http://repub.eur.nl/res/concept/jel-C79/ Recent publications classified by JEL Code C79 en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/11107/ 2006-07-12T00:00:00Z In this paper we study the structure of the bilateral communication links within Online Consumer Communication Networks (OCCNs), such as virtual communities. Compared to the offline world, consumers in online networks are highly flexible to choose their communication partners and little is known about how this affects communication exchange structures. We analyze these structures by using a general approach from the game-theoretic literature of social and economic network formation where individuals trade off the cost of forming and maintaining links against the potential rewards of doing so, which results in a stable network structure. In our analysis, a combination of aspects common to OCCNs is incorporated that has not been investigated in this literature until now. First, the negative externality of communication specificity is included in the sense that the more direct connections an individual has to maintain with other individuals, the less she is able to specify her attention per link within her total time available. Therefore, the additive value per individual of her communications declines with an increasing number of links, and she also derives less additive value per individual from others with an increasing number of links. Second, a distinction is made between the social and informational value of communication, where informational communication value is assumed to be transferable via indirect links, whereas social communication value is not transferable. Analytical results are derived by using the concept of pairwise stability. A tendency towards fragmented pairwise stable structures - consisting of small, disjoint (star) components - is discovered, which can be attributed to the joint effect of the two aspects mentioned. We demonstrate that only some of the pairwise stable structures provide optimal welfare (total payoffs), and that the relative focus on informational versus social value of communication affects this welfare. Dellaert, B.G.C. Harmsen-van Hout, M.J.W. Herings, P.J.J. http://repub.eur.nl/res/pub/1937/ 2005-04-03T00:00:00Z We will firstly outline the rationale of a public good game and explain the distinction between a continuous public good game and a threshold public good game. As a vast majority of experimental research in social psychology on public good games has used threshold public good games, we will then outline the structure of a dilemma game with a provision point. Our point is that dilemma games with a provision point violate two important assumptions commonly held for public good games: a) there is always a conflict between the group’s interest and the individual’s interest; and b) an individual is always better off defecting. A threshold dilemma game is a dilemma with a coordination game embedded in it. Hence it provides focal point solutions and may as a consequence leave less room for other factors to affect behavior. Moreover, games with a provision point might yield different results than games without a provision point. We will argue that above that threshold dilemma games do not provide good models of many the public goods problems that are encountered in real life. We will propose that a public good game with a tilted S function provides a more appropriate model of real life dilemmas while fulfilling the defining properties of public good games. Abele, S.C. Stasser, G. http://repub.eur.nl/res/pub/6803/ 2002-07-10T00:00:00Z This paper studies network formation in settings where players are heterogeneous with respect to benefits as well as the costs of forming links. Our results demonstrate that centrality, center-sponsorship and short network diameter are robust features of equilibrium networks. We find that in a society with many groups, where it is cheaper to connect within groups as compared to across groups, strategic play by individuals leads to a network architecture in which there is a core group which is entirely internally connected while all the other groups are entirely externally linked and hence completely fragmented. Since internal/within group links are cheaper to form, this implies that individual incentives may generate a significant waste of valuable social resources. Galeotti, A. Goyal, S.