Do we need cash? Humans have used all sorts of things to exchange items of economic value — rare metals, strings of shells and even jugs of whiskey. Those objects have gotten more ephemeral, with paper money replacing most coins, and digital forms increasingly supplanting paper. Could physical cash go away entirely? Economists see great payoffs in a cashless society: lower transaction costs, new tools to manage economic growth and an end to tax evasion and money laundering. Critics see an erosion of privacy, frightening new powers for tyrants and an increase in inequality.