The Calvert Social Index is a stock market index of companies that are considered socially responsible. It was created by Calvert Investments and uses Calvert’s social criteria to determine whether a company is socially responsible or not. This criteria relates to the environment, product safety, community relations, international operations, weapons contracting, human rights, and workplace issues. While the number changes frequently, as of August 2010, there were over  650 companies in the index.