The Expressivity of Quantified Group Announcements

Group announcement logic (GAL) and coalition announcement logic (CAL) allow us to reason about whether it is possible for groups and coalitions of agents to achieve their desired epistemic goals through truthful public communication. The difference between groups and coalitions in such a context is that the latter make their announcements in the presence of possible adversarial counter-announcements. As epistemic goals may involve some agents remaining ignorant, counter-announcements may preclude coalitions from reaching their goals. We study the relative expressivity of GAL and CAL and provide some results involving their more well-known sibling APAL. We also discuss how the presence of memory alters the relationship between groups and coalition

How the Rules of Coalition Formation Affect Stability of International Environmental Agreements

This paper compares stability of international environmental agreements for six different rules of coalition formation under very general conditions (any type of heterogeneity between countries). The rules can be interpreted as different institutional settings in which treaty formations take place and/or different designs of agreements. We consider open and restricted open membership game as well as four exclusive membership games with different degrees of unanimity required to form coalitions. From a policy perspective, counterintuitively, it turns out that stability is higher under exclusive than under open membership and stability increases with the degree of unanimity. We discuss the policy implications of our result for future treaty-making.Non-cooperative game theory, Rules of coalition formation, Stability

Collectively Incentive Compatible Tax Systems

This paper assumes that individuals possess private information both about their abilities and about their valuation of a public good. Individuals can undertake collective actions on order to manipulate the tax system and the decision on public good provision. Consequently, an implementable scheme of taxation has to be collectively incentive compatible. If preferences are additively separable, then an implementable tax systems has the following properties: (i) tax payments do not depend on public goods preferences and (ii) there is no scope for a collective manipulation of public goods preferences. For a quasilinear economy, the optimal tax system is explicitly characterized.Optimal Taxation, Public Good Provision, Revelation of Preferences, Information Aggregation

Why Blu-ray vs. HD-DVD is not VHS vs. Betamax: The co-evolution of standard-setting consortia

Extensive research has been conducted on the economics of standards in the last three decades. To date, standard-setting studies emphasize a superior role of demand-side-driven technology diffusion; these contributions assume the evolution of a user-driven momentum and network externalities. We find that consumers wait for a dominant standard if they are unable to evaluate technological supremacy. Thus, supply-side driven activities necessarily need to address a lacking demand-side technology adoption. Our paper focuses on Blu-ray vs. HD-DVD as an illustrative case of consortia standard wars. One central role of consortia is to coordinate strategic behavior between heterogeneous agents, e.g. incumbents, complementors (content providers) and others, but also to form a coalition against other standard candidates. More precisely, we argue for signalizing activities through consortia events. We depict the essential role of consortia structures for the recently determined standard war between the High-Definition disc specifications Blu-ray and HD-DVD. Therefore, the paper suggests that unique supply-side dynamics from consortia structures, consortia announcements and exclusive backing decisions of firms determined the standard-setting process in the Blu-ray vs. HD-DVD standard war. This study is based on the following data: movie releases and sales numbers, membership affiliation for structural consortia analysis, and an in-depth event study. A detailed comparison of the technological specifications of both standard specifications supports our argument that there was no technological supremacy of one standard candidate from a consumer-oriented usecase perspective. We furthermore clarify that content providers (complementors) such as movie studios and movie rental services feature a gate-keeping position in the Blu-ray vs. HD-DVD standard war. In the case of Blu-ray, film studios decided the standard war because the availability of movie releases, but not technological supremacy, made the standard attractive to consumers. Finally, we find that there is a co-evolution of the consortia in terms of membership dynamics. Particularly, firm allegiance of heterogeneous agents plays a crucial role. --Blu-ray,HD-DVD,standard wars,co-evolution,consortia,event study

Strategic Voting in Multiparty Systems: A Group Experiment

The paper tests the theory of strategic voting for multiparty systems with proportional representation and coalition governments at the micro-level. The study focuses in particular on the question whether participation in repeated elections allows voters to learn from experience and enables them to optimize their decision behavior. An economic group experiment with decision scenarios of varying degrees of difficulty was used to test decision making at both the individual and group level. The results suggest that a majority of voters were able to pursue successful decision strategies and that the difficulty of the decision scenarios affected the voting performance of the participants as expected. However, a learning effect is not supported by the data.

Coalitional Approaches to Collusive Agreements in Oligopoly Games.

In this paper we review a number of coalitional solution concepts for the analysis of the stability of cartels and mergers under oligopoly. We show that, although so far the industrial organization and the cooperative game-theoretic literature have proceeded somehow independently on this topic, the two approaches are highly inter-connected. We first consider the basic problem of the stability of the whole industry association of firms under oligopoly and, for this purpose, we introduce the concept of core in games with externalities. We show that different assumptions on the behaviour as well as on the timing of the coalitions of firms yield very di¤erent results on the set of allocations which are core-stable. We then consider the stability of associations of firms organized in coalition structures different from the grand coalition. To this end, various coalition formation games recently introduced by the so called endogenous coalition formation literature are critically reviewed. Again, di¤erent assumptions concerning the timing and the behaviout of firms are shown to yield a wide range of different results.Cooperative Games, Coalitions, Mergers, Cartels, Core, Games with Externalities, Endogenous Coalition Formation.

Why blu-ray vs. HD-DVD ist not VHS vs. Betamax: the co-evolution of standard-setting consortia

Extensive research has been conducted on the economics of standards in the last three decades. To date, standard-setting studies emphasize a superior role of demand-side-driven technology diffusion; these contributions assume the evolution of a user-driven momentum and network externalities. We find that consumers wait for a dominant standard if they are unable to evaluate technological supremacy. Thus, supply-side-driven activities necessarily need to address an absence of demand-side technology adoption. Our paper focuses on Blu-ray vs. HD-DVD as an illustrative case of consortia standard wars. One central role of consortia is to coordinate strategic behavior between heterogeneous agents, e.g. incumbents, complementors (content providers) and others, but also to form a coalition against other standard candidates. More precisely, we argue that agents signal standard-setting war outcomes through consortia events. We depict the essential role of consortia structures for the recently determined standard war between the High-Definition disc specifications Blu-ray and HD-DVD. Therefore, the paper suggests that unique supply-side dynamics from consortia structures, consortia announcements and exclusive backing decisions of firms determined the standard-setting process in the Blu-ray vs. HD-DVD standard war. This study is based on the following data: movie releases and sales numbers, membership affiliation for structural consortia analysis, and an in-depth event study. A detailed comparison of the technological specifications of both standard specifications supports our argument that there was no technological supremacy of one standard candidate from a consumer-oriented usecase perspective. We furthermore clarify that content providers (complementors) such as movie studios and movie rental services feature a gate-keeping position in the Blu-ray vs. HD-DVD standard war. In the case of Blu-ray, film studios decided the standard war because the availability of movie releases, but not technological supremacy, made the standard attractive to consumers. Finally, we find that there is a co-evolution of the consortia in terms of membership dynamics. Particularly, firm allegiance of heterogeneous agents plays a crucial role. --Blu-ray,HD-DVD,standard wars,co-evolution,consortia,event study

Using Tuangou to reduce IP transit costs

A majority of ISPs (Internet Service Providers) support connectivity to the entire Internet by transiting their traffic via other providers. Although the transit prices per Mbps decline steadily, the overall transit costs of these ISPs remain high or even increase, due to the traffic growth. The discontent of the ISPs with the high transit costs has yielded notable innovations such as peering, content distribution networks, multicast, and peer-to-peer localization. While the above solutions tackle the problem by reducing the transit traffic, this paper explores a novel approach that reduces the transit costs without altering the traffic. In the proposed CIPT (Cooperative IP Transit), multiple ISPs cooperate to jointly purchase IP (Internet Protocol) transit in bulk. The aggregate transit costs decrease due to the economies-of-scale effect of typical subadditive pricing as well as burstable billing: not all ISPs transit their peak traffic during the same period. To distribute the aggregate savings among the CIPT partners, we propose Shapley-value sharing of the CIPT transit costs. Using public data about IP traffic of 264 ISPs and transit prices, we quantitatively evaluate CIPT and show that significant savings can be achieved, both in relative and absolute terms. We also discuss the organizational embodiment, relationship with transit providers, traffic confidentiality, and other aspects of CIPT