Consider Figure 9.15, denoting the demand curve in a given market as well as a series of cost curves: (private) average total cost (ATC ), marginal private cost (MPC ), and marginal social cost (MSC ). Indicate (in words and using the points from A to P that you deem appropriate) the area corresponding to the deadweight loss resulting from the externality.

p Demand A M ATC MSC MPC D B G E H 0..2 F P q FIGURE 9.15 Externality and welfare loss