Network Structure in a Link-formation Game: An Experimental Study

Network formation is frequently modeled using link-formation games and typically present a multiplicity of Nash equilibria. Cooperative refinements - such as strong or coalitional proof Nash equilibria - have been the standard tool used for equilibrium selection in these games. Non-cooperative refinements derived from the theory of global games have shown also that, for a class of payoff functions, multiplicity of equilibria disappears when the game is perturbed by introducing small amounts of incomplete information. We conducted a laboratory study evaluating the predictive power of each of these refinements in an illustrative link-formation game. Compared with cooperative game solutions, the global game approach did significantly better at predicting the strategies played by individuals in the experiment.Networks, global games, cooperative games, equilibrium selection, experimental economics

Auctions with Resale Market and Asymmetric Information

In this paper we study the role of resale opportunities in secondary markets over the bidding process in first and second price auctions. This trade opportunity arises owing to the presence of two factors. On the one hand, after receiving the object, the winner obtains new information about the object’s value and on the other hand, the winner may suffer a liquidity shock that force him to sell the object regardless of his valuation. The buyer in the secondary market, however, does not know if the good is being sold because the new information reveals bad news regarding the object’s valuation, or because a liquidity shock affected the seller. Our results show that revenue equivalence still holds, and bids are usually lower than those observed in the absence of liquidity shocks.Auctions, resale market, adverse selection

The Role of Social Networks on Regulation in the Telecommunication Industry

This paper studies the welfare implications of equilibrium behavior in a market characterized by competition between two interconnected telecommunication firms, subject to constraints: the customers belong to a social network. It also shows that social networks matter because equilibrium prices and welfare critically depend on how people are socially related. Next, the model is used to study effectiveness of alternative regulatory schemes. The standard regulated environement, in which the authority defines interconnection ac cess charges as being equal to marginal costs and final prices are left to the market, is considered as a benchmark. Then, we focus on the performance of two different regulatory interventions. First, access prices are set below marginal costs to foster competition. Second, switching costs are reduced to intensify competition. The results show that the second strategy is more efective to obtain equilibrium prices closer to Ramsey's level.Access charges, social networks, random regular graphs

Giovanni Paolo II sulla scena del mondo. Magistero sociale, dialogo e diplomazia. [Reseña]

Reseña de Ugo COLOMBO SACCO DI ALBIANO, Giovanni Paolo II sulla scena del mondo. Magistero sociale, dialogo e diplomazia, Paoline («Saggistica Paoline», 21), Milano 2004, 256 pp., 14 x 21, ISBN 88- 315-2601-4

Religion and Civil Society. Rethinking Public Religion in the Contemporary World, Ashgate. [Reseña]

Reseña de David HERBERT, Religion and Civil Society. Rethinking Public Religion in the Contemporary World, Ashgate, Aldershot 2003, X + 322 pp., 16 x 23, ISBN 0-7546-1339-9

Historia de las ideas contemporáneas. Una lectura del proceso de secularización. [Reseña]

Reseña de Mariano FAZIO, Historia de las ideas contemporáneas. Una lectura del proceso de secularización, Rialp, Madrid 2006, 432 pp., 16 X 24, ISBN 84-321-3613-1