Beyond Population: Migration Flows as a Complement to Agglomeration in Urban Economic Scaling

DOI

10.2991/978-94-6239-787-3_79How to use a DOI?

Keywords

urban scaling law; intercity migration; economic output; Cobb-Douglas production function

Abstract

The urban scaling law establishes that denser social interactions within cities drive the superlinear scaling of economic output with population size. However, the role of exogenous intercity population flows in shaping this relationship remains poorly understood. Using 409 U.S. Metropolitan Statistical Areas (MSAs), we integrate in-migration and out-migration into the urban scaling framework and show that the population scaling elasticity declines markedly—from 1.119 to 0.507–0.662—once migration is accounted for, indicating that intercity mobility is a substantive complement to internal agglomeration in driving superlinear economic scaling. Shapley decomposition further reveals that migration collectively explains over 63% of GDP variance, rivalling the contribution of population size alone. Extending the model to a transcendental logarithmic specification, we identify significant positive synergies between population size and migration flows, with larger cities yielding disproportionately higher marginal economic returns to migration. A two-way fixed-effects panel model corroborates these patterns dynamically: population elasticity remains stable at 1.27–1.37 and the positive effect of in-migration persists after controlling for industrial structure, human capital, and innovation. Together, these findings integrate the dual dynamics of internal agglomeration and external connectivity into urban scaling theory, with implications for regional development strategies that leverage intercity migration networks.

Copyright

© 2026 The Author(s)

Open Access

Open Access This chapter is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), which permits any noncommercial use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.

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TY  - CONF
AU  - Jiayao Li
AU  - Liang Gao
PY  - 2026
DA  - 2026/09/29
TI  - Beyond Population: Migration Flows as a Complement to Agglomeration in Urban Economic Scaling
BT  - Proceedings of the 2026 4th International Conference on Management Innovation and Economy Development (MIED 2026)
PB  - Atlantis Press
SP  - 814
EP  - 821
SN  - 2352-5428
UR  - https://doi.org/10.2991/978-94-6239-787-3_79
DO  - 10.2991/978-94-6239-787-3_79
ID  - Li2026
ER  -