How does e-shopping impact household travel? To answer this question, which is particularly relevant for policymakers concerned with congestion, air pollution, and greenhouse gas emissions from transportation, we analyzed data from the 2017 National Household Travel Survey using propensity score matching. This allowed us to tackle the bias from households self-selecting into various levels of e-shopping and gain causal inference. Unlike other related papers in the literature, our unit of analysis is a household because travel and shopping decisions within a household are interrelated. We classified households into three groups based on how many orders per person per month they placed online: low (up to one), medium (more than once but less than four), and high (over four). We found that more e-shopping results in more household travel (number of trips, miles, and VMT), but this effect depends on e-shopping frequency and population density, and it affects weekdays more than weekends. -shopping impacts household travel more for medium frequency e-shoppers in low density areas: compared to similar low frequency e-shoppers, on weekdays, they take on average 8 more monthly trips and travel ∼104 extra miles (including 31 miles for shopping). At the other end of the spectrum, high frequency e-shoppers in dense areas do not travel more on weekends than similar low e-shopping frequency households. To help reduce e-shopping induced travel, policymakers could encourage the creation of neighborhood depots where households would pick-up and return unwanted orders, and foster the development of virtual reality tools for shopping from home.

中文翻译：

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网购会影响家庭出行吗？2017 年美国 NHTS 的证据

网上购物对家庭出行有何影响？为了回答这个与关注交通拥堵、空气污染和温室气体排放的政策制定者尤其相关的问题，我们使用倾向得分匹配分析了 2017 年全国家庭旅行调查的数据。这使我们能够解决家庭自我选择不同级别的电子购物的偏见并获得因果推断。与文献中的其他相关论文不同，我们的分析单位是家庭，因为家庭内的旅行和购物决策是相互关联的。我们根据每人每月在网上下的订单数量将家庭分为三组：低（最多 1 个）、中（多次但少于 4 个）和高（超过 4 个）。我们发现，更多的电子购物会导致更多的家庭旅行（出行次数、里程和 VMT），但这种影响取决于电子购物频率和人口密度，并且它对工作日的影响大于周末。-购物对低密度地区中频网购者的家庭出行影响更大：与类似的低频网购者相比，工作日平均每月出行次数多 8 次，多行驶约 104 英里（其中购物 31 英里） 。另一方面，密集地区的高频电子购物者周末出行并不比类似的低电子购物频率家庭更多。为了帮助减少电子购物引起的旅行，政策制定者可以鼓励建立社区仓库，让家庭可以提取和退回不需要的订单，并促进在家购物的虚拟现实工具的开发。