The Tragedy of the Commons in Mutualistic Networks

Serguei Saavedra 

Wednesdays@NICO Seminar, Noon, November 17 2010, Chambers Hall, Lower Level

Dr. Serguei Saavedra, Northwestern University


The architecture of mutualistic networks facilitates coexistence of individual participants by mini-mizing competition relative to facilitation. However, it is currently unknown whether this benefit is received by each participant in equal portions or it is commensurate with their contributions. Yet, this fact is important to understanding the trade-offs faced by individuals when becoming part of a network. Here we address these questions by applying a novel measure of a node's contribu-tion to network architecture to an ensemble of ecological and socio-economic mutualistic net-works. We find that, paradoxically, individual contributions to the collective are inversely associ-ated with their survival in the network. Individuals in cooperative networks face a critical dilemma of whether to contribute more to increase the persistence of the network or contribute less to selfishly increase their own chances of survival .Our results illustrate how the tragedy of the commons is manifested in heterogeneous networks of mutual cooperation.  


Serguei is a post-doctoral fellow at NICO and Kellogg School of Manage-ment. He joined NICO after obtaining his PhD in Engineering Sciences from Oxford University and working as a post-doctoral fellow at the Said Busi-ness School. His work has been focused on understanding the ecology of collective human behavior. He follows a multidisciplinary approach that combines ecological research, network theory and statistical physics to ana-lyze the cooperative and competitive patterns among individuals. physics to analyze the cooperative and competitive patterns among individuals.