What is clean air worth? What do you pay for it? In the US, you pay taxes which are distributed under the purview of a democratic republic, whose officials may decide to create an EPA, which may enforce rules, etc. Tautologically, clean air is now worth something in the US, because the system pays for it. But it wasn't the case 100 years ago. Or in another timeline where Nixon didn't create the agency. It's worth something because the conditions of the system aligned its interest with that outcome, not because of some direct preference of the populace. In many countries, clean air isn't "worth much" because you can't pay for it, even though the people want it badly.