Kinetic theory for the emergence of complex behavior in social and economic systems

Decentralized sharing norms for managing risk in uncertain environments

Athena Aktipis

Arizona State University

Throughout history, humans have managed the risks associated with living in uncertain environments through a variety of means including pooling risk. The Maasai of East Africa deal with this problem with a need-based transfer system called osotua (literally, umbilical cord) that leads to a pooling of risk among participants. Similar systems have been documented elsewhere. Previous models demonstrated that this system leads to greater viability of herds under the volatile ecological conditions in which the Maasai live. We implement the osotua asking and giving rules on a network in order to understand which network features promote herd survival. We also examined the features of survival networks in order to understand the characteristics of the networks that result from 50 simulated years of osotua sharing under ecologically volatile conditions and the elimination of individuals who do not stay above sustainability threshold. Finally, we examine whether need-based transfer rules can outperform reciprocity rules in ecologically realistic conditions.