Table of Contents
ISRN Economics
Volume 2014, Article ID 498125, 6 pages
Research Article

Evolutionary Model of the City Size Distribution

EBC Hochschule, Alexanderplatz 1, 10178 Berlin, Germany

Received 17 February 2014; Accepted 12 March 2014; Published 1 April 2014

Academic Editors: J. Le Gallo and E. Yeldan

Copyright © 2014 Joachim Kaldasch. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An evolutionary model of the city size distribution is presented that explains the size of a city from the reproduction process and the migration of humans between cities. The model suggests that the city size distribution is a lognormal distribution with a power law tail in agreement with empirical results and computer simulations. The main idea of the model is that the competition between cities in the migration process is the origin of Gibrat's law. While growth rate fluctuations generate the lognormal branch of the size distribution, the power law tail for large cities is caused by a small mean growth rate.