let's suppose a firm is currently maximizing its profit;that is,given a market price MR, it is producing q* units as suggested by figure 9.17. assume further that a tax is added to each unit sold. Because the firm must pay the government the amount of the tax for each unit sold,the marginal cost to the firm of each unit increases by the amount of the tax.Geometrically,that means the marginal cost curve shifts upward by the amount of the tax.Assume for the moment that the the entire industry is able to increase the market price by simply adding on the amount of the tax to the price of each unit.