ISE Professor Cynthia Chen presented these findings in a keynote at the 2024 International Conference on Resilient Systems (ICRS) in Singapore.

ISE research reveals local peer-to-peer sharing can dramatically reduce resource shortages during disaster isolation periods.

A new paper co-authored by ISE and CEE (Civil and Environmental Engineering) Professor Cynthia Chen demonstrates that local peer-to-peer (P2P) resource sharing has significant, untapped potential to bolster community resilience in the face of disasters. The paper, published in Nature Cities, stems from a $2 million National Science Foundation (NSF) grant awarded to Professor Chen and her collaborators, including UW professors Dan Abramson from Urban Design and Planning, Kurtis Heimerl from Computer Science and Engineering, Tyler McCormick from Sociology and Statistics and ISE’s Shuai Huang. This research shows the immense power of "neighbor helping neighbor" in times of crisis, offering a powerful and complementary strategy to traditional, top-down government aid.

This research, which involved surveys and simulations in two socio-economically distinct Seattle communities - Laurelhurst and South Park - reveals that place-based P2P sharing could significantly reduce "resilience loss" during a disaster scenario. Resilience loss is defined as the product of the number of households experiencing a resource shortage, multiplied by the number of days they experience the shortage. The study used a simulated 5-day isolation period. This timeframe was chosen because most households are prepared to be self-sufficient for up to seven days.

In this simulated disaster, place-based P2P sharing reduced resilience loss by 13.4% to 100%, depending on the specific resource. The study examined ten essential resources, categorized as either survival resources (food, medication, first aid, warmth, transportation) or infrastructure resources (communications, sanitation, power, shelter). The study found that survival resources had a greater impact on reducing resilience loss than infrastructure resources. For example, place-based P2P sharing was able to completely eliminate resilience loss for food, medication, first aid, warmth, and transportation in both communities.

One of the most compelling findings was that place-based social ties (neighborly relations) are important and even a small number of social ties can make a big difference in a community's ability to share resources effectively. Increasing the number of social connections within a community directly correlates with increased sharing rates and reduced resilience loss. Remarkably, the study found that even a small increase in social ties – approximately 6 per household – can significantly boost P2P resource sharing.

While the study affirmed the importance of both strong and weak social ties, it also highlighted the critical role of strong ties – those with family and close friends – for individual survival during a disaster. Strong ties proved to be 1.5 to 3 times more effective than weak ties (acquaintances) in helping individuals secure the resources they needed to survive.

Part of the community simulation exercise setup to categorize what the community has and needs.

The research also explored whether altering ingrained sharing preferences could enhance resilience. People naturally prefer to share with those they are closest to (strong ties), and then with weaker ties, with strangers being the lowest priority. This study found that while an enforced, "utopian" equal sharing priority – where there is no preference for sharing based on relationship strength – did offer a marginal improvement in resilience, the difference was not significant. This key takeaway suggests that community-based initiatives should focus on strengthening and expanding existing social ties rather than trying to engineer changes to these ingrained sharing behaviors.

Says Professor Chen, "This research reveals the incredible potential of people helping each other during disasters. While government support remains vital, fostering local, peer-to-peer resource sharing can be a truly transformative approach. We can make communities way more resilient by tapping into their inherent strengths, and this study provides a clear path forward."

Professor Chen presented these findings in a keynote at the 2024 International Conference on Resilient Systems (ICRS) in Singapore. Her presentation included research on optimal logistics for P2P sharing, such as determining the ideal number of sharing captains per community block and analyzing P2P sharing effectiveness across different resource availability scenarios. The presentation generated significant interest and led to opportunities for international collaboration.

These findings have broad implications for communities across the United States seeking to improve their disaster preparedness. While the study focused on two distinct Seattle neighborhoods with very different socio-economic profiles, both communities showed similar trends. Laurelhurst is a predominantly white, wealthy, and urban neighborhood, while South Park is a more diverse, lower-income area. Despite these differences, both communities shared similar trends in the potential for P2P sharing, suggesting that the model could be successfully applied in many other communities throughout the US.

ISE Professor and Chair Juming Tang notes, "This work showcases how industrial and systems engineering can tackle pressing societal challenges. Professor Chen and her team have created a practical and impactful roadmap for communities to harness their internal resources and fortify their resilience in the face of growing disaster risks. I am excited to see this research applied to enhance community resilience in Washington and beyond."