Does Compactness Matter? Comparative Study of Medium‐Sized Shrinking Cities’ Compactness in Germany and Poland

Urban shrinkage is an increasingly pressing phenomenon in Europe, affecting medium‐sized cities that are vital to regional stability. However, large‐scale, longitudinal research on the relationship between urban form characteristics and shrinkage remains limited. This study examines whether urban compactness influences the trajectory of shrinking cities by comparing all medium‐sized cities (20,000–100,000 inhabitants) in Germany and Poland over 15 years. Using geospatial tools and multi‐criteria indicators, we quantify urban shrinkage through a composite score and assess urban form compactness based on CORINE Land Cover data, employing two measures: urban population density and the Schwartzberg compactness index. Pearson’s correlation analysis is used to examine how the relationship between urban shrinkage and compactness evolves over time. The findings indicate that medium‐sized German cities show a clear and consistent negative correlation between urban shrinkage and the two compactness measures throughout the period. In other words, the more compact and dense a medium‐sized city is, the less likely it is to shrink. Polish cities exhibit more mixed trends. The correlation results show that there is a temporal positive coefficient between shrinkage and density, but a negative correlation between compactness measures and shrinkage. Overall, results suggest that urban compactness, among other factors, can play an important role in medium‐sized cities’ shrinkage management. This study identifies patterns in medium‐sized cities in both countries regarding compactness and shrinkage trends, supporting cross‐national knowledge exchange and the development of context‐sensitive planning strategies.