%0 Journal Article %T Dynamics of illegal participation in peer-to-peer networks—why do people illegally share media files? %A Becker, Jan U. %A Clement, Michel %D 2006 %J Journal of Media Economics %@ 0899-7764 %N 1 %V 19 %P 7–32 %! Becker, Clement 2006 – Dynamics of illegal participation %R 10.1207/s15327736me1901_2 %X The rise of peer-to-peer networks starting with Napster in 1999 and later KaZaA and eMule had a substantial impact on the online distribution of media content. Millions of users at any given point of time illegally offer copyright protected files and internalize the cost of their behavior. Whereas it is easy to explain why users download files, it remains an open question as to why they provide data, because it is not necessary to get access to files. This article addresses the issue of why users take the risk and illegally provide files. In a theoretical analysis relying on game theoretical assumptions, this article shows in a dynamic context that users actually do follow a rational strategy by providing files. This article underlines the theoretical assumptions with two empirical studies. The first study researches the individual motives for file sharing by using a structural equation model. Reciprocity is one of the key drivers to offer files. The second study segments users based on their motives into three groups using mixture regressions. The results imply that there is a large segment free riding on their peers. The research also finds a heavy sharer segment that is motivated to share, even at the risk of being sued. This article follows a dynamic perspective in the user's willingness to share that allows researchers to provide implications on the stability of the networks in the long term, because the users' behavior may lead to the collapse of illegal networks. %~ EndNote Tagged Import Format