The graph shows the market for Covid vaccines at equilibrium at a price of $25 and a quantity of 15 million vaccines. Suppose the External benefit from each vaccine is estimated to be $10.

Draw the social benefit curve (Dsocial). You can draw the graph on paper and upload an image. Find the socially optimal Q (Qsocial). What policy would internalize this externality? Internalizing the positive externality means making those who generate positive externality take into account the external benefits of their actions.

Price 12 11 10 9 8 7 6 5 4 3 2 Sprivate D 3 6 9 12 15 18 21 24 27 30 Millions of Gallons per day