Deliniation of metropolitan areas in Poland: A functional approach

elineation of urban functional areas helps policymakers and urban planners understand the connections between the core cities and areas surrounding them, and subsequently develop policies and solutions that can serve local populations. This article develops a readily applicable econometric method for delineation that considers functional aspects of cities and their surroundings. We perform delineation analysis using the data for 78 Polish core cities, grouping them by population size. Using the satellite data on lights emitted at night, population density, commuter numbers as well as the number of houses and apartments built in each commune, we apply a threshold regression model to determine the boundaries of functional urban areas. Our main results suggest that the mean radius of functional urban areas (FUAs) around the largest (most populous) cities is, on average, 21 km, while it is between 13 and 16 km for smaller cities. We then test how the econometric results compare with the perceptions of local inhabitants through a citizen science project (CSP) conducted as a robustness check.