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.