Task: Several of you have mentioned that monoplies arise from economies of scale: a particularly interesting issue is the concept of Minimum Efficiency Scale (MES).
Are monoplies necessarily bad?
In what cases are monopolies necessarily evils that are preferable to wasteful competition?
The AT&T situation until its 1984 break-up, or others such as Boeing and Airbus, may give us some useful insights.
Other examples that would be interesting to discuss are the cases in which the government supports the existence of monoplies by giving them exclusives licenses/franchises, and why it makes sense to do so.