Mitigating Natural Disasters through Collective Action: The Effectiveness of Tsunami Early Warnings

The megathrust earthquake centered near Sumatra on December 26, 2004, generated a tsunami that resulted in an estimated 150,000 deaths in Indonesia alone. In response, commitments have been made to extend the existing tsunami early warning systems in the Pacific to the remainder of the world subject to tsunamis. Surprisingly, while these systems have been in place in some cases for more than half a century, to date no analysis of their effectiveness has been presented. We fill this research gap by analyzing 146 out of the 202 tsunamis occurring worldwide since 1966. Relying on a negative binomial regression model that controls for the dynamics of the tsunami, we find early warnings to be quite effective in reducing deaths. The model also controls for additional factors important in determining a tsunami's death toll such as socioeconomic conditions, which have been shown to be important in other natural disasters.