Energy efficiency improvements can create rebound effects that increase energy use. We have studied rebound in US freight transportation and found that substitution across transportation modes can be an important rebound mechanism. The sign of the rebound effect depends on whether the improved efficiency induces substitution with more or less fuel-efficient modes. We used detailed US microdata to model shippers’ freight mode choices and simulate how these choices change under energy efficiency standards. Under a policy approximating US heavy-duty truck fuel economy standards, we found that rebound can be positive or negative in individual market segments. However, the overall effect substantially reduces the gains from improved truck fuel efficiency. Energy savings are reduced by around 20% because shipments switch from rail service to the improved, but still less fuel-efficient, truck service. Similar substitution rebound effects could occur in other settings where producers choose between technologies with different energy efficiencies.

能源效率的提高可以产生反弹效应，从而增加能源使用。我们研究了美国货运的反弹，发现运输方式的替代可能是一个重要的反弹机制。反弹效应的迹象取决于效率的提高是否会导致燃油效率更高或更低的模式的替代。我们使用详细的美国微观数据对托运人的货运模式选择进行建模，并模拟这些选择在能源效率标准下如何变化。在接近美国重型卡车燃油经济性标准的政策下，我们发现个别细分市场的反弹可能是积极的，也可能是消极的。然而，总体效果大大降低了卡车燃油效率提高所带来的收益。由于运输从铁路服务转向改进但燃油效率仍然较低的卡车服务，能源节约减少了约 20%。类似的替代反弹效应也可能发生在生产者在不同能源效率的技术之间进行选择的其他环境中。