They're not, really. They lend themselves to monopolies and oligopolies, and lead to high levels of capital concentration and thus income inequality. Government

They're not, really. They lend themselves to monopolies and oligopolies, and lead to high levels of capital concentration and thus income inequality. Government intervention is required to correct this, but hasn't in over 40 years. I'm more or less making an appeal to authority to Piketty here but, people generally agree with him.