Delay,multiplicity, and non-existence of equilibrium in unanimity bargaining games

We consider a class of perfect information bargaining games with unanimity acceptance rule. The proposer and the order of responding players are determined by the state that evolves stochastically over time. The probability distribution of the state in the next period is determined jointly by the current state and the identity of the player who rejected the current proposal. This protocol encompasses a vast number of special cases studied in the literature. We show that subgame perfect equilibria in pure stationary strategies need not exist. When such equilibria do exist, they may exhibit delay. Limit equilibria as the players become infinitely patient need not be unique.     

The method of leader's overthrow in networks based on Shapley value

Quantitative methods for leaders' detection and overthrow are useful tools for decision-making in many real-life social networks. In the given research, we present algorithms that detect and overthrow the most influential node to the weaker leadership positions following the greedy method in terms of structural modifications. We employ the concept of Shapley value from the area of cooperative game theory to measure a node's leadership and to develop the leader's overthrow algorithms. Specifically, we introduce a quantitative approach to analyze prospective structural modifications in social networks to make the initially identified network leader less influential. The resulting mechanism is based on the symbiosis of game-theoretic and algorithmic concepts. It presents a useful tool for the technical analysis of the primary structural data in the initial steps of multifaceted quantitative network analysis where the raw data (i.e., linkages) is frequently the only knowledge about interrelations in social networks.     

Revealed preferences of individual players in sequential games

This paper studies rational choice behavior of a player in sequential games of perfect and complete information without an assumption that the other players who join the same games are rational. The model of individually rational choice is defined through a decomposition of the behavioral norm assumed in the subgame perfect equilibria, and we propose a set of axioms on collective choice behavior that characterize the individual rationality obtained as such. As the choice of subgame perfect equilibrium paths is a special case where all players involved in the choice environment are each individually rational, the paper offers testable characterizations of both individual rationality and collective rationality in sequential games.     

合作博弈Shapley解的改进

合作博弈的Shapley解在利益分配过程中没有考虑到成员承担的风险等各种影响因素,从而导致分配的不合理。关于Shapley解的改进问题,先对以往的研究成果作了一个综述,然后提出了一种新的考虑更全面的分配策略。     

On axiomatizations of the Shapley value for assignment games

We consider the problem of axiomatizing the Shapley value on the class of assignment games. It turns out that several axiomatizations of the Shapley value on the class of all TU-games do not characterize this solution on the class of assignment games. However, when considering an assignment game as a (communication) graph game where the game is simply the assignment game and the graph is a corresponding bipartite graph where buyers (sellers) are connected with sellers (buyers) only, we show that Myerson’s component efficiency and fairness axioms do characterize the Shapley value on the class of assignment games. Moreover, these two axioms have a natural interpretation for assignment games. Component efficiency yields submarket efficiency stating that the sum of the payoffs of all players in a submarket equals the worth of that submarket, where a submarket is a set of buyers and sellers such that all buyers in this set have zero valuation for the goods offered by the sellers outside the set, and all buyers outside the set have zero valuations for the goods offered by sellers inside the set. Fairness of the graph game solution boils down to valuation fairness stating that only changing the valuation of one particular buyer for the good offered by a particular seller changes the payoffs of this buyer and seller by the same amount.     

Odd man out: the proposal-making model

The proposal-making model is applied to the class of three-player/three-cake problems. The set of subgame perfect equilibria (SPEs) and the limit set of SPE payoffs as the risk of breakdown vanishes is characterized. The necessary and sufficient condition for uniqueness is derived. The results for the alternating offer model play an important role. The model always admits one stationary SPE and this equilibrium is related to a multilateral Nash solution. The stationary SPE is the coalition-proof SPE and the limit result differs from the result known for the model without risk of breakdown.     

Simple collective equilibria in stopping games

At each moment in time, an alternative from a finite set is selected by a stochastic process. Players observe the selected alternative and sequentially cast a yes or a no vote. If the set of players casting a yes vote is decisive for the selected alternative, it is accepted and the game ends. Otherwise the next period begins. We refer to this class of problems as stopping games. Collective choice games, quitting games, and coalition formation games are particular examples. When the core of a stopping game is non-empty, a subgame perfect equilibrium in pure stationary strategies is shown to exist. But in general, even subgame perfect equilibria in mixed stationary strategies may not exist. We show that aggregate voting behavior can be summarized by a collective strategy. We insist on pure strategies, allow for simple forms of punishment, and provide a constructive proof to show that so-called two-step simple collective equilibria always exist. This implies the existence of a pure strategy subgame perfect equilibrium. We apply our approach to the case with three alternatives exhibiting a Condorcet cycle and to a model of redistributive politics.     

Auctions with resale and bargaining power

We show that when the weak bidder’s bargaining power in the resale market is weakened, the auctioneer’s revenue from the first-price auction with resale is lower. Using the idea of Coase Theorem, we show that when the resale market is a sequential bargaining model with no commitment, the auctioneer’s revenue is substantially reduced, and the ranking is the opposite of Hafalir and Krishna (2009). We establish a version of the Coase Theorem in the context of the auctions with resale. When Coase Theorem holds, we show that the revenue of the auction with resale is lower than the revenue of the same auction without resale. We also provide the existence and uniqueness of equilibrium for our model of auctions with resale.     

Null players,solidarity, and the egalitarian Shapley values

The Shapley value probably is the most eminent single-point solution concept for TU-games. In its standard characterization, the null player property indicates the absence of solidarity among the players. First, we replace the null player property by a new axiom that guarantees null players non-negative payoffs whenever the grand coalition’s worth is non-negative. Second, the equal treatment property is strengthened into desirability. This way, we obtain a new characterization of the class of egalitarian Shapley values, i.e., of convex combinations of the Shapley value and the equal division solution. Within this characterization, additivity and desirability can be replaced by strong differential monotonicity, which translates higher productivity differentials into higher payoff differentials.     

How to share when context matters: The Möbius value as a generalized solution for cooperative games

All quasivalues rest on a set of three basic axioms (efficiency, null player, and additivity), which are augmented with positivity for random order values, and with positivity and partnership for weighted values. We introduce the concept of Möbius value associated with a sharing system and show that this value is characterized by the above three axioms. We then establish that (i) a Möbius value is a random order value if and only if the sharing system is stochastically rationalizable and (ii) a Möbius value is a weighted value if and only if the sharing system satisfies the Luce choice axiom.     

Strategic militancy and the probability of strikes in union-firm bargaining

The paper provides a model that explains the probability of strikes by the union's use of militancy as a strategic tool in bargaining. Militants are useful because they provide a credible threat, hence enhancing the union's bargaining position. Using a multi-stage bargaining game, we show that, in general, militants will be used by the union as a strategic tool. The strategic benefit of militancy is reflected by the fact that the wage and employment level will be higher in a union that uses militants, compared to a union that does not. We use the model to show that the level of militancy and the probability of a strike decrease with the union's power. This suggests that policies that increase the strength of the union will have, at least, a partial positive effect on social welfare. We also show that the model can be viewed as providing an equilibrium of a repeated game, an interpretation that can explain the probability of strikes even in the absence of militants.     

The influence of seller learning and time constraints on sequential bargaining in an artificial perishable goods market

This paper investigates the formation of prices in a perishable goods market where agents bargain repeatedly through pair-wise interactions. After extensive field observations, we chose to focus on two aspects that seem important to actors of this market: the passage of time and update in judgement when gathering information. The main feature of the market is that a seller bargaining with a buyer has incomplete information about buyer's willingness to pay and is not sure how her trading partner will evaluate an offer or compare it with other options. On the other hand, buyers have limited time to look for goods and cannot meet all possible sellers before making a decision. Hence agents cannot calculate the best price to offer but receive information through limited interactions, and use this information to choose their actions.An agent-based model was built to represent a framework that mimics the observed market institution and where agent's possible behaviors and learning was made as consistent as possible with gathered data. Simulations were run, first for sensitivity analysis concerning main parameters, then to test the dependance of agents’ learning to (a) the time buyers can spend on the market and (b) the frequency of update in learning by sellers. To validate the model, features produced by the simulated market are compared to the stylized facts gathered for negotiation about four goods. We reproduce the main features of the data on the dynamics of offers, transaction prices and agents’ behavior during the bargaining phases.     

The effects of bargaining power on trade credit in a supply network

We develop a multi-tier supply network model, rooted in social network theory, to evaluate the effect of bargaining power on trade credit and to track the effect of buyers' trade credit on suppliers' trade credit. We apply social network analysis to measure companies' bargaining power in the supply network of Hennes & Mauritz AB (H&M, the Swedish clothing retailer). The results show that the buyer's bargaining power significantly affects the choice of trade credit, and that the supplier's “upstreamness” is significantly associated with its trade credit. We find limited evidence to support the notion of a financial bullwhip effect, a result that merits further research, since this study is limited to the network of one company up to its fourth tier of suppliers in one financial year. Our results can be applied by companies seeking to control their cash flow and, therefore, the financial pressure within their supply network. This study contributes to the literature by bringing social network measures into the buyer–supplier financial flow, as well as offering one of the first empirical examinations of the propagation of financial pressure in a multi-tier supply network.     

Value capture in hierarchically organized value chains

We study how the structure of negotiations in a value chain affects the distribution of value among its members. To this end, we generalize the Shapley value and the core to hierarchical bargaining situations. While the core yields no concrete predictions, the Shapley value analysis suggests that positions most conducive to value capture are those that allow to realize large complementarity gains. If the game exhibits “supercomplementarity,” then it is advantageous if a firm's negotiation partners are grouped into clusters. Using examples from the aircraft and white goods industries, we assess whether the firms’ actions are consistent with model predictions.     

Feasible sets,comparative risk aversion,and comparative uncertainty aversion in bargaining

We study feasible sets of the bargaining problem under two different assumptions: the players are subjective expected utility maximizers or the players are Choquet expected utility maximizers. For the latter case, we consider the effects on bargaining solutions when players become more risk averse and when they become more uncertainty averse.     

风险管理能力对物流企业动态联盟利益分配影响研究

在物流企业动态联盟中,合理的利益分配对于联盟的成功运作具有十分重要的意义。文章在使用Shapley值法计算物流企业动态联盟成员企业间利益分配的基础上,引入了风险管理能力因素,并利用模糊综合评判法进行量化,使Shapley值法的利益分配结果得到了更加合理的修正,能够从风险管理能力角度更好地把握物流企业动态联盟成员企业间利益分配的合理性。     

On the existence of an increasing symmetric equilibrium in (k + 1)-st price common value auctions

In a classical result, Milgrom (1981a) established that the Monotone Likelihood Ratio Property (MLRP) is a sufficient condition for the existence of an increasing symmetric equilibrium in (k + 1)-st price common value auctions. We show: (1) If MLRP is violated, then for any number of bidders and objects there exists a distribution of the common value such that no increasing symmetric equilibrium exists; (2) If MLRP is violated, then for any distribution of the common value there exist infinitely many pairs of the number of bidders and the number of objects such that an increasing symmetric equilibrium does not exist; (3) There are examples where an increasing symmetric equilibrium exists even when the signal distribution violates MLRP.     

Government and governance: The value of project management in the public sector

Governance is an emerging theme that has been associated in the public sector with a real political need to satisfy stakeholders by demonstrating accountability and transparency while effectively implementing policy. Many initiatives relating to governance are generated by a need for improvement of organizational performance and ability to implement and adapt to change. These generally take the form of projects and programs encouraging a variety of project management implementations in the public sector. This article reports on examination of the expectations and realization of value from investment in project management in four Australian public‐sector organizations with particular reference to the government context, the perspective of public value management (PVM), and the support that project management provides in meeting the demands of public‐sector governance.     

基于Shapley值法的供应链联盟利益分配优化研究

供应链联盟利益如何分配是关系到联盟稳定性和能否使联盟整体效益达到最优的关键问题之一。文章考虑到联盟中部分企业间存在的联结依赖关系及这种关系能够给联盟带来额外收益,针对应用Shapley值法进行供应链联盟利益分配时的不足．提出了一种新的Shapley值修正算法。最后通过算例证明该策略不仅保证了联盟的稳定性,而且使得联盟整体收益得到优化。