• Data reference period
• Geographic localization (Portugal)

• TOTAL POPULATION:  All persons, national or foreign, who are permanently settled in the economic territory of the country, on a given date, even if they are temporarily absent from it.
• GROSS DOMESTIC PRODUCT:  Final result of the production activity of resident producer units and it can be defined in three ways: production approach, expenditure approach and income approach.
• ECONOMIC TERRITORY:  Territory that consists on: (a) the geographic territory administered by a government within which persons, goods, services and capital move freely; (b) any free zones, including bonded warehouses and factories under customs control; (c) the national air-space, territorial waters and the continental shelf lying in international waters, over which the country enjoys exclusive rights; (d) territorial enclaves (i.e. geographic territories situated in the rest of the world and used, under international treaties or agreements between States, by general government agencies of the country (embassies, consulates, military bases, scientific bases, etc.); (e) deposits of oil, natural gas, etc., in international waters outside the continental shelf of the country, worked by units resident in the territory as defined in the preceding subparagraphs.
• REFERENCE PERIOD:  Period to which the information refers and which may be a specific day or a time interval (month, fiscal year, calendar year, among others).

Sum of the absolute differences between regional (NUTS 3 level) and national GDP per inhabitant, weighted by the regional share of population.