The relative efficiency of ad valorem and unit taxes is analyzed for oligopolistic markets. We provide a simple proof that ad valorem taxes welfare-dominate unit taxes in the short run if production costs are identical across firms. The proof covers a wide range of market conduct and...

We analyze the incidence of ad valorem and unit excise taxes in an oligopolistic industry with differentiated products and price-setting (Bertrand) firms. Both taxes may be passed on to consumers by more than 100 percent, and an increase in the tax rate can increase short run firm profits (and...

This paper analyzes the incidence of ad valorem and unit excise taxes under imperfect competition with differentiated products and price-setting (Bertrand) firms. Both taxes may be overshifted onto consumers, and a higher tax rate can increase short run firm profits (and hence the long run...