A study by the Cologne Institute for Economic Research has investigated how severely the income per head in a country would be hit if it had to survive without its capital.
The results showed that across Europe, capital cities were the focal points of their countries’ economies.
This "capital city effect" shows that in France there'd be a 15 percent drop in the French output per capita without Paris.
This is a higher rate than in every other European country besides Greece, which would see a 19.9 percent drop in GDP.
The Paris effect on France has "a pronounced impact", the study noted, and can partly be explained by the fact that nearly a fifth of all French people live in the Ile-de-France region that includes Paris.
This population is responsible for a third of the country's gross domestic product.
Other European countries that were strongly dependent on their capitals included the Czech Republic, which was 14.2 percent worse off without Prague, Portugal, which saw a 13.7 percent drop without Lisbon, as well as Denmark, Finland and Sweden (all around the 12 percent mark without their capitals).
Brits, meanwhile, would be 11 percent poorer without the financial muscle of London.
Germany was a notable exception on the list, actually seeing a 0.2 percent increase in GDP without Berlin.
France was among eleven EU member states that recorded a level of GDP per capita above the EU average in 2015.
With a GDP per capita of 106 (against the EU average of 100), France ranked 11th in the union.