Air safety certification could be seen as a market, with the buyers being localities (towns, cities, city-states, counties, etc). I don’t think the issue is so

Air safety certification could be seen as a market, with the buyers being localities (towns, cities, city-states, counties, etc). I don’t think the issue is so much “markets vs govt” as it is accountability vs impunity. The issue with single-payer, nationalized air protection is that there’s a single point of failure and there’s no reasonable means of individual dissent (pulling funding, voting with one’s feet, etc). Of course this line of thinking leads to some very politically incorrect conclusions.