Simulating disaster volunteerism in Japan: “Pay It Forward” as a strategy for extending the post-disaster altruistic community

When a large disaster occurs, many volunteers can be garnered. After the Tohoku Earthquake in Japan in 2011, about 1.4 million volunteers rushed to the disaster area. Survivors-turned-volunteers from the 2004 Chuetsu Earthquake helped people in Noda Village, which was affected by the 2011 Tohoku Earthquake and Tsunami, while in turn people affected by the Chuetsu Earthquake were assisted by survivors of the 1995 Kobe Earthquake from Nishinomiya City. Such a chain of support is called a “Pay-It-Forward” Network (PFN) and can serve as a valuable reserve of volunteer support in the next disaster. This paper studies PFNs using mathematical simulation and cellular automata. First, we compare two variables: whether volunteerism tended to be affected by neighborhoods ( N ) or by a disaster itself ( R ) following two large disasters in Japan: the 2011 Tohoku Earthquake and the 1995 Kobe Earthquake. Second, we simulated volunteerism in the 1995 Kobe Earthquake and the 2011 Tohoku Earthquake using cellular automata, including changing the variables ( α ) reflected by sympathy based on similar disaster experience. We found that the neighborhood ( N ) factor prevented the PFN from triggering inter-survivor support especially in the Tohoku case; however, the simulation revealed that, under other conditions, the PFN can spread volunteerism dramatically. On the whole, this study suggests the importance of two factors, N and R , and shows that PFNs can effectively activate the chain of support in some cases.