From Statistics Explained
The economic territory of a country consists of the geographical territory administered by a government. Within this area, people, goods and capital may circulate freely. Economic territory includes the land and also the national air space, territorial waters, natural deposits of oil and gas in international waters (if worked by resident units), and territorial enclaves abroad, such as diplomatic representations and military bases. It excludes extra-territorial enclaves, that is the parts of a country's own geographic territory used by, for example, diplomatic representations of foreign countries or of the European Union’s institutions.