[quote="TheTrueCentrist, post:18, topic:286301"]
Certainly there do exist government-granted monopolies. However to say that market capitalism is immune to them is willfully ignorant of historical examples.
I would ask this "What makes a company successful in a market capitalism?" The answer is large profits. How can a company guarantee large profits? By gaining a monopoly. Essentially, a monopoly is the unspoken goal of any company in a free market. Moreover, in a sufficiently free market, political power is a commodity like any other.
And in a perfect world, things would work perfectly. However, the market system all but designed to create people with greater buying power than others, and as you so strongly emphasized: "the greatest threat to human freedom is the concentration of power."
Your close to what makes a company successful is large profits, but it's not right. The goal of any firm is to maximize profits, namely for the owner, so that the owner has a no opportunity cost - it's the best way to make money with his own time and money.
Having large profits is not necessary for this to be true. As long as the company is as profitable to the owner as the next best opportunity (this, by theory, could be a the same as compared to, say, the best career he could get), then it's enough for the company to remain in business.
EDIT: Actually, you don't even need that much. You just need for the marginal revenue to cover the variable costs. Otherwise, the business shuts down (at least temporarily).
The reason a monopoly can form boils down to a few assumptions, with the primary being Barriers to Entry/Exit:
1) Government Regulation (Ex. Patents)
2) Economy of Scale (More you make, cheaper it is, but before to long, Diseconomies of Scales, which is the effect of a large overhead, etc. comes into effect, allowing competition to remain more competitive)
3) Indivisibility (I can't think of an honest example)
4) Control of essential input (Ex. De Beers)
Over time, without government regulation, or control of essential input, monopolies will fall to a competitive market.
I'm willing to say the #1 reason for any monopoly, present or past, is because of government regulation.