Elisa Giannone, a Princeton economist, found in a recent working paper that from 1940 to 1980 the wage gap between poorer and richer cities in the United States converged at an annual rate of 1.4 percent — but that on average there has been no such convergence since then.

Enrico Moretti, an economist at the University of California, Berkeley, has done extensive work arguing that the divergence has roots in the rise of more technologically intensive industries combined with the offshoring of lower-skilled work, such as manufacturing. Many of the thriving areas are places where these technologically advanced companies and their employees cluster.

In what is surely a related pattern, Joseph Parilla and Mark Muro of the Brookings Institution found that not only are there big differences in the productivity of different regions — how much economic output is generated per worker — but that the high-productivity regions are also pulling away from the low-productivity ones.

This body of work — focused on how differences in regional economies can explain broader challenges — is attracting more notice from economists and policymakers who have tended to look at things from a national perspective. They’re realizing it may not be enough to worry about overall levels of G.D.P. or employment or wages, when those headline numbers can mask big problems.

“Convergence used to be the order of the day,” said Larry Summers, the Harvard economist and former Treasury secretary. “Now if anything divergence is the order of the day. There’s a lot more to understand, but at a minimum we need to start recognizing place as a legitimate construct in our thinking.”

Mr. Summers, known for his work on macroeconomics, began arguing around the time of the 2016 election that economics researchers needed to start taking regional divides more seriously as a contributor to bigger problems. To that end, he recently wrote a paper with his Harvard colleague Edward Glaeser, a leading scholar of urban and regional economics, and Benjamin Austin that examined how the rising rate of nonemployment among prime-aged men in parts of the American heartland had fed into social dysfunctions.