Mayor Vincent Gray vetoed a bill on Thursday that would force Wal-Mart Stores and other large retailers to pay their employees at least $12.50 an hour. http://www.nytimes.com/2013/09/13/business/bill-to-raise-retail-wages-in-dc-gets-mayors-veto.html?ref=us The bill put Washington at the center of a national debate on how far cities should go in trying to raise pay for low-wage workers — and whether […]