“…The latter region, together with certain districts in northeast and southern Bulgaria, has the lowest degree of urbanisation, the highest share of elderly people in the population, and the largest population decline due to emigration [32]. These areas cover 10 out of the 28 Bulgarian districts that have lost at least 20% of their population over the last two decades [33]. By contrast, the southwest region, which covers Sofia (the capital) as well as the districts of Blagoevgrad, one of Bulgaria's most significant, economic, educational, and cultural centres beside the capital [28], shows strong urbanisation and agglomeration effects with an increasing population [33].…”