External shocks embody an unexpected and disruptive impact on the regular life of people. This was the case during the COVID-19 outbreak that rapidly led to changes in the typical mobility patterns in urban areas. In response, people reorganised their daily errands throughout space. However, these changes might not have been the same across socioeconomic classes leading to possibile additional detrimental effects on inequality due to the pandemic. In this paper we study the reorganisation of mobility segregation networks due to external shocks and show that the diversity of visited places in terms of locations and socioeconomic status is affected by the enforcement of mobility restriction during pandemic. We use the case of COVID-19 as a natural experiment in several cities to observe not only the effect of external shocks but also its mid-term consequences and residual effects. We build on anonymised and privacy-preserved mobility data in four cities: Bogota, Jakarta, London, and New York. We couple mobility data with socioeconomic information to capture inequalities in mobility among different socioeconomic groups and see how it changes dynamically before, during, and after different lockdown periods. We find that the first lockdowns induced considerable increases in mobility segregation in each city, while loosening mobility restrictions did not necessarily diminished isolation between different socioeconomic groups, as mobility mixing has not recovered fully to its pre-pandemic level even weeks after the interruption of interventions. Our results suggest that a one fits-all policy does not equally affect the way people adjust their mobility, which calls for socioeconomically informed intervention policies in the future.

翻译：外部冲击对人们的正常生活具有不可预测且具有破坏性的影响。COVID-19疫情迅速改变了城市地区典型的移动模式。对此，人们重新安排了日常活动在空间上的分布。然而，这些变化在不同社会经济阶层之间可能并不一致，导致疫情可能加剧不平等问题。本文研究了外部冲击导致的移动隔离网络重组，并表明疫情期间流动性限制的实施影响了人们在访问地点（包括地理位置和社会经济属性）上的多样性。以COVID-19疫情为自然实验，我们分析了多个城市在外部冲击下的即时效应、中期效应及残余效应。基于对波哥大、雅加达、伦敦和纽约四座城市的匿名且隐私保护的移动数据，结合社会经济信息，我们捕捉了不同社会经济群体在移动中的不平等现象及其在不同封锁阶段（之前、期间及之后）的动态变化。研究发现，首次封锁显著加剧了各城市的移动隔离，而放松限制并未必然减少不同社会经济群体之间的隔离，即使在干预措施解除数周后，移动混合程度也未完全恢复至疫情前水平。我们的结果表明，"一刀切"政策并未平等影响人们调整移动方式的行为，这提示未来需制定基于社会经济差异的干预政策。