People would move their income streams into non-$ denominations, keep their bank accounts in foreign currencies and so on to avoid the inflationary effect. Fur

People would move their income streams into non-$ denominations, keep their bank accounts in foreign currencies and so on to avoid the inflationary effect. Further, it would be a regressive tax, not even flat, in practice: poor people are more reliant on cash and short term income which can't be diverted to a different currency. And even if high income people couldn't switch currency, flat taxes are already regressive on a marginal utility basis. Every extra dollar of income or wealth has less utility, because you no longer need to cover essentials like shelter and food, but are spending on entertainment, higher and higher quality, or Veblen goods, etc.