Understanding metropolitan growth in German polycentric urban regions

The paper investigates the peculiarities of polycentric urban regions (PURs) in generating agglomeration economies, namely, the question of how urbanisation externalities – size, density and diversity – take effect in German PURs and influence the growth of metropolitan functions from 1995 to 2017. The metropolitan growth of PURs is compared with that of urban regions showing a dominant core. We use our findings to address questions about the forces of urbanization externalities on a regional scale. Finally, we outline what we see as emergent research topics in the interplay between metropolization and the development of PURs.