发表机构
Northeastern University; New York University（东北大学; 纽约大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究利用大规模流动性数据，证明基于流动性网络而非地理距离定义暴露能更准确评估城市政策效应，发现免费票价和开放街道计划显著提升活动，而拥堵定价仅转移活动而非减少，强调政策影响需通过流动性衡量。
AI 中文摘要
城市政策评估通常假设其效应随地理距离衰减。然而，城市是人口流动的系统，政策效应通过个体流动性而非仅空间邻近性传播。本研究证明，忽视流动性会系统性地扭曲对城市政策影响活动的估计。利用大规模流动性数据，我们使用传统地理和基于流动性的暴露定义，估计了波士顿和纽约市三项交通干预的因果效应。地理设计未检测到效应，甚至检测到负面效应。当通过流动性网络定义暴露时，相同的干预措施揭示了显著的行为变化。波士顿的免费票价计划使整体活动增加约16%，在低收入社区中效果更为显著。开放街道计划显著增加了对附近企业（尤其是餐饮场所）的访问量。对于拥堵定价，地理方法表明曼哈顿活动减少，而基于流动性的视角则表明没有净减少，但购物和杂货目的地发生转移。对八个国家138个大都市区的进一步分析显示，在每个城市中，地理和流动性网络距离在局部均存在差异，表明这种差异是城市流动性的普遍特征。总体而言，这些发现表明，城市政策不仅在其实施地点发挥作用，还在人们移动的地点和方式中发挥作用，因此其影响必须通过流动性而非空间来衡量。
英文摘要
Urban policies are often evaluated assuming their effects decay with geographic distance. However, cities are systems of human movement, and policy effects propagate through individual mobility rather than spatial proximity alone. This study demonstrates that neglecting mobility can systematically distort estimates of how urban policies affect activity. Using large-scale mobility data, we estimate the causal effects of three transportation interventions in Boston and New York City using both conventional geographic and mobility-based definitions of exposure. Geographic designs detect no effects, or even negative ones. When exposure is defined through mobility networks, the same interventions reveal substantial behavioral change. Boston's free-fare program increases overall activity by approximately 16%, with more pronounced effects among lower-income communities. Open Streets programs significantly increase visits to nearby businesses, particularly food establishments. For congestion pricing, geographic approaches suggest a decline in activity in Manhattan, while a mobility-based perspective indicates no net reduction but a shift away from shopping and grocery destinations. Analysis across 138 metropolitan areas in eight countries further reveals that geographic and mobility-network distances diverge locally in every city, indicating that this discrepancy is a general characteristic of urban mobility. Collectively, these findings show that urban policies operate not only where they are implemented but where and how people move, so their impact must be measured through mobility rather than through space.
Comments52 pages, 25 tables, 14 tables
