Pacifying Babel's Tower: A scientometric analysis of polycentricity in urban research

It is sometimes claimed that the degree of polycentricity of an urban region influences that region's competitiveness. However, because of widespread use and policy relevance, the underlying concept of polycentricity has become a stretched concept' in urban studies. As a result, academic debate on the topic leads to situations reminiscent of Babel's Tower. This meta-study of the scientific literature in urban studies traces the conceptual stretching of polycentricity using scientometric methods and content analysis. All published studies that either apply the concept directly or cite a work that does, were collected from the Scopus bibliographic database. This resulted in a citation network with over 9000 works and more than 20,000 citations between them. Network analysis and clustering algorithms were used to define the most influential papers in different citation clusters within the network. Subsequently, we employed content analysis to systematically assess the mechanisms associated with the formation of polycentric urban systems in each of these papers. Based on this meta-analysis, we argue that the common categorisation of polycentricity research in intra-urban, inter-urban and inter-regional polycentricity is somewhat misleading. More apt categorisations to understand the origins of polycentricity's conceptual ambiguity relate to different methodological traditions and geographical contexts in which the research is conducted. Nonetheless, we observe a firm relation across clusters between assessments of polycentricity and different kinds of agglomeration economies. We conclude by proposing a re-conceptualisation of polycentricity based on explicitly acknowledging the variable spatial impact of these different kinds of agglomeration economies.