Indirect Taxation in Vertical Oligopoly
研究了上下游均为寡头且可自由进入的行业中，从量税和从价税的效果，发现下游征收从价税更有效，且仅通过从价税筹集税收更优，同时给出了间接税改善福利的条件。
This paper analyzes the effects of specific and ad valorem taxation in an industry with downstream and upstream oligopoly and endogenous entry in both layers. We find that it is typically more efficient to levy an ad valorem tax downstream than upstream, while it is immaterial on which layer a specific tax is levied. We also show that tax revenues should be raised only through ad valorem taxes. Furthermore, we provide conditions under which the introduction of an indirect tax improves welfare. From a total surplus perspective, excise taxes tend to appear in a less favorable light when the full vertical supply chain is considered compared to a partial analysis which only takes into account market power at one layer. Finally, we demonstrate that a tax tends to be shifted to a larger extent into the final consumer price in vertical oligopoly than in standard oligopoly.