Northwestern Bulgaria, the southeastern area of ​​Strandzha-Sakar, the western region of Kraishte and the Central Stara Planina are turning into "demographic deserts," Assoc. Prof. Nadezhda Ilieva of the Bulgarian Academy of Sciences has told the "Horizont" program of the Bulgarian National Radio. The study "Regional Demographic Imbalances in Bulgaria" forecasts that by 2040 the population of Bulgaria will be 5 - 5.2 million people. 1/4 of the settlements will be depopulated. 37% of the villages will have up to 20 inhabitants. 69% of the territory of Bulgaria will fall in the category of "demographic desert".

Overcrowded areas will be Sofia, the Plovdiv-Pazardzhik region and the axes of urbanisation around Burgas and Varna. "In the coming decades competition will focus on population. Those cities that managed to attract more people would survive," Ilieva said.