An avalanche of empirical studies has addressed the validity of the rank-size rule (or Zipf's law) in a multi-city context in many countries. City size in most countries seems to obey Zipf's law, but the question under which conditions (e.g. sample size, spatial scale) this 'law' holds remained...

This study was prepared by Andreas Kuhlmann, while he was working with the Ifo Institute for Economic Research. It was completed in September 2006 and was accepted as a Ph.D. thesis by the Economics Department of the University of Munich. The subject of this study is the analysis of network...