Zipf's law and city size distribution: A survey of the literature and future research agenda

This study provides a systematic review of the existing literature on Zipfs law for city size distribution. Existing empirical evidence suggests that Zipfs law is not always observable even for the upper-tail cities of a territory. However, the controversy with empirical findings arises due to sample selection biases, methodological weaknesses and data limitations. The hypothesis of Zipfs law is more likely to be rejected for the entire city size distribution and, in such case, alternative distributions have been suggested. On the contrary, the hypothesis is more likely to be accepted if better empirical methods are employed and cities are properly defined. The debate is still far from to be conclusive. In addition, we identify four emerging areas in Zipfs law and city size distribution research including the size distribution of lower-tail cities, the size distribution of cities in sub-national regions, the alternative forms of Zipfs law, and the relationship between Zipfs law and the coherence property of the urban system. (C) 2017 Elsevier B.V. All rights reserved.