https://macropaperwarehouse.com/authors/hansen-shao/Hansen ShaoHugo -- gohugo.ioen-ushttps://macropaperwarehouse.com/papers/the-dynamics-of-internal-migration-a-new-fact-and-its-implications/https://macropaperwarehouse.com/papers/the-dynamics-of-internal-migration-a-new-fact-and-its-implications/<p>Howard and Shao document a new empirical regularity in U.S. internal migration: the t-year interstate migration rate — defined as the share of people living in a different state than they did t years ago — is approximately proportional to the square root of t. The fact is established using the Gies Consumer and Small Business Credit Panel (GCCP), a 15-year panel (2004–2018) covering approximately 1 percent of all Americans with a credit report, and is corroborated in the Panel Survey of Income Dynamics (PSID, 1969–1997), where the square root pattern holds out to a 25-year horizon. The fact is not an artifact of averaging across origins, destinations, cohorts, or age groups: most of the distribution across these cuts is concentrated close to the square root line. It holds for both people under 45 and over 45, and is robust to the choice of time period and inter-state distance.</p>