Any externalized cost that you tolerate as regulator is already an indirect form of subsidy in my view. E.g. allowing a mining company to dump tailings in the n

Any externalized cost that you tolerate as regulator is already an indirect form of subsidy in my view. E.g. allowing a mining company to dump tailings in the next river is exactly the same as paying for proper disposal with tax money (from a company finances point of view). So any untaxed air polluter/CO2 emitter enjoys an indirect subsidy already. But in the french case, farmers and fishermen got paid 15-30 cents per liter on top (removing all ambiguity).