To Mr. Galenson markets are what make the 20th century completely different from other eras for art. In earlier periods artists created works for rich patrons generally in the court or the church, which functioned as a monopoly. Only in the 20th century did art enter the marketplace and become a commodity, like a stick of butter or an Hermès bag. In this system, he said, breaking the rules became the most valued attribute. The greatest rewards went to conceptual innovators who frequently changed styles and invented genres. For the first time the idea behind the work of art became more important than the physical object itself.

Economists, of course, have turned their attention to the art world before. Thorstein Veblen, in his 1899 classic, “Theory of the Leisure Class,” discussed how the newly moneyed turned everything, including art, into elements of conspicuous consumption. But over all, economic theories of art are still relatively rare.

In the preface to his 2000 book “Creative Industries,” the Harvard economist Richard E. Caves said that decades earlier he had come up with the idea but “thought it best postponed to a time when my reputation for professional seriousness could more comfortably be placed at risk.”

In 2002 Mr. Galenson discussed his theories about creativity in the book “Painting Outside the Lines.” Then, two years ago, he published “Old Masters and Young Geniuses: The Two Life Cycles of Artistic Creativity,” arguing that young innovators have a flash of inspiration that upends the existing order in an instant. There are old geniuses too, he said, but their approach is vastly different. They are what he labeled “experimentalists,” who develop their work gradually through years of trial and error.

His theory of creativity was based in part on examining auction prices. His approach was hailed by some as a breakthrough, and this spring he was awarded a Guggenheim fellowship to pursue his research.