Studies on optimal fuel tax rates with distortions of the consumption tax and the income tax

考虑到消费税和所得税的扭曲，分析了降低道路运输外部成本的最优燃油税税率。至于所得税的扭曲，最优燃油税税率往往更高，因为提高燃油税税率降低了交通拥堵的成本，降低了所得税税率。另一方面，当消费税或燃油税上调时，尽管消费税和燃油税的比例发生了变化，但包含在所有税种中的“最优”燃油价格并没有太大变化。

I analyzed the optimal fuel tax rates to reduce externalcosts of road transportation with considering distortions ofthe consumption tax and the income tax. As for distortions of the income tax, the optimal fuel tax rate tends to be higher, because raising fuel tax rates reduces the cost of traffic congestions and it cuts the income tax rate. On the other hand, when the consumption tax or the fuel tax is raised, the “optimal” fuel price that includes of all taxes does not change so much, though the proportion of the consumption tax and the fuel tax changes.