Do all roads lead to Sapporo? The role of linking and bridging ties in evacuation decisions

Abstract

Why do some communities evacuate long-distances in higher rates than others after disaster? This mixed-methods study uses a new dataset of long-distance evacuation rates after Hokkaido’s Eastern Iburi Earthquake in September 2018, aggregated to the city level from geolocated Facebook user movement. We found that communities with stronger linking and bridging social capital tended to see much lower evacuation rates to distant towns. We used statistical models, fieldwork, and content analysis of 12 interviews, finding that despite rumors on social media, communities with stronger linking social networks had greater trust in government and decided to stay in local evacuation shelters. This was especially the case if these communities also had stronger bridging social networks, helping them access key information, especially among vulnerable communities. Meanwhile, residents with weaker linking or bridging networks may have believed rumors of extreme water, food, and power shortages and left town for good. This study highlights the importance of trust in local officials when managing evacuation after disasters.