Sequential pivotal mechanisms for public project problems

It is well-known that for several natural decision problems no budget balanced Groves mechanisms exist. This has motivated recent research on designing variants of feasible Groves mechanisms (termed as `redistribution of VCG (Vickrey-Clarke-Groves) payments') that generate reduced deficit. With this in mind, we study sequential mechanisms and consider optimal strategies that could reduce the deficit resulting under the simultaneous mechanism. We show that such strategies exist for the sequential pivotal mechanism of the well-known public project problem. We also exhibit an optimal strategy with the property that a maximal social welfare is generated when each player follows it. Finally, we show that these strategies can be achieved by an implementation in Nash equilibrium.Comment: 19 pages. The version without the appendix will appear in the Proc. 2nd International Symposium on Algorithmic Game Theory, 200

Ratification quotas in international agreements

This paper analyses the role of ratification quotas in multilateral agreements over emission reduction. The higher is the quota, the lower is the level of emissions in case the agreement comes into force, but the higher is also the risk of failure. In a setting with incomplete information, two country types and a binary contribution to the provision, I examine the differences between simultaneous and sequential ratification. When the benefits from emission of both types are smaller than the social costs, the outcome in the simultaneous case is essentially identical to the sequential case. The optimal quota is 100% and achieves the first best. With the high type's benefits exceeding the social costs, I find that the optimal quota is as small as possible, if ratification is simultaneous. In the sequential ratification case, I cannot determine the optimal quota. However, I find that the aggregate expected surplus decreases with respect to the simultaneous case

A System for Distributed Mechanisms: Design, Implementation and Applications

We describe here a structured system for distributed mechanism design appropriate for both Intranet and Internet applications. In our approach the players dynamically form a network in which they know neither their neighbours nor the size of the network and interact to jointly take decisions. The only assumption concerning the underlying communication layer is that for each pair of processes there is a path of neighbours connecting them. This allows us to deal with arbitrary network topologies. We also discuss the implementation of this system which consists of a sequence of layers. The lower layers deal with the operations that implement the basic primitives of distributed computing, namely low level communication and distributed termination, while the upper layers use these primitives to implement high level communication among players, including broadcasting and multicasting, and distributed decision making. This yields a highly flexible distributed system whose specific applications are realized as instances of its top layer. This design is implemented in Java. The system supports at various levels fault-tolerance and includes a provision for distributed policing the purpose of which is to exclude `dishonest' players. Also, it can be used for repeated creation of dynamically formed networks of players interested in a joint decision making implemented by means of a tax-based mechanism. We illustrate its flexibility by discussing a number of implemented examples.Comment: 36 pages; revised and expanded versio

On the Number of alpha-Pivotal Players

We show that bounds like those of Al-Najjar and Smorodinsky (J. Econ. Theory, 2000) as well as of Gradwohl et al. (Math. Oper. Res., 2009) on the number of alpha-pivotal agents can be obtained by decomposition of variance. All these bounds have a similar asymptotic behaviour, up to constant factors. Our bound is weaker than that of Al-Najjar and Smorodinsky, but we require only pairwise independent—rather than independent—types. Our result strengthens the bound of Gradwohl et al.alpha-pivotal agent, influence, direct mechanism, decomposition of variance

Voting in Corporate Boards with Heterogeneous Preferences

We analyze the voting behavior of a board of directors that has to approve (or reject) an investment proposal with uncertain return. We consider three types of directors: insiders, who are biased toward acceptance of the project, independent outsiders who want to maximize the firm's profit and independent outsiders who care about their reputation. We show that the presence of members with heterogeneous preferences can be beneficial and that the partisan behavior of insiders can be used as a sort of coordinating device by uninformed outsiders. Provided that the size of the board is optimal, there is no gain from increasing the number of outsiders above the strict majority despite the fact that each outsider is informed with positive probability. Substituting profit-maximizing directors with directors concerned about their reputation is not an obstacle to profit maximization provided that an appropriate sequential voting protocol is followed. We also show that a proper board composition makes communication between directors irrelevant in the sense that the same outcome is obtained with and without communication. Finally, as information is costly, our model provides some suggestions on the optimal size of boards.Board of directors, Voting, Corporate Governance

Ratification quotas in international agreements

This paper analyses the role of ratification quotas in multilateral agreements over emission reduction. The higher is the quota, the lower is the level of emissions in case the agreement comes into force, but the higher is also the risk of failure. In a setting with incomplete information, two country types and a binary contribution to the provision, I examine the differences between simultaneous and sequential ratification. When the benefits from emission of both types are smaller than the social costs, the outcome in the simultaneous case is essentially identical to the sequential case. The optimal quota is 100% and achieves the first best. With the high type's benefits exceeding the social costs, I find that the optimal quota is as small as possible, if ratification is simultaneous. In the sequential ratification case, I cannot determine the optimal quota. However, I find that the aggregate expected surplus decreases with respect to the simultaneous case.public goods; international bargaining; ratfication; emission games

Is a Growing Middle Class Good for the Poor? Social Policy in a Time of Globalization

We examine the effect of the rise and evolution of the middle class on extreme poverty, using the World Bank's international poverty line of $1.90 per person per day in 2011 purchasing power parity (PPP)- adjusted terms. Like the definition of poverty, the definition of the middle class used here is also set in absolute terms, comprising households where per capita income or consumption lies between$11 and $110 per person per day in 2011 PPP terms—referred to as a "global," as opposed to national, definition of the middle class (Kharas, 2017). We argue that middle-class expansion initially is pro-poor given the incentives of the emerging middle class and the working poor to cooperate on matters of social policy. As citizens join the ranks of the middle class, they lobby for programs that provide them income stability and protections against shocks (social insurance). By allying with the working poor who seek social assistance (income transfers), middle-class constituents increase their bargaining power relative to elites who seek labor flexibility and lower taxes in a competitive global economy. Over time, however, as the middle class prospers and acquires greater political influence, the balance of programs shifts increasingly toward social insurance and away from social assistance. In this way, the middle class begins to capture an increasing proportion of the benefits of social spending, leaving less for welfare services targeted exclusively at the poorest. One implication of this is that the emerging middle class has never been truly progressive, because progressivity ultimately comes at its own expense

Overcoming Free Riding in Multi-Party Computations

This paper addresses the question of multi party computation in a model with asymmetric information. Each agent has a private value (secret), but in contrast to standard models, the agent incurs a cost when retrieving the secret. There is a social choice function the agents would like to compute and implement. All agents would like to perform a joint computation, which input is their vector of secrets. However, agents would like to free-ride on others contribution. A mechanism which elicits players secrets and performs the desired computation defines a game. A mechanism is `appropriate if it (weakly) implements the social choice function for all secret vectors. namely, if there exists an equilibrium in which it is able to elicit (sufficiently many) agents secrets and perform the computation, for all possible secret vectors. We show that `appropriate mechanisms approach agents sequentially and that they have low communication complexity