Informing Mitigation of Disaster Loss through Social Media: Evidence from Thailand

Abstract:

This paper is the first to investigate the role of online information and social media in enabling households to reduce natural disaster losses. The historic 2011 Bangkok flood is utilized as a case study to assess how internet use allowed households to mitigate flood losses. This event was one of the first major disasters to affect an urban area with a substantial population connected to social media. The role of online information is investigated with a mixed methods approach, using both quantitative (propensity score matching and multivariate regression analysis) and qualitative (in-depth interviews) techniques. The study relies on two data sources – survey responses from 469 Bangkok households and in-depth interviews with internet users who are a subset of the survey participants.

Propensity score matching indicates that social media use enabled households to reduce mean total losses by 37%, using a nearest neighbor estimator. Average loss reductions amounted to USD 3,708 to USD 4,886, depending on the matching estimator. In addition, regression analysis suggests that social media use is associated with lower flood losses (average reduction of USD 2,784). These reductions are notable when considering that total flood losses in 2011 averaged USD 4,903. Social media offered information that was not available from other sources, such as localized and nearly real-time updates of flood location and depth. With knowledge of current flood conditions, Bangkok households could move belongings to higher ground before floodwaters arrived. These findings suggest that utilizing social media users as sensors could better inform populations during natural disasters, particularly in locations that lack real-time, accurate flood monitoring networks. Therefore, expanded access to the internet and social could especially be useful in developing countries, ungagged basins, and highly complex urban environments. There is also an enormous opportunity for disseminating government disaster communication through social media. Overall, the study reveals that online information can enable effective disaster preparedness and reduce flood losses.