Why Share in Peer-to-Peer Networks

Prior theory and empirical work emphasize the enormous free-riding problem facing peer-to-peer (P2P) sharing networks. Nonetheless, many P2P networks thrive. We explore two possible explanations: private provision of public goods and generalized reciprocity. We investigate a particular form of private incentives to share content: redistributing traffic in the network to the advantage of the sharing peer. Our preliminary model suggests that this incentive is likely insufficient to motivate equilibrium content sharing in large networks. We then approach P2P networks as a graph-theoretic problem and derive sufficient conditions for sharing and free-riding to co-exist in the absence of direct sharing benefits or an explicit incentive mechanism.http://deepblue.lib.umich.edu/bitstream/2027.42/49504/1/NetEcon06-final.pd