LeBron James and the staggering "gender gap" in professional basketball

Sometimes, a little anecdote or example can be so powerful. For example, public school teachers send their kids to private schools at well more than the national average. Or if you can't come close to stopping drugs in prison, how are you going to stop them in a "free" society.

Here's a great one from Mark Perry on profound gender income inequality in pro basketball. 

Even when people push for equal pay, it's unequal. For example, in tennis at Wimbledon, men and women champs are paid the same. But the men have to play many more sets to get the same money. Once you get away from the market, you just get some trade-offs-- many of them unsavory, unfair, and inefficient.