Replication Data for: Public response to government alerts saves lives during Russian invasion of Ukraine

War is the cause of tremendous human suffering. To reduce such harm, governments have developed tools to alert civilians of immi nent threats. Whether these systems are effective remains largely unknown. We study the introduction of an innovative smartphone application that notifies civilians of impending military operations developed in coordination with the Ukrainian government after the Russian invasion. We leverage quasi-experimental variation in the timing of more than 3,000 alerts to study civilian sheltering behavior, using high-frequency geolocation pings tied to 17 million mobile devices, 60% of the connected population in Ukraine. We find that, overall, civilians respond sharply to alerts, quickly seeking shelter. These rapid post-alert changes in population movement attenuate over time, however, in a manner that cannot be explained by adaptive sheltering behavior or calibration to the signal quality of alerts. Responsiveness is weakest when civilians have been living under an extended state of emergency, consistent with the presence of an alert fatigue effect. Our results suggest 35-45% of observed civilian casualties were avoided because of public responsiveness to the messaging system. Importantly, an additional 8-15% of civilian casualties observed during the later periods of the conflict could have been avoided with sustained public responsiveness to government alerts. We provide evidence that increasing civilians’ risk salience through targeted government messaging can increase responsiveness, suggesting a potential policy lever for sustaining public engagement during prolonged episodes of conflict.

战争是人类深重苦难的根源。为减轻此类伤害，各国政府已开发出面向平民的迫近威胁预警工具。然而此类系统的有效性在很大程度上仍未得到验证。我们针对一款创新智能手机应用展开研究：该应用由乌克兰政府在俄罗斯入侵乌克兰后联合开发，可向平民通报即将开展的军事行动。我们借助超过3000次预警发布时间带来的准实验变异，结合绑定1700万台移动设备的高频地理位置ping数据（覆盖乌克兰60%的联网人口），分析平民的避难行为。研究发现，整体而言平民会对预警做出显著响应，迅速前往避难场所。但预警后人口流动的此类快速变化会随时间逐渐衰减，且该衰减模式无法通过适应性避险行为或对预警信号质量的校准加以解释。当平民长期处于紧急状态时，响应性最弱，这与预警疲劳效应的存在相符。我们的研究结果显示，由于公众对该预警系统的响应，已观测到的平民伤亡中避免了35%-45%。重要的是，若在冲突后期能够持续保持公众对政府预警的响应，还可额外避免8%-15%的已观测平民伤亡。我们的研究提供证据表明，通过针对性的政府宣传提升平民的风险感知度，能够增强其响应性，这为长期冲突场景下维持公众参与提供了潜在的政策抓手。