Some regulations make the market less free, some make it more free. Many free markets degrade into oligopolies and eventually monopolies unless they are regulat

Some regulations make the market less free, some make it more free. Many free markets degrade into oligopolies and eventually monopolies unless they are regulated. Free market economics is something you learn on the first day of economic theory. But then you very quickly learn that they don't actually exist or if they did exist would be very bad for us (due to high external costs etc.) In what market do consumers really have perfect knowledge? Which markets really have no barriers to entry? Some economists argue that the existence of marketing and advertising immediately defeats any hope of a free market.