Roughly three quarters of vehicles are purchased into multi‐car households. We study whether households are willing to substitute attributes, such as fuel economy, across vehicles within their portfolio. We develop a novel strategy to separately identify idiosyncratic preferences for an attribute from these within‐portfolio effects. Using the universe of household vehicle registration records in California over a 6‐year period, we find that two‐car households exhibit strong substitution across vehicles when faced with an exogenous change to fuel intensity of a kept vehicle. This effect can erode a substantial portion of the benefit from major policies, such as Cash‐for‐Clunkers.

中文翻译：

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家用车辆组合中的属性替换

大约有四分之三的汽车被购买到多车家庭中。我们研究了家庭是否愿意在其投资组合中的车辆之间替代诸如燃油经济性等属性。我们开发了一种新颖的策略，可以从这些组合内效应中分别识别属性的特质偏好。通过使用加利福尼亚州6年间的家庭用车注册记录，我们发现，两辆车的家庭在面对保存的车辆的燃料强度的外在变化时，在车辆之间表现出强大的替代性。这种影响会侵蚀主要政策（例如旧车换现金）的大部分收益。