Management Science · 2025 · Vadim Elenev、Luis Quintero、Alessandro Rebucci、Emilia Simeonova
中文摘要
本文考察了新冠疫情初期美国各县为遏制疫情而交错实施的居家令（SHOs）对人口流动造成的直接效应与溢出效应。我们发现，相邻县的流动下降幅度为实施居家令各县的三分之一到一半。此外，这些溢出效应集中于与处理县共享媒体市场的县。利用方向性流动数据，我们还发现，在流动总量的整体下降中，邻县内部流动的下降所占比例远大于源自处理县的出行减少所占比例。综合来看，这些结果为居家令通过信息共享与自愿保持社交距离发挥作用提供了有力证据。基于我们的估计结果与一个简单的居家令交错实施模型，我们构建了反事实情景，将政策协调的影响与实施时点的影响区分开来。我们发现，交错实施居家令所带来的流动下降幅度，可能大于协调但延迟实施居家令的情形。
Abstract
This paper investigates the direct and spillover effects on mobility caused by the staggered adoption of stay-at-home orders (SHOs) implemented by U.S. counties to contain COVID-19 at the beginning of the pandemic. We find that mobility in neighboring counties declines by a third to a half as much as in the counties that implement the SHOs. Furthermore, these spillovers are concentrated in counties that share media markets with treated counties. Using directional mobility data, we also find that declines in internal mobility in the neighbor counties account for a much larger proportion of the overall decline in mobility than decreases in traffic originating in the treated counties. Together, these results provide strong evidence that SHOs operate through information sharing and voluntary social distancing. Based on our estimates and a simple model of staggered SHO adoption, we construct counterfactual scenarios that separate the impact of policy coordination from that of adoption timing. We find that staggered implementation of SHOs could yield mobility reductions that are larger than coordinated but delayed SHO adoption.