Border control is the implementation of border controls on travel between Svalbard, which maintains a policy of free migration as a result of the Svalbard Treaty (Norwegian: Svalbard-traktaten; ) and the Schengen Area, which includes the rest of Norway. The Kingdom of Denmark also maintains a complex system of subnational countries with autonomous customs policies, since they aren’t within the European Union like the Danish mainland. These are Greenland () and the Faroe Islands (). These areas do not maintain strict immigration controls with the Schengen Area, but border controls are sporadically enforced for customs purposes. Other examples of effective internal border
Greenland a tight fiscal policy since the late 1980s, which has helped create surpluses in the public budget and low inflation. Since 1990, Greenland has registered a foreign-trade deficit following the closure of the last remaining lead and zinc mine that year. More recently, new sources of ruby in Greenland have been discovered, promising to bring new industry and a new export from the country. (See Gemstone industry in Greenland). Air transportation exists both within Greenland and between the island and other nations. There is also scheduled boat traffic, but the long distances lead to long travel times and low frequency.