Ever since Bitcoin exploded onto markets, governments around the world have been exploring how to digitize their currencies. A total of 87 countries representing over 90 percent of global GDP are researching, piloting, or deploying central bank digital currencies (CBDCs): digital versions of official paper money. Their goals are varied and include ensuring the primacy of official money over unwanted cryptocurrencies, improving the efficiency with which people can make payments, and reducing the number of households that rely solely on paper money to provide for their needs. Competition between banks for payment-related services has been relatively weak, and in many...