@Justinian
"The free-market will take care of most monopolies and oligopolies on its own."
There is no free market. There never has been.
By this illustration, I show a 100% free market scenario, 100% pure competition, where there is no scarcity of any good or service. Imagine a town where every single person is just as capable of providing any service imaginable as any other person. Also, every person has the power to simply manifest any good they or their customer might want simply by visualizing it. This is a scenario in which there is perfect competition, where the only commodity, ultimately, is the visualizer's time. Now because everyone equally capable of the task, everyone's time would end up being equal in value.
By contrast, another illustration shows a 100% free market scenario with less than 100% pure competition: imagine another town in which, like previously, anyone could visualize any product, but not everyone is equally capable of providing services. For instance, anyone could visualize a hammer and lo and behold in say 5 minutes of visualizing, but not everyone would be as skilled as everyone else in using said hammer. In this scenario, then the ability to perform brain surgery might only be had by say 3 doctors in town. Conversely, there are 2000 people who are capable of using a hammer well - doing construction work or general labor. As such, the construction worker's time would tend to be worth less than the brain surgeon's. But it is not only because of the relative scarcity of their respective skill, but also because demand of the skill: for example, if the demand for new houses were high enough, the 2000 construction worker's time might be worth more than the doctor's time if demand for brain surgeries were low. The illustration, then, is to show how even in a society in which there were no scarcity of goods, but relative scarcity and demand of skills, the value of the laborer's time, be the laborer a doctor or a construction worker, is set according to supply of and demand for their respective skills.
Thus, putting aside the supply and demand for goods and considering only the supply and demand for services, what would happen if the 2000 construction workers or the 3 doctors were to form a union or association and set their wages regardless of supply and demand? What if the 3 doctors were to form a single office and agree to charge the same fees regardless of demand. What if the construction workers demanded higher pay than the market value as set by supply and demand? Would this be a "free market" system any longer? What if every profession did such? What if there was something called a "minimum wage" set regardless of supply and demand? What if the value of people's labor was no longer determined by supply and demand? How would that world look like?
Well, it is not a hypothetical world. It is reality, and everybody know this, and yet so many claim there are free market principals at work?
And the fact is, that such wages and salaries are regulated, often inflated in one economy and / or undervalued in another, and the scarcity of skills is manipulated by conglomerates of governmental regulatory bodies, associations, unions, academic institutions, etc. - all manipulations conducted behind the scenes to suit, ultimately, the tax-advantaged ELITE.
These wages and salaries are set regardless of demand, and because there is usually only one major association or union per profession, they hold virtual monopolies on the SKILLS of entire service-based industries, sabotaging any sort of 'free market' as determined by supply or demand.
Next, consider how prices of goods are effected by the manipulated cost of services, AND how the price of goods themselves are ALSO manipulated. Look at how it is many services which produce the goods for markets and thereby provide for an inflated or undervalued price; look at wheat boards, OPEC, corporate conglomerates; look at the regulatory bodies of various industries which manufacture goods, and the laws that prevent small businesses from being able to compete with larger ones; look at the costs of starting up manufacturing enterprises that might be even remotely competitive. You'd need billions of investment to start one up. You think somebody in his garage can start an assembly line that can produce a car that can compete with Toyota?
It is a system designed to prevent innovation; designed to prevent competition.
Wake up.
There's no free market - never has been one.
You cannot expect free market processes to sort out the problems with virtual monopolies and oligopolies if those monopolies and oligopolies are subverting the "free market" processes you expect will sort out the problem!