Private monopoly vs public monopoly

The most sane (albeit not against a very high standard) of a number libertarian (or, at any rate, very pro-market) bloggers in Britain that I read, admits that network effects mean that many markets tend to “collapse” into monopolies. I would add that many more markets tend to become oligopolies or cartels. In the face of this, why does he still believe that leaving everything to the markets is the best way to run an economy? Continue reading