Considering that the whole country are market participants and not just the capitalists they can create market rules the same way they can create laws and still be free. The whole belief that the "markets" are apart from society makes no sense.
And this happens because there is a dichotomy; a free society with only one class of participant vs a society with free people and slaves. The marketplace always has at least two classes, buyers and sellers. Buyers are typically those with liquid negotiable assets and sellers those with less liquid / negotiable assets; the most common liquid negotiable asset being cash. So when there is more than one class then there is a much higher probability that one party will have more "power" than the other, cf voters vs representatives in representative democracies, multi-national companies vs individual consumers.
