French politician Jean-Luc Mélenchon has suggested limiting the profits of fuel refiners in response to a sharp rise in fuel prices, which have surged since the start of the energy crisis. According to Eric Dor, director of economic studies at the IÉSEG School of Management, up to 13 cents per liter of the increased fuel cost can be attributed to higher refining margins. Mélenchon argues that by capping these margins, consumers could see several cents per liter saved on their fuel bills. Fuel prices have risen significantly since February 27, with the average price of SP95 gasoline increasing from 1.708 to 2.151 euros per liter—an increase of 44.3 cents. Of this, 32 cents are due to the rising cost of crude oil, which accounts for 72% of the total increase. The refining margin, which is the profit a refinery makes after processing crude oil, has also risen, from 5.4 to 16.5 cents per liter. This contributes 11.2 cents to the price of SP95. For diesel, the increase is even more pronounced, with 46.5 cents of the 68.2-cent rise coming from crude oil and 12.7 cents from the refining margin. However, the gross refining margin—what a refinery earns before expenses—is not the same as net profit. Refineries must cover costs like salaries, energy, maintenance, and carbon emissions. Eric Dor estimates that while operating costs have risen slightly, most of the increase in refining margins is likely profit. According to industry data, the physical refining margin for diesel on the Amsterdam-Rotterdam-Antwerp market rose from 45 to over 91 dollars per barrel between June and September. Capping refining margins in France faces practical challenges. Fuel prices are determined by a European market, and setting lower prices in France could lead foreign suppliers to sell fuel elsewhere where prices are higher. France imports about half of its diesel and 10% of its gasoline, with only seven major refining plants in mainland France. While the government could legally regulate prices or margins for companies operating within its borders, it cannot control foreign refineries. Additionally, France has no influence over global oil prices, which are determined by international markets. An alternative to capping margins is to tax the extra profits made by French refineries and redistribute the money to motorists. However, this would also have limitations, as France cannot tax profits from foreign refineries that supply much of its fuel. Other European countries have taken steps to control fuel prices, but these generally focus on limiting the commercial margins added by distributors, not the refining process itself. Countries like Croatia, Albania, and Slovakia have implemented their own mechanisms, but none directly target the profits of refiners.