Kandori. and R. Organization Science. and T. 2008 . Agres. Service ince ntives include giving priority to frequent contributors in download queues or allowing simultaneous downloads of multiple files. social-psychological forces. 1987. 2000. 2006. thus limiting direct reciprocity. Galit Shmueli. the peer-to-peer network provides special title called ??Value Users?? to frequent contributors. E. Motivation.2 and potential legal liabilities in sharing priv ileged. we can isolate social influence from individual variations. many peer-to-peer networks automati cally track individual c ontribution history and identify frequent contributors. S. individual interactions in peer-to-peer networks resemble one-shot games where Prisoner??s dilemma is prevalent. and use value Shah 2006. contributors who both contribute to and Louis vuitton uk from the peer-to-peer network H1a . Finally. We show that one action that could be very effective is to provide contributors with a mechanism to reward each other and to punish free riders. and Louis Vuitton Journal of Economic Perspectives 14 3 159?C181.D. 2001. 2003. Actions intended to benefit or harm a recipient is more likely to be reciprocated than the actions that produce accidental benefits or harms.. Brandt. Fehr and Gachter 2000b. Management Science 47 9 1203-1219. Chen. The second set identifies individuals?? incentive to enforce social norms by punishing free riders and rewarding contributors. This is consistent with the reputation mechanism that makes these contributors more concerned about the long-term sustainability of the network. MacKie-Mason. Our analysis provides empirical evidences to show that indirect reciprocity is an important f actor for contribution. network connection costs. Sigmund. D. For example.D. DeSanctis. extrinsic in centives include organizational rewards Bock et al. Nature 444 7120 718-723. 1968. Why should i sh are? Examining knowledge contribution in electronic networks of practice. Jeppesen. Hosanagar. .. These studies provide insights into why individuals differ in their contribution levels. The second set identifies individuals?? incentive to enforce social norms by punishing free riders and rewarding contributors. the summary statistics reveal that Louis Vuitton Outlet of all contributors use some form of reward and punishment mechanisms by providing better services to other contributors. Instead. Y. Incentives A number of experimental studies find that incentives could increase private contribution to public goods Falkinger et al. H. The ratio of free riders to contributors is 6. and M. The ratio of free riders to contributors is 6. Reciprocity is especially important in social dilemmas where private interests conflict with collective interests Rabin 1993 . A self-int erested responder is not expected to return anything to the proposer. The tragedy of the commons. The result reveals the social enforcement mechanism in a large social network. Second. competition. Zmud.-W. E. J. We therefore propose: H1a: Positive Indirect Reciprocity - a user??s probability of contribution in creases with the number of other contributors in a peer-to-peer network. governance and the viability of hybrid forms in open source software development. M. K. First. A. 1986a. DangNguyen. . Indirect re ciprocity. reciprocity Wasko and Faraj 2005. Third. the analysis above indicates that indirect reciprocity is an important dynamic social force in Louis Vuitton UK networks. All errors remain ours. Some simple economics of open source. 1993. th ey do not capture the dynamic nature of so cial networks. Contribution costs are largely fixed for an individual. Konana. We extend these studies by identifying the dynamic nature of indirect reciprocity in a large peer-to-peer network a nd uncovering the social mechanism that enforces the norm of contribution in the network.. then a decrease in on e individual??s contribu tion would affect her neighbors. and moreover. individuals?? contribution levels gradually decrease to the equilibrium level of zero contribution. B. American Economic Review 90 1 247-264. We describe data and measures afterward. but a person who fails to punish is in turn punished . As such. studies show that the effectiveness louis vuitton outlet such mechanisms is limited as individuals can easily change online identifications and contribution of negative feedbacks is often re taliated with negative feedbacks Novak and Sigmund 2005 . Replicating Online Yankee Auctions to Analyze Auctioneers' and Bidders' Strategies.. the technology allows her to punish all free ri ders by setting up her server to provide downloads only to other contributors or give download priorities to other contributors. MacKie-Mason. Our analysis indicates that indirect reciprocity could be a key motivating factor for contribut ion to peer-to-peer networks and has a significant influence on the social dynamics inside these networks. Our analysis has a number of limitations. Faraj.. Oxford University Press.330 users?? activities in louis vuitton outlet peer-to-peer network over 121 days.. 2003. For example. S. Journal of Economic Perspective 14 3 137-158. For example. The experi ment shows that individuals have inherent incentive to contribute to public goods. many peer-to-peer networks automati cally track individual c ontribution history and identify frequent contributors. Falk et al. Public goods: a survey of expe rimental research. Gribble. Information Systems Research 12 4 346-362. W hy share in peer-to-peer networks? Proceedings of the ACM EC 2006 workshop on the Economics of Networked Systems . Krishnan. 2000. 2008 . J. however. Espinosa. Slaughter. and organizational climate. Management Science 49 2 160-178.