I’ve read several places that Ronald Reagan instinctively understood supply-side economics because Hollywood stars sooner or later learned that making more than a couple of movies per year was pointless when marginal tax rates were 90 percent. The same thing happens in sports. I’ve already posted about soccer stars turning down contracts in places where tax rates are high. Now we have a fascinating little story about taxes and the boxing profession:
For a very long time, boxing was the only really big-money sport for athletes. …At a time when Babe Ruth was being razzed for his $80,000 salary (more than the President of the United States, it was pointed out, to which Babe supposedly replied in 1930, “Well, I had a better year than he [President Hoover] did”), heavyweight champion Jack Dempsey made about nine times as much—over $700,000, for his unsuccessful title defense against Gene Tunney in 1926. …The 1950s was the era of the 90 percent top marginal tax rate, and by the end of that decade live gate receipts for top championship fights were supplemented by the proceeds from closed circuit telecasts to movie theaters. A second fight in one tax year would yield very little additional income, hardly worth the risk of losing the title. And so, the three fights between Floyd Patterson and Ingemar Johansson stretched over three years (1959-1961); the two between Patterson and Sonny Liston over two years (1962-1963), as was also true for the two bouts between Liston and Cassius Clay (Muhammad Ali) (1964-1965). Then, the Tax Reform Act of 1964 cut the top marginal tax rate to 70 percent effective in 1965. The result: two heavyweight title fights in 1965, and five in 1966.
http://www.theatlantic.com/culture/archive/2010/04/how-taxes-changed-boxing/38949/