The Carpathian Hills are considered the zone of original Romanian settlement. In fourteenthand fifteenth-century Moldavia and Wallachia the market-oriented grain trade transformed kin relations, fostered ownership of some villages and regions, and spawned population shifts to lowland plains. Romanians remaining in uplands established villages extending along river bottoms in a dispersed pattern. Urban centers were populated extensively by non-Romanians; Greeks and Turks in the south, Magyar and German speakers in Transylvania and Banat (the southwest), Jews and German speakers in Bucovina (the northeast). A western European commercial class was found throughout the country as well. Socialist development has encouraged more balanced rural-urban Population distribution. Regional settlement patterns are now undergoing great change, with attempts at social engineering occurring via the policy of systemization. Under this policy, less populous villages are razed, larger villages developed into towns servicing a network of villages, and major cities closed to most new immigration. Restrictions are also placed on rural construction. New peasant homes must be two stories for multifamily occupancy, and apartment construction has been greatly expanded. Systemization has recently been intensified. Out of 13,000 villages, 7,000 are to be razed, with the affected population to be moved elsewhere.