Business owners in Greenfield, Mass., are concerned about a proposed ordinance that would ban plastic bags at grocers and other retailers. The ban would increase costs as retailers switch to paper bags, which can cost as much as four times more than plastic bags, says Matthew Deane, co-owner of Foster's Super Market. "We should be teaching and encouraging people to recycle," Deane said. "There are recycling containers for plastic bags at some stores. That is another option."