Bargaining over a climate deal: is it worse to wait and see?

Assuming that a North-South transfer is the key to climate cooperation, we ask when and how much the North should o¤er to the South in return for a commitment to reduce deforestation and forest degradation. In light of the risk of irreversible damage over time, we examine a negotiation with a deadline. We assess the conditions for an agreement to be immediate or delayed, and discuss situations likely to result in negotiation failure. Despite the risk of irreversible damage over time, we show that cooperation is likely to be delayed and characterize situations where North and South fail to agree within the deadline. Although Pareto-improving, cooperation may collapse because of inefficiencies related to incomplete information. We show that in negotiations with a deadline, uncertainty about the benefi…ts deriving from cooperation and the irreversibility of the damage that will be caused if cooperation is delayed, are the two key components affecting choice.

Learning to trust strangers: an evolutionary perspective

What if living in a relatively trustworthy society was sufficient to blindly trust strangers? In this paper we interpret generalized trust as a learning process and analyse the trust game paradox in light of the replicator dynamics. Given that trust inevitably implies doubts about others, we assume incomplete information and study the dynamics of trust in buyer-supplier purchase transactions. Considering a world made of “good” and “bad” suppliers, we show that the trust game admits a unique evolutionarily stable strategy: buyers may trust strangers if, on the whole, it is not too risky to do so. Examining the situation where some players may play, either as trustor or as trustee, we show that this result is robust.

The Making of International Environmental Agreements

We examine in this paper the formation and the stability of international environmental agreements when cooperation means to commit to a minimum abatement level. Each country decides whether to ratify the agreement and this latter enters into force only if it is ratified by a number of countries at least equal to some ratification threshold. We analyze the role played by ratification threshold rules and provide conditions for international environmental agreements to enter into force. We show that a large typology of agreements can enter into force among the one constituted by the grand coalition.International Environmental Agreement,

Influence processes in climate change negotiations: Modelling the rounds

I present in this paper an integrated framework for structuring and evaluating dynamic and sequential climate change decision making in the international arena taking into account influence processes occuring during negotiation rounds. The analysis integrates imitation, persuasion and dissuasion behaviors. The main innovation brought in the approach is the presentation of a stochastic model framework derived from thermodynamics. The so-called master equation is introduced in order to better understand strategic switch and influence games exerted. The model is illustrated toward a simulation of climate change conferences decision making processes. Characteristics of regions behaviors are derived from the simulations. In particular the bargain behaviors allowing for the emergence of an agreement are presented

How to play the games? Nash versus Berge behavior rules

Social interactions regularly lead to mutually beneficial transactions that are sometimes puzzling. The prisoner’s dilemma and the chicken and trust games prove to be less perplexing than Nash equilibrium predicts. Moral preferences seem to complement self-oriented motivations and their relative predominance in games is found to vary according to the individuals, their environment, and the game. This paper examines the appropriateness of Berge equilibrium to study several 2×2 game situations, notably cooperative games where mutual support yields socially better outcomes. We consider the Berge behavior rule complementarily to Nash: individuals play one behavior rule or another, depending on the game situation. We then define non-cooperative Berge equilibrium, discuss what it means to play in this fashion, and argue why individuals may choose to do so. Finally, we discuss the relationship between Nash and Berge notions and analyze the rationale of individuals playing in a situational perspective.

What trends exist in regional housing market data?

While analysts have devoted much attention to housing market performance at the national, state, and even local level, far less attention has been paid to housing markets at the regional level. We investigate how regional vacancies, population, net migration, and other demographic variables have affected regional housing activity over several recent business cycles.Business cycles ; Housing

An evolutionary approach to the climate change negotiation game

We describe in this paper an evolutionary game theoretic model aiming at representing the climate change negotiation. The model is used to examine the outcome of climate change negotiations in a framework which seeks to closely represent negotiation patterns. Evolutionary setting allows us to consider a decision making structure characterised by agents with bounded knowledge practising mimics and learning from past events and strategies. We show on that framework that a third significant alternative to the binary coordination-defection strategies needs to be considered: a unilateral commitment as precautionary strategy. As a means to widen cooperation, we examine the influence of linking environmental and trade policies via the implementation of a trade penalty on non cooperative behaviours

Une approche évolutionnaire des négociations internationales en présence de problèmes environnementaux globaux

Le présent papier s'articule autour des problèmes environnementaux globaux, et se propose de lier les négociations internationales au comportement de précaution. Cela nous conduit à montrer que le comportement de précaution peut aussi bien survenir à la suite d'un échec des négociations qu'à la conclusion d'un accord. Dans le premier cas, ce comportement a moins d'impact que la coopération de tous, mais tend tout de même à réduire la portée de la défection. Dans le second cas, si un accord est signé entre un petit nombre de pays, le comportement de précaution constitue un moyen d'élargir la portée de la coopération sans déstabiliser la coalition coopérante. Nous montrons, enfin, que l'adoption de sanctions à l’encontre des pays non-coopérants ne garantit pas pour autant l'émergence d'un large mouvement de coopération.Problèmes environnementaux globaux, Coalition, Engagement unilatéral, Stratégie évolutionnaire

Density of states in a superconductor carrying a supercurrent

We have measured the tunneling density of states (DOS) in a superconductor carrying a supercurrent or exposed to an external magnetic field. The pair correlations are weakened by the supercurrent, leading to a modification of the DOS and to a reduction of the gap. As predicted by the theory of superconductivity in diffusive metals, we find that this effect is similar to that of an external magnetic field.Comment: To be published in Physical Review Letter