We don’t yet know who agreed to pay $179.4 million for a Picasso in an auction Monday night — or where the money came from, or what motivated that person or persons to spend more than anyone has before for a single piece of art at auction.

But this much we do know: The astronomical rise in prices for the most-sought-after works of art over the last generation is in large part the story of rising global inequality. At its core, this is the simplest of economic math. The supply of Picasso paintings or Giacometti sculptures (one of which sold for $141 million in the same auction this week) is fixed. But the number of people with the will and the resources to buy top-end art is rising, thanks to the distribution of extreme wealth.

One of the most important findings of the leading economists who study inequality is that wealth and incomes at the very top are “fractal.” What they mean is that when you zoom in on the upper end of wealth distribution, patterns repeat themselves in an ever more finely grained pattern.

Partners at law firms who are in the top 1 percent of all earners have seen their incomes rise faster than successful dentists who are in the top 10 percent. But by a similar margin C.E.O.s of large companies who are in the top 0.1 percent are seeing incomes rise faster than those law firm partners. Hedge fund managers in the top 0.01 percent are similarly outperforming the C.E.Os.