The Evolution of U.S. City Size Distribution From a Long-Term Perspective (1900-2000)*

This paper analyses the evolution of city size distribution in the United States throughout the twentieth century. It tests the validity of two empirical regularities studied in urban economics: Zipf's law (the rank-size rule), and Gibrat's law, or the law of proportionate growth. The main contribution of this work is the use of a new database with information on all the cities (understood as incorporated places), without size restrictions. Our results enable us to confirm that Gibrat's law holds (weakly), and that Zipf's law holds only if the sample is sufficiently restricted at the top, not for a larger sample.