The Ile de France - essentially Paris and its suburbs and satellite towns - has an economy that is 50 per cent larger than the next wealthiest EU region, which is Lombardy in northern Italy.
Greater London comes third but its gross domestic product is put at pounds 120bn a year, only just over half that of the Ile de France (pounds 220bn). Greater Paris has a population of 11,000,000; Greater London 7,000,000.
The study is unusual because it ignores the usual method of expressing regional wealth in terms of GDP per head: total, annual earnings divided by population. On that basis, the Ile de France comes only fifth, behind Hamburg, Brussels, Frankfurt and Luxembourg (but still well ahead of Greater London).
The report, produced by the French statistical institute INSEE, seeks to draw a map of Europe based on concentrations of raw economic power, not the wealth of individuals. On this basis, the greater Paris region stands head and shoulders over all other regions.
Only one other French region - Rhone-Alpes, the area around Lyons and Grenoble - comes in the top 10. Italy has two (the Milan and Rome regions), Germany three (North Rhine-Westphalia, Hesse and Bavaria) and Britain and Spain one each (Greater London and Catalonia). The other region to make the top 10 is the whole of Denmark.
As much as anything else, the study reveals the enormous centralisation of French economic power. The greater Paris region accounts for 25 per cent of the economic production of the country (and 5 per cent of the GDP of the European Union).
The annual economy of the Ile de France is double the size of that of Austria. Other countries have greater disparities between regions in terms of GDP per head but only France has such a concentration of economic power in the centre.
The Ile de France, which extends about 50 miles to the east, west and south of Paris and about 30 miles to the north, is far from uniformly rich. It contains some of the most depressed and violent inner-suburban housing estates in France. It also includes satellite towns such as Mantes and Evry, which have high unemployment and some of the worst social and racial problems in the country.
But it also comprises almost all France's banking and other financial industries, much of the high-tech business and some of the wealthiest and most productive cereal farms in the world (EU subsidies permitting).
The study points to the fact that, with a few exceptions such as the rising economic power of Ireland, the disparities between European regions appear as great as ever.
The economic backbone of the European Union - sometimes called the "blue banana" - stretches from London to northern Italy via Belgium, Frankfurt, Munich and Paris.
The poorest EU region, in terms of absolute GDP, is the sparsely populated Ahvenanmaa-Aland in Finland.
Greece provides five other regions in the bottom 10, Britain none and France one (Corsica).Reuse content