Peer-to-Peer Computing

Chapter 5

Incentives

5.1 Introduction

The highly flex ible features of P2P computing such as a dynamic popula-

tion (users come and go asynchronously at will), dynamic topolo gies (it is im-

practical, if not impossible, to enforce a fixed communication structure), and

anonymity, come at a significant cost—autonomy, by its very nature, is not

always in harmo ny with tight cooperation. Consequently, inefficient or lack of

cooperation could lead to undesirable e ffects in P2P computing. Among them

the most critical one is “fre e-riding” [Feldman and Chuang, 2005,Ramaswamy

and Liu, 2003] behavior. Loosely speaking, free-riding oc curs when some users

do not follow ...