In the first part of the course we learnt that if we allow market forces to work we reach an efficient outcome: the maximum benefit that can be generated by a market. The second part of the course explores cases where the markets fail to accomplish our goals. This week sets up the benchmark case of the perfectly competitive market: a model we will modify in the next few weeks. We define Perfect Competition, learn to model it graphically and discuss some key results in terms of long run profits and implications for efficiency.

A monopoly is a case where there is only one firm in the market. We will define and model this case and explain why market power is good for the firm, bad for consumers. We will also show that society as a whole suffers from the lack of competition.

Monopolies come in various types: one price monopoly, natural monopoly, price discrimination and monopolistic competition. This week we will expand the basic monopoly model to cover these cases and then explore market outcomes in each case. We will also discuss how government may intervene in such cases to benefit society as a whole and increase the surplus generated by the market.

Two classic cases of market failure will be defined and explored: externalities and public goods. We will define each case, demonstrate why the market fails to provide the efficient outcome and suggest interventions through either marked design or regulation.