Geographies in flux - how time and location influence shrinking medium-sized cities

Urban shrinkage has emerged as a significant challenge across Europe, particularly for medium-sized cities (MSCs) with populations between 20,000 and 100,000. While previous research has largely focused on demographic decline in large cities, the spatial and institutional dynamics of shrinkage in MSCs remain underexplored. This study offers a comparative, longitudinal analysis of MSCs in Germany and Poland, two countries with different urban systems and planning traditions. Drawing on a harmonised shrinkage score composed of six demographic and socioeconomic indicators, the paper investigates spatial patterns over 15 years (2003–2018 for Germany; 2006–2021 for Poland). Spatial tools, including Moran's I, k-means clustering, and multivariate regression, are used to explore how proximity to large and metropolitan cities, as well as regional context, influences city trajectories. Results show that in Poland, shrinkage has intensified over time, particularly in the southern and eastern regions, while growth is concentrated around a few large urban centres. In Germany, spatial patterns are more stable: growth is concentrated in the southwest and around metropolitan areas, while shrinkage remains moderate but geographically selective. Multivariate models reveal that proximity to large cities (in Poland) and metropolitan centres (in Germany) negatively correlates with shrinkage scores, but regional structures and governance contexts explain more variation. The study identifies six MSC typologies and highlights the need for spatially and institutionally differentiated planning approaches. By integrating spatial and statistical methods across national contexts, this paper contributes to a more nuanced understanding of urban shrinkage as a territorially embedded and governance-dependent process.