1,721,145 research outputs found
Majority Rules and Coalition Stability
No full textWe consider a class of symmetric games with externalities across coalitions and show that, under certain regularity conditions, restricting the deviating power to majority guarantees the existence of core-stable allocations. We also show that if majorities canextract resources from minorities, stability requires a supermajority rule, whose thresholdis increasing in the extraction power
The Kinked Demand Model and the Stability of Cooperation
No full textThis paper focusses on a particular behaviour for firms competing in imperfect competitive markets firstly theorized in the late 30s by a number of well known economists (Robinson (1933), Sweezy (1939)). This is the well known model of kinked demand curve, basically predicting an asymmetric behaviour of every firm in response to a price change: each firm expects its rivals to be more reactive in matching its price cuts than its price increases. Although this theory has been often criticized as not theoretically grounded, we show that this is not the case. In particular, in a symmetric and monotone market, we prove that, if every firm accepts a simple kinked-demand norm of behaviour (KD), the perfectly collusive outcome (monopoly pricing) constitutes an equilibrium. We show that this result is rather robust and can be extended to all symmetric strategic form games in which players are allowed to deviate either individually or in a coordinated manner as coalitions of players: a KD norm of behaviour always makes the efficient outcome (the one maximizing the sum of all players' utility) stable. Also, we show that a slightly stronger norm of behaviour (implicitly implying a norm of reciprocity) makes the efficient outcome the only stable outcome of the game. Finally, the KD norm of behaviour can also be considered rational whenever players' actions are strategic complements in the sense of Bulow et al. (1982)
Coalition Formation in Games without Synergies
No full textThis paper establishes sufficient conditions for the existence of a stable coalition structure in the “coalition unanimity” game of coalition formation, first defined by Hart and Kurz (1983) and more recently studied by Yi (1997, 2003). Our conditions are defined on the strategic form game used to derive the payoffs of the game of coalition formation. We show that if no synergies are generated by the formation of coalitions, a stable coalition structure always exists provided that players are symmetric and either the game exhibits strategic complementarity or, if strategies are substitutes, the best reply functions are contractions
Coalitional Approaches to Collusive Agreements in Oligopoly
Full text linkIn this paper we review a number of coalitional solution concepts for the analysis of cartel and merger stability in 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 show that different assumptions on the behaviour and on the timing of the coalitions of firms yield very different results on the associations of firms which are stable. We conclude by reviewing some recent extensions of the coalitional analysis to oligopolistic markets with heterogeneous firms and incomplete information. © 2014 The University of Manchester and John Wiley & Sons Ltd
Sequential Play and Cartel Stability in Cournot Oligopoly
No full textWe reconsider the problem of cartel stability in a linear symmetric Cournot oligopoly by assuming that every coalition of firms defecting from a cartel can choose its quantity before the remaining firms. We show that differently from [5] the only profitable cartel includes all firms in the industry. This result is shown to be robust to nonlinearity of the profit function, provided that the inverse demand function is not too log-concave
Coalition Formation in Games without Synergies
Full text linkThis paper establishes sufficient conditions for the existence of a stable coalition structure in the ”coalition unanimity” game of coalition formation, first defined by Hart and Kurz (1983) and more recently studied by Yi (1997, 2000). Our conditions are defined on the strategic form game used to derive the payoffs the game of coalition formation. We show that if no synergies are generated by the formation of coalitions, a stable coalition structure always exists provided that players are symmetric and either the game exhibits strategic complementarity or, if strategies are substitutes, the best reply functions are contractions. We illustrate the role of synergies in a Cournot oligopoly example with cost reducing R&D.Coalition formation, Synergies, Strong Nash equilibrium
Kinked Norms of Behaviour and Cooperation
Full text linkThis paper revisits a particular norm of behaviour underlying the well known model of kinked demand. We show that under some standard regularity conditions this norm of behaviour sustains the efficient outcome in all symmetric games
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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