Now that's ironic.
I love how Rothbardian purists talk about this mythical anarcho-capitalist theoretical paradise that has never existed, ever. Not even close. Reminds me of communist purists.
Accountable to shareholders? First, shareholders have no say other than to sell their shares. All other talk about shareholder rights and activism is just more fantasy. Corporations are totalitarian dictatorships. But somehow just because it isn't called "government", it's all good in the eyes of some. It doesn't matter if you label it a powerful "government", "corporation" or "religion", it's all the same. Power corrupts.
With mutual funds, index funds and retirement trusts, most people don't even know what stocks they own. Sure, corporations may be held accountable to these super-shareholders, but those super-shareholders are nothing more than other huge corporate entities, who have been proven not to have the best interests of the small investors.
America has certainly represented one of the best examples of open and competive markets, but to put on blinders and ignore corruption, abuse of power, oligopolies, collusion and totalitarianism because it isn't labeled "government" is overly idealistic, and will lead to more concentration of power and abuse.
What? I'm hardly an idealogue or an anarcho capitalist - government provides law and order, which is a valuable service, and is one of the primary reasons why our financial system is so sound and why our economy is generally stable and prosperous when compared with 99.9% of economies, present and historical. I'm not talking about some ideal, im actually criticizing the ideal put forth by the poster im responding to - i'm actually talking in realistic terms when i say that setting prices below marginal cost (i.e. at a loss) would not happen in business, and one of the reasons i cited was that it would piss off peolpe who hold equity in the company. If a company operates at at a real loss for each unit of production, it will be leaked, and there will be a massive windfall, probably in the form of share-dumping, and it would only be exacerbated when it comes time to report earnings. I know i would no longer invest in a company that was operating at a severe loss for an extended period of time, and most if not all mutual fund managers will eliminate a high-loss corporation from the fund's portfolio, since it is their job to return a high yield for their investors. The total equity of the company would fall so much that any gained market share would probably be lost quickly, and the value of the company would actually go down, and there would be no money to reinvest in growth, and the company would have to return to raising prices above marginal costs... in this timeframe, one has to assume that every other single competitor goes bankrupt for the idea of the natural monopoly based on price-fixing to work. There is such thing as monopolistic price-setting, but it is not precluded by below-cost price fixing. THAT is the real fantasy.
Could a natural monopoly, by the economic definition, ever occur? I wouldnt go as far as many libertarians say it could NEVER, EVER, by the laws of economics, happen. It certainly good with the right conditions, perhaps. What i am challenging is both microeconomic fallacies, and historicial inaccuracy by designating certain companies, such as Standard Oil, as monopolies, or even monopolistic in practice. There has not been a natural monopoly (by the real definition, not the political bitch-fest one) in the (short) history of market capitalism, but that doesnt mean its a matter of induction, whereby it will "never happen" because it hasn't before; simply, it hasn't, and just making up some scenario of how a firm could gain a monopoly is an exercise in futility, especially when riddled with flaws in the economic reasoning.
I will say that natural resources pose a unique problem, but generally the choice is between large multinational corporations, or even larger state-owned/controlled entities - lots of small petroleum companies would probably just jack prices up futher, since the refining process is already at almost maximum-efficiency by each of the big oil companies, due mainly to their large size and economies of scale (and scope), thus size and consolidation are beneficial to consumers in the industry.