Transportation economists apply different labor supply models when examining transport pricing: (i) endogenous working hours; (ii) endogenous workdays; (iii) labor supply as a residual. We study whether the optimal level of transport taxes that changes the relative cost of labor supply margins is robust against the model applied. We find surprisingly strong differences in the level of optimal fuel and miles taxes and even variation in the sign of the Ramsey terms. For instance, the US and UK optimal fuel taxes vary up to 19% and 15% and the Ramsey terms up to 73% and 130%. Finally, we develop a recommendation for research on all issues that include decisions on commuting trips: Researchers should apply both a model of endogenous working hours and a model of endogenous workdays because the first provides the upper limit and the second the lower limit for optimal tax levels and Pigouvian and Ramsey terms.

运输经济学家在检查运输价格时采用了不同的劳动力供给模型：（i）内生工作时间；（ii）内生工作日；（iii）剩余的劳动力供应。我们研究了可以改变劳动力供给边际成本的最佳运输税水平是否对所采用的模型具有鲁棒性。我们发现最佳燃油税和里程税水平之间的惊人出乎意料的巨大差异，甚至是Ramsey术语符号的变化。例如，美国和英国的最佳燃油税差异最大为19％和15％，拉姆齐条款最高为73％和130％。最后，我们针对所有问题（包括上下班旅行的决策）提出研究建议：