Facing Scale, Space, and Time in Population Ageing: Tales from the Italian Laboratory

Population ageing is reshaping demographic structures across advanced economies. Italy, with one of the most aged populations globally, represents a particularly relevant case. This paper investigates the evolution of the spatial distribution of people aged 75 and over between 1991 and 2021, adopting a multiscale approach that combines national census data for all Italian municipalities with inequality and spatial autocorrelation measures. First, we apply the Theil entropy index to evaluate how the spatial distribution of the older population diverges from that of the total population. Its decomposition, aligned with Italy’s administrative hierarchy, shows that inequality has gradually shifted from macro-territorial divides to within-province variation. Second, we analyse local ageing intensity using the municipal share of residents aged 75 and over. Despite decreasing aggregate inequality, global and local spatial autocorrelation statistics reveal strong and persistent spatial clusters that continue to shape the national pattern. High-ageing clusters have expanded across inland and mountain areas; low-ageing clusters persist in major urban and metropolitan regions. Overall, the findings indicate that population ageing is now a pervasive national phenomenon, yet its spatial imprint remains deeply structured and locally resilient.