As millions of young Americans head back to the classroom this season, the majority of parents are likely waiting until the last minute to start shopping and budgeting for their back-to-school purchases, according to a new poll released by Chase Card Services, a division of JPMorgan Chase & Co., and U.S. News & World Report. The Chase Slate-U.S. News Consumer Monitor found that 55 percent of families have not yet begun their back-to-school shopping, and that, overall, 62 percent of families have not set a budget for back-to-school purchases.