How many people don’t have a bank account? And just how difficult has it become to live without one? These questions are becoming increasingly important as more businesses refuse to take cash in cities across the U.S. People without bank accounts are shut out from stores and restaurants that refuse to accept cash. As it happens, a lot of people are still “unbanked”: roughly 6 million in the U.S., the latest data shows, which is about the population of Wisconsin. And outside of the U.S., more tha...