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RWP 21-02, May 2021; updated July 2023

Metropolitan areas are a fundamental unit of economic analysis, but official U.S. delineations stray egregiously from the conception of them as unions of built-up lo-cations within which people regularly travel among places of residence, employment, and consumption. We develop an algorithm that uses commuting flows among cen-sus tracts to match varied interpretations of this conception. The resulting family of metropolitan delineations exhibits four characteristics: Population probability distributions decline over their entire domain. They are also too bunched at the top relative to the bottom to be consistent with a Pareto benchmark. Land proba-bility distributions peak at an intermediate size. And land area increases less than proportionately with population, with an implicit elasticity that declines further be-low 1 with size. The land-population relationship suggests that centripetal forces, such as centralized employment and centralized amenities, constrain metropolitan expansion.

JEL Classification:  R12, R23, R41

Article Citation

  • Humann, McKenzie, and Jordan Rappaport. 2021. “The Size of U.S. Metropolitan Areas.” Federal Reserve Bank of Kansas City, Research Working Paper no. 21-02, May. Available at https://doi.org/10.18651/RWP2021-02

Author

Jordan Rappaport

Senior Economist

Jordan Rappaport is a senior economist at the Federal Reserve Bank of Kansas City. He joined the Bank in 1999 following completing his Ph.D. in economics at Harvard University. J…