Alex Tabbarok tries to explain inequality in terms of globalization- and technology-driven superstar effects, citing JK Rowling's billion dollar earnings as an example. He notes that a Homer or a Shakespeare could only sell their wares to relatively tiny audiences -- maybe 50 at a time in Homer's case or 3,000 for Shakespeare:

Tolkien's words were leveraged further. Tolkien could sell to hundreds of thousands even millions of buyers in a year - more than have ever seen a Shakespeare play in 400 years - by selling books. And books were cheaper to produce than actors which meant that Tolkien could earn a greater share of the revenues than did Shakespeare (Shakespeare incidentally also owned shares in the Globe.)

Rowling has the leverage of the book but also the movie, the video game, and the toy. And globalization, both economic and cultural, means that Rowling's words, images, and products are translated, transmitted and transported everywhere - this is the real magic of Ha-li Bo-te.

To me, there's no question that this kind of thing is going on. International superstars across fields now have a global customer base that allows the very most popoular -- most popular writers, musicians, baskteball players, hedge fund managers, lawyers, oncologists, etc. -- to earn windfalls far beyond the dreams of mortals. And insofar as this is a large part of the inequality story, it does tend to undercut highly moralized objections to the right being so darn rich. Rowling isn't doing anything wrong to get so rich. But on the other hand, insofar as this story is right, it also seems to me that the primary pragmatic worries one might have about pro-equality measures likewise tend to melt away. If the very best in a range of fields are just bound to reap enormous windfall earnings under current technological conditions then it seems unlikely that tax measures aimed at limiting the size of those windfalls would significantly deter anyone from doing their work. One doubts Rowling set about down this path because she thought it stood any reasonable chance of making her a billionaire.