Mountain communities face the threat of depopulation, as residents age or move to large cities in the lowland. This issue is pressing for Italy, where a large portion of the territory is mountainous and the overall population is rapidly aging. This paper analyses whether the autonomous status of a region affects the demographic dynamics of its mountain areas. The question is currently being fiercely debated in Italy, with border municipalities seeking to switch region in pursuit of perceived benefits, mainly in the form of the direct management of a larger portion of taxes. The analysis relies on an adjacency-based estimation approach, including spatial regression discontinuity techniques, to compare population changes in mountain areas randomly selected from Northern Italian regions with special statutes versus neighboring regions without special statute. Measuring population changes in the 2000s shows a significant difference in the demographic dynamics in border regions, with areas in autonomous regions experiencing more favorable population dynamics. Our hypothesis is that fiscal autonomy contributes to sustainable local development and the survival of mountain communities.