Even assuming the absence of hyper-inflation, I wouldn’t endorse a 70% tax rate. The mistake is explained thus.
Say you make great money as a surgeon: about $400,000 per year. you could make more, even, but when you contemplate the 70% rate starts at $350,000, everything you do after that $350,000 is diminishing returns. Bobby’s brain tumor will just have to wait.
Same goes with every other business in America: once you his the point of diminishing returns, it’s time to quit and go the the summer house.