monitor of 212 of the largest (by revenue) publicly traded U.S. companies. In second place were investors with a religious, socially responsible or public policy agenda, sponsoring 29% of proposals. Labor-affiliated pension funds accounted for 25% of all proposals, down sharply from 35% last proxy season and putting them in third place. The study reported only one proposal –removal of a poison pill -- from "traditional" institutional investors. According to the article, "the studied companies were subjected to an average of just under 1.2 shareholder proposals each. That figure has been relatively stable since 2011, following rules for mandatory ‘say on pay' votes."