Graphing Oligopolies

Please understand that the MC curve can cross through the space between the two marginal revenue curves.  Simply by following the line straight up to the demand curve, we still get the price.  None of our rules change because we are dealing with a new graph.  Profit maximization still occurs when MR=MC. 

Game Theory

Tax and Subsidy: Per Unit and Lump Sum

This video deals with the affects taxes or subsidies have on the firms in the different market structures.  Addressed here is the use of both per unit and lump sum taxes or subsidies with a few examples.  At home, please practice a per unit and lump sum tax and subsidy on each market structure (perfect competition, monopolistic competition, monopoly, and oligopoly).

Monopolistic Cometition

This video discusses the Monopolistic Competition model in the short-run and in long-run equilibrium.  In addition excess capacity and dead weight loss is discussed in the context of efficiency. 
The Monopolistic Competition model is relatively difficult to draw so make sure you practice at home.