> However, economies of scale do not imply the monopolist should produce a large quantity of output
I know, I know. I assume that the natural monopoly is required by law to have maximum price=MC. According to this video such regulation would require constant subsidies for monopoly, because otherwise it will go bankrupt:
https://www.coursera.org/learn/microeconomics-part2/lecture/VWpuW/3-1-6-natural-monopoly-regulation-though-marginal-cost-pricing
I know how a monopoly maximizes its profit. I'm just suprised that at P=MC its accounting profit would be negative, while a competitive firm can survive under P=MC without subsidies.