Spatial Analysis of Urban Growth in Spain

In this paper we examine the cross-sectional distribution of population in Spain and its evolution for the period 1998-2019. To do this, we estimate a Zipf's Law over the set of urban municipalities by means of several econometric models with spatial effects. In addition, we also run several specifications to test the validity of the rank-size rule, and we end up finding that a quadratic relationship is satisfied. Consequently, we also revise the growth process of the Spanish urban system testing for the Gibrat's Law, and we conclude that the reason for a concave Zipf's Law is that municipalities have not grown homogeneously in space during the period. Finally, we used the Spatial Gini Index and Markov processes to uncover the true underlying trends of the distribution of the population over time, finding evidences of a catching-up process at the intra-cluster level while a divergent one at the national level, both strongly spatially dependent.