Sunbelt XXXI International Network for Social Network ... - INSNA

The Network Structure Of Competition Between Multipoint RivalsPallotti, Francesca; Mascia, Daniele; Lomi, AlessandroOrganizations and NetworksHealthcare, Mutual Forbearence, Actor‐Based Stochastic ModelingSAT.PM2Organizations competing simultaneously across multiple markets, product lines, customer segments, or spatial locations are multipoint rivals. Almostregardless of the specific setting for the encounters, extant research reveals that multipoint rivals enjoy increased growth rates, experience improved survivalchances, are able to charge higher prices, and control more stable market shares. If competition across multiple markets is universally beneficial why don’t allorganizations increase their degree of multipoint contact with their rivals to share the benefits of mutual forbearance? This question shifts the focus ofattention from the consequences of multipoint competition to its antecedents. To examine this issue, in this paper we use data that we have collected onmultipoint contact between hospitals across twenty‐five major diagnostic categories during the period 2003‐2007. We estimate stochastic dynamic agentbasedmodels that specify the conditional probability of change in multipoint contact as a function of the presence of collaborative network ties, institutionaland organizational characteristics of the hospitals, and endogenous network mechanisms. In direct support of the mutual forbearance hypothesis, we find thatreciprocation and the existence of prior network ties make organizations more likely to enter market segments already occupied by rivals. We find, further,that multipoint contact is more likely to be established between organizations sharing the same rivals, i.e., between structurally equivalent organizations.Finally, we find that multipoint contact is characterized by significant self‐reproduction tendencies: high levels of multipoint competition lead to furtherincrease in multipoint contact. We take these results as evidence that access to the benefits that mutual forbearance potentially affords is controlled bynetwork‐based mechanisms of relational coordination between organizations.The Network Structure Of Cooperation In Voluntary DilemmasScholz, John T.; Ahn, T. K.Collaboration, coordination and cooperationDynamic Network Analysis, Experiments, Cooperation, Co‐evolution, Collaboration Network, Coordination GamesFRI.PM2Social capital theory argues that cooperators in the large class of dilemmas often appear in clusters, but is unclear about whether clustering enhancescooperation or cooperators seek each other to create clusters. We report voluntary exchange experiments in which subjects select their partners and playiterated prisoners dilemma games. We describe a cooperative quit‐for‐tat strategy that quits any relationship after a defection, consider the structuralimplications of this strategy, and show that this strategy is consistent with the experimental results. We argue that selection produces the observed clustering,but that this result is dependent on the limited population size and limited length of the experiment. When cooperators seek other cooperators, the structureof cooperation will depend on population size, characteristics of the search for new partners, and the time horizon for cooperators.