Can polycentric urban development simultaneously achieve both economic growth and regional equity? A multi-scale analysis of German regions

Polycentric urban regions have been advocated for, and justified as enhancing both economic growth and overall competitiveness while also creating more equitable and balanced metropolitan regions. We examine the role of regional polycentricity in effectuating certain desirable outcomes, specifically enhancing economic productivity and minimizing spatial disparities simultaneously in German urban regions ( Großstadtregionen) as a case study. Using econometric analysis of both functional and morphological polycentricity measures, our results indicate that polycentric development can effectively reduce regional disparities in urban regions, but not simultaneously promote economic productivity. These findings confirm previous studies that progress toward one goal hampers progress toward another. Further investigation at a finer scale suggests that the borrowed size effect is essentially a “win-loss” game between peripheries and urban core(s) within the same urban region. Peripheries benefit from the spillovers generated by nearby urban core(s), thereby narrowing regional economic gaps and leading to more equitable regions. However, the gains of the peripheries are canceled out by the losses of the urban cores, and polycentric development has an insignificant overall effect on regional economic productivity.