Defining and measuring polycentric regions: the case of Tuscany

Polycentric development in regions has many dimensions, which involve several definitions and measures. This paper tackles the problem of defining and measuring polycentricity under an integrated and multi- dimensional perspective. Firstly, the policy relevance of polycentricity is analysed. Then, the paper identifies the definitions and measures of polycentricity by surveying the literature. It also provides a taxonomy among two main aspects involved in the definition of polycentricity: the morphological dimension and the functional dimension. Based on this background, an empirical analysis is carried out, by using data about population and commuting flows in the Tuscany Region (Italy). The results show that Tuscany can be viewed as a polycentric spatial structure, both considering rank-size distribution of cities and spatial interaction.