Group Bargaining and Conflict

We consider a situation where groups negotiate over the allocation of a surplus (which is used to fund group specific goods). Each group is composed of agents who have differing valuations for public goods. Members choose a representative to take decisions on their behalf. Specifically, representatives can decide to enter either a (cooperative) negotiation protocol or a conflict to appropriate the surplus. In the cooperative negotiations, disagreement corresponds to a pro rata allocation (as a function of the size of the groups). We analyse the conditions (on the internal composition of the groups) under which conflict will be preferred to negotiated agreements (and vice versa), and we derive welfare implications. Finally, we provide results of comparative statics that highlight the influence of changes in the internal composition of groups and in their relative size on the profitability of negotiated agreements.Bargaining, Conflict, Agency Problem

Consistent Conjectures in a Dynamic Model of Non-renewable Resource Management

We consider a dynamic model of non-renewable resource extraction under the assumption that players do not know their opponents' utility functions.[...]

On the (In-)Efficiency of Unanimity in Multilateral Bargaining with Endogenous Recognition

In this paper, we study the (symmetric) equilibria of a model of multilateral bar- gaining where players are heterogeneous regarding their time preferences, and make costly efforts at the beginning of the process in order to inuence their probabilities of being the proposer for all stages of the negotiation process. We analyse whether the optimality of the unanimity rule (as the voting rule minimizing the social cost resulting from the agents' willingness to buy inuence) characterised in Yildirim (2007) extends to the present situation. In the case of weakly heterogeneous agents, we show that k-majority rules may actually become strictly optimal. Then we provide numerical ex- amples that suggest that there are situations where each type of voting rule (unanimity and strict k-majority) may be socially optimal.

Voting Rules in Bargaining with Costly Persistent Recognition

In this paper, we consider a model of multilateral bargaining where homogeneous agents may exert e¤ort before negotiations in order to inuence their chances to become the proposer. E¤ort levels have a permanent effect on the recognition process (persistent recognition). We prove two main results. First, all voting rules are equivalent (that is, they yield the same social cost) when recognition becomes persistent. Secondly, an equilibrium may fail to exist, because players may have more incentives to reduce their e¤ort level (in order to be included in winning coalitions) than to increase it (in order to increase their proposal power). Both results di¤er greatly from the case where recognition is transitory: Yildirim (2007) shows that una- nimity is the unique strictly optimal rule, and that an equilibrium always exists (under mild assumptions) in such a setting. Moreover, our second conclusion is quite di¤erent from the one obtained in most of the existing literature on bargaining (which assumes an exogenous recognition process), where it is generally considered that it is always in an agents best interest to have a proposal power as high as possible.

Pricing in networks

This paper studies optimal pricing in networks in the presence of local consumption or price externalities. It analyzes the relation between prices and nodal centrality measures. Using an asymptotic approach, it shows that the ranking of optimal prices and strategies can be reduced to the lexicographic ranking of a specific vector of nodal characteristics. In particular, this result shows that with positive consumption externalities, prices are higher at nodes with higher degree, and with relative price externalities, prices are higher at nodes which have more neighbors of smaller degree.Social Networks, Network Externalities, Oligopolies

Smooth Multibidding Mechanisms

We propose a smooth multibidding mechanism for environments where a group of agents have to choose one out of several projects. Our proposal is related to the multibidding mechanism (Pérez-Castrillo and Wettstein, 2002) but it is “smoother” in the sense that small variations in an agent’s bids do not lead to dramatic changes in the probability of selecting a project. This mechanism is shown to possess several interesting properties. First, the equilibrium outcome is unique. Second, it ensures an equal sharing of the surplus that it induces. Finally, it enables reaching an outcome as close to efficiency as is desired.mechanism design, NIMBY

Ordinal Games

We study strategic games where players' preferences are weak orders which need not admit utility representations. First of all, we ex- tend Voorneveld's concept of best-response potential from cardinal to ordi- nal games and derive the analogue of his characterization result: An ordi- nal game is a best-response potential game if and only if it does not have a best-response cycle. Further, Milgrom and Shannon's concept of quasi- supermodularity is extended from cardinal games to ordinal games. We ¯nd that under certain compactness and semicontinuity assumptions, the ordinal Nash equilibria of a quasi-supermodular game form a nonempty complete lattice. Finally, we extend several set-valued solution concepts from cardinal to ordinal games in our sense.Ordinal Games, Potential Games, Quasi-Supermodularity, Rationalizable Sets, Sets Closed under Behavior Correspondences

Pricing in networks

This paper studies optimal pricing in networks in the presence of local consumption or price externalities. It analyzes the relation between prices and nodal centrality measures. Using an asymptotic approach, it shows that the ranking of optimal prices and strategies can be reduced to the lexicographic ranking of a specific vector of nodal characteristics. In particular, this result shows that with positive consumption externalities, prices are higher at nodes with higher degree, and with relative price externalities, prices are higher at nodes which have more neighbors of smaller degree.Cet article analyse la fixation des prix dans un réseau en présence d'externalités de prix ou de consommation. Nous étudions la relation entre les prix et des mesures de centralité des points du réseau. En utilisant une approche asymptotique, nous montrons que l'ordre des prix et des stratégies optimales peut être approximé par un ordre lexicographique sur des caractéristiques nodales du réseau. Nous montrons que quand les agents font face à des externalités de consommation positives, les prix sont plus élevés dans les points du réseau au degré plus élevé. Quand les agents font face à des externalités relatives de prix, les prix sont plus élevés aux points du réseau qui ont le plus de voisins à faible degré

Smooth multibidding mechanisms

We propose a smooth multibidding mechanism for environments where a group of agents have to choose one out of several projects (possibly with the help of a social planner). Our proposal is related to the multibidding mechanism (Pérez-Castrillo and Wettstein, 2002) but it is "smoother" in the sense that small variations in an agent's bids do not lead to dramatic changes in the probability of selecting a project. This mechanism is shown to possess several interesting properties. Unlike in the study by Pérez Castrillo and Wettstein (2002), the equilibrium outcome is unique. Second, it ensures an equal sharing of the surplus that it induces. Finally, it enables reaching an outcome as close to effciency as is desired