The article deals with neighborhood ties to European Union countries in terms of graph theory. It is determined the minimum distance between states and the consequences, in terms of minimum distance, of leaving the European Union by one country or another.

Analysis carried out on macro-regions and counties reveals a disproportionate development of areas of Romania, with growth rates of GDP high in Bucharest-Ilfov, but and Gorj, Arad and Timis and very low, even negative in the nearby counties of Arges, Giurgiu Prahova and Teleorman indicating many...