
on Game Theory 
Issue of 2013‒12‒15
28 papers chosen by Laszlo A. Koczy Hungarian Academy of Sciences and Obuda University 
By:  Feltkamp, Vicent; Arin Aguirre, Francisco Javier; Montero García, María 
Abstract:  This paper studies an allocation procedure for coalitional games with veto players. The procedure is similar to the one presented by Dagan et al. (1997) for bankruptcy problems. According to it, a player, the proposer, makes a proposal that the remaining players must accept or reject, and con ict is solved bilaterally between the rejector and the proposer. We allow the proposer to make sequential proposals over several periods. If responders are myopic maximizers (i.e. consider each period in isolation), the only equilibrium outcome is the serial rule of Arin and Feltkamp (2012) regardless of the order of moves. If all players are farsighted, the serial rule still arises as the unique subgame perfect equilibrium outcome if the order of moves is such that stronger players respond to the proposal after weaker ones. 
Keywords:  veto players, bargaining, myopic behavior, serial rule 
JEL:  C72 C78 C71 D70 
Date:  2013–10–10 
URL:  http://d.repec.org/n?u=RePEc:ehu:ikerla:11102&r=gth 
By:  Sebastien Courtin (THEMA  Théorie économique, modélisation et applications  CNRS : UMR8184  Université de Cergy Pontoise); Bertrand Tchantcho (THEMA  Théorie économique, modélisation et applications  CNRS : UMR8184  Université de Cergy Pontoise) 
Abstract:  The desirability relation was introduced by Isbell (1958) to qualitatively compare the a priori influence of voters in a simple game. In this paper, we extend this desirability relation to simple games with coalition structure. In these games, players organize themselves into a priori disjoint coalitions. It appears that the desirability relation defined in this paper is a complete preorder in the class of swaprobust games. We also compare our desirability relation with the preorders induced by the generalizations to games with coalition structure of the ShapleyShubik and BanzahfColeman power indices (Owen, 1977, 1981). It happens that in general they are different even if one considers the subclass of weighed voting games. However, if structural coalitions have equal size then both OwenBanzhaf and the desirability preordering coincide. 
Date:  2013–12–06 
URL:  http://d.repec.org/n?u=RePEc:hal:wpaper:hal00914910&r=gth 
By:  Rosenberg, Dinah; Salomon , Antoine; Vieille , Nicolas 
Abstract:  We study a class of symmetric strategic experimentation games. Each of two players faces a (exponential) twoarmed bandit problem, and must decide when to stop experimenting with the risky arm. The equilibrium amount of experimentation depends on the degree to which experimentation outcomes are observed, and on the correlation between the two individual bandit problems. When experimentation outcomes are public, the game is basically one of strategic complementarities. When experimentation decisions are public, but outcomes are private, the strategic interaction is more complex. We fully characterize the equilibrium behavior in both informational setups, leading to a clear comparison between the two. In particular, equilibrium payoffs are higher when equilibrium outcomes are public. 
Keywords:  symmetric strategic experimentation games; equilibrium; strategic experimentation 
JEL:  C00 
Date:  2013–10–24 
URL:  http://d.repec.org/n?u=RePEc:ebg:heccah:1008&r=gth 
By:  Dirk Bergemann (Cowles Foundation, Yale University); Tibor Heumann (Dept. of Economics, Yale University); Stephen Morris (Dept. of Economics, Princeton University) 
Abstract:  We analyze a class of games with interdependent values and linear best responses. The payoff uncertainty is described by a multivariate normal distribution that includes the pure common and pure private value environment as special cases. We characterize the set of joint distributions over actions and states that can arise as Bayes Nash equilibrium distributions under any multivariate normally distributed signals about the payoff states. We characterize maximum aggregate volatility for a given distribution of the payoff states. We show that the maximal aggregate volatility is attained in a noisefree equilibrium in which the agents confound idiosyncratic and common components of the payoff state, and display excess response to the common component. We use a general approach to identify the critical information structures for the Bayes Nash equilibrium via the notion of Bayes correlated equilibrium, as introduced by Bergemann and Morris (2013b). 
Keywords:  Incomplete information, Bayes correlated equilibrium, Volatility, moments restrictions, Linear best responses, Quadratic payoffs 
JEL:  C72 C73 D43 D83 
Date:  2013–12 
URL:  http://d.repec.org/n?u=RePEc:cwl:cwldpp:1928&r=gth 
By:  Sylvain Béal (CRESE, Université de FrancheComté); Eric Rémila (Gate Lyon SaintEtienne, Université de Saintetienne); Philippe Solal (Gate Lyon SaintEtienne, Université de Saintetienne) 
Abstract:  If a player is removed from a game, what keeps the payoff of the remaining players unchanged? Is it the removal of a special player or its presence among the remaining players? This article answers this question in a complement study to Kamijo and Kongo (2012). We introduce axioms of invariance from player deletion in presence of a special player. In particular, if the special player is a nullifying player (resp. dummifying player), then the equal division value (resp. equal surplus division value) is characterized by the associated axiom of invariance plus efficiency and balanced cycle contributions. There is no type of special player from such a combination of axioms that characterizes the Shapley value. 
Keywords:  weighted division values, equal division, weighted surplus division values, equal surplus division, Shapley value, null player, nullifying player, dummifying player, invariance from player deletion in presence of a special player 
JEL:  C71 
Date:  2013–11 
URL:  http://d.repec.org/n?u=RePEc:crb:wpaper:201309&r=gth 
By:  Rindone, Fabio; Greco, Salvatore; Di Gaetano, Luigi 
Abstract:  The aim of this paper is to introduce prospect theory in a game theoretic framework. We address the complexity of the weighting function by restricting the object of our analysis to a 2player 2strategy game, in order to derive some core results. We find that dominant and indifferent strategies are preserved under prospect theory. However, in absence of dominant strategies, equilibrium may not exist depending on parameters. We also discuss a different approach presented by Metzger and Rieger (2009) and give some interesting interpretations of the two approaches. 
Keywords:  Game theory, Prospect theory, Nash equilibrium, Behavioural economics. 
JEL:  C7 C70 D03 
Date:  2013–06–06 
URL:  http://d.repec.org/n?u=RePEc:pra:mprapa:52131&r=gth 
By:  Cardaliaguet, Pierre; Rainer, Catherine; Rosenberg, Dinah; Vieille , Nicolas 
Abstract:  We study a twoplayer, zerosum, stochastic game with incomplete information on one side in which the players are allowed to play more and more frequently. The informed player observes the realization of a Markov chain on which the payoffs depend, while the noninformed player only observes his opponent's actions. We show the existence of a limit value as the time span between two consecutive stages vanishes; this value is characterized through an auxiliary optimization problem and as the solution of an HamiltonJacobi equation. 
Keywords:  stochastic; zero sum; Markov chain; HamiltonJacobi equation; incomplete information 
JEL:  C00 
Date:  2013–10–24 
URL:  http://d.repec.org/n?u=RePEc:ebg:heccah:1007&r=gth 
By:  Vilella Bach, Misericòrdia 
Abstract:  In this paper we study the equity core (Selten, 1978) and compare it with the core. A payo vector is in the equity core if no coalition can divide its value among its members proportionally to a given weight system and, in this way, give more to each member than the amount he or she receives in the payo vector. We show that the equity core is a compact extension of the core and that, for nonnegative games, the intersection of all equity cores with respect to all weights coincides with the core of the game. Keywords: Cooperative game, equity core, equal division core, core. JEL classi cation: C71 
Keywords:  Jocs cooperatius, 33  Economia, 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:urv:wpaper:2072/220760&r=gth 
By:  Emanuele Gerratana (SIPA, Columbia University); Levent Koçkesen (Department of Economics, Koç University) 
Abstract:  This paper characterizes equilibrium outcomes of extensive form games with incomplete information in which players can sign renegotiable contracts with thirdparties. Our aim is to understand the extent to which thirdparty contracts can be used as commitment devices when it is impossible to commit not to renegotiate them. We characterize renegotiationproof contracts and strategies for general extensive form games with incomplete information and apply our results to twostage games. If contracts are observable, then the second mover obtains her best possible payoff given that she plays a renegotiationproof strategy and the first mover best responds. If contracts are unobservable, then a “folk theorem” type result holds: Any outcome in which the second mover best responds to the first mover’s action on the equilibrium path and the first mover receives at least his “individually rational payoff”, can be supported. We also apply our results to games with monotone externalities and to a model of credibility of monetary policy and show that in both cases renegotiationproofness imposes a very simple restriction. 
Keywords:  ThirdParty Contracts, Commitment, Strategic Delegation, Renegotiation, Asymmetric Information, RenegotiationProofness, EntryDeterrence,Monetary Policy. 
JEL:  C72 D80 L13 
Date:  2013–12 
URL:  http://d.repec.org/n?u=RePEc:koc:wpaper:1323&r=gth 
By:  Ramón Jesús Flores Díaz; Elisenda Molina; Juan Tejada 
Abstract:  Following the original interpretation of the Shapley value (Shapley, 1953a) as a priori evaluation of the prospects of a player in a multiperson iteraction situation, we propose a group value, which we call the Shapley group value, as a priori evaluation of the prospects of a group of players in a coalitional game when acting as a unit. We study its properties and we give an axiomatic characterization. We motivate our proposal by means of some relevant applications of the Shapley group value, when it is used as an objective function by a decision maker who is trying to identify an optimal group of agents in a framework in which agents interact and the attained benefit can be modeled by means of a transferable utility game. As an illustrative example we analyze the problem of identifying the set of key agents in a terrorist network. 
Keywords:  Game Theory , TU games , Shapley value , Group values 
Date:  2013–11 
URL:  http://d.repec.org/n?u=RePEc:cte:wsrepe:ws133430&r=gth 
By:  Ulrich Faigle (Universität zu Köln  Mathematisches Institut); Michel Grabisch (CES  Centre d'économie de la Sorbonne  CNRS : UMR8174  Université Paris I  PanthéonSorbonne, EEPPSE  Ecole d'Économie de Paris  Paris School of Economics  Ecole d'Économie de Paris) 
Abstract:  The Shapley value is defined as the average marginal contribution of a player, taken over all possible ways to form the grand coalition $N$ when one starts from the empty coalition and adds players one by one. The authors have proposed in a previous paper an allocation scheme for a general model of coalition formation where the evolution of the coalition of active players is ruled by a Markov chain, and need not finish at the grand coalition. The aim of this note is to develop some explanations in the general context of time discrete stochastic processes, exhibit new properties of the model, correct some inaccuracies in the original paper, and give a new version of the axiomatization. 
Keywords:  coalitional game; coalition formation process; Shapley value 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:hal:cesptp:halshs00912889&r=gth 
By:  JeanDaniel Guigou; Bruno Lovat; Marc Boissaux (LSF) 
Abstract:  We study a rentseeking proprtionalprize contest between two heterogeneously riskaverse players and given prize amounts are normally distributed rather than known ex ante. We establish existence and unicity of a Nash equilibrium linked to this contest, and study the equilibrium e_orts implied. We then obtain a similar equilibrium result for a winnertakesall lottery contest within the same risky rent context, and compare optimal e_orts as well as expected utilities between the two contest types. 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:crf:wpaper:139&r=gth 
By:  Gall, Thomas 
Abstract:  Does a competitive equilibrium in a matching market provide adequate incentives for investments made before the market when utility is not perfectly transferable? This paper derives a necessary and sufficient condition for equilibrium investments to maximize surplus conditional on the matching assignment in a onesided market. Surplus efficiency of equilibrium payoffs ex post alone is sufficient for surplus efficient investments only when the equal treatment property holds in equilibrium. Sufficient (but not full) utility transferability in a well defined sense ensures this will hold and that a social planner who can only change investments cannot achieve higher aggregate surplus than the market. Keywords; matching, assignment models, investments, nontransferable utility, graph theory 
Date:  2013–07–08 
URL:  http://d.repec.org/n?u=RePEc:stn:sotoec:360186&r=gth 
By:  Sebastien Courtin (THEMA  Théorie économique, modélisation et applications  CNRS : UMR8184  Université de Cergy Pontoise); Matias Nunez (THEMA  Théorie économique, modélisation et applications  CNRS : UMR8184  Université de Cergy Pontoise) 
Abstract:  This work provides necessary and sufficient conditions for the dominance solvability of approval voting games. Our conditions are very simple since they are based on the approval relation, a binary relation between the alternatives. We distinguish between two sorts of dominance solvability and prove that the most stringent one leads to the election of the set of Condorcet Winners whereas this need not be the case for the weak version. 
Date:  2013–12–06 
URL:  http://d.repec.org/n?u=RePEc:hal:wpaper:hal00914890&r=gth 
By:  Cason, Timothy; Sheremeta, Roman; Zhang, Jingjing 
Abstract:  Costless preplay communication has been found to effectively facilitate coordination and enhance efficiency in games with Paretoranked equilibria. We report an experiment in which two groups compete in a weakestlink contest by expending costly efforts. Allowing intragroup communication leads to more aggressive competition and greater coordination than control treatments without any communication. On the other hand, allowing intergroup communication leads to less destructive competition. As a result, intragroup communication decreases while intergroup communication increases payoffs. Our experiment thus provides an example of an environment where communication can either enhance or damage efficiency. This contrasts sharply with experimental findings from public goods and other coordination games, where communication always enhances efficiency and often leads to socially optimal outcomes. 
Keywords:  contest, betweengroup competition, withingroup competition, cooperation, coordination, freeriding, experiments 
JEL:  C70 D72 H41 
Date:  2012 
URL:  http://d.repec.org/n?u=RePEc:pra:mprapa:52107&r=gth 
By:  Matias Nunez (THEMA  Théorie économique, modélisation et applications  CNRS : UMR8184  Université de Cergy Pontoise) 
Abstract:  We show that Approval voting need not trigger sincere behavior in equilibrium of Poisson voting games and hence might lead a strategic voter to skip a candidate preferred to his worst preferred approved candidate. We identify two main rationales for these violations of sincerity. First, if a candidate has no votes, a voter might skip him. Notwithstanding, we provide sufficient conditions on the voters' preference intensities to remove this sort of insincerity. On the contrary, if the candidate gets a positive share of the votes, a voter might skip him solely on the basis of his ordinal preferences. This second type of insincerity is a consequence of the correlation of the candidates' scores. The incentives for sincerity of rank scoring rules are also discussed. 
Keywords:  Sincerity Approval voting Poisson games 
Date:  2013–09 
URL:  http://d.repec.org/n?u=RePEc:hal:journl:hal00917101&r=gth 
By:  Alessandro Tampieri (CREA, University of Luxembourg) 
Abstract:  In this paper we study marriage formation through a twosided secretary problem approach. We consider individuals with non transferable utility and two different dimensions of heterogeneity, a characteristic evaluated according to the idiosyncratic preferences of potential partners, and a universallyrankable characteristic. There are two possible states of the world, one in which people meet their partner randomly, and one in which the meeting occurs between individuals with similar characteristics. We show that individuals with higher universal characteristic tend to be more picky in their marriage hunting. This does not necessarily mean that they marry later than other individuals, since the higher expected quality of their potential partners in the assortative meeting state can make them marry earlier than individuals with a lower universal characterictic. 
Keywords:  secretary problem, random meeting, assortative meeting 
JEL:  C73 C78 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:luc:wpaper:1329&r=gth 
By:  Charness, Gary; Feri, Francesco; MelÃ©ndezJimÃ©nez, Miguel A; Sutter, Matthias 
Keywords:  Social and Behavioral Sciences 
Date:  2013–07–22 
URL:  http://d.repec.org/n?u=RePEc:cdl:ucsbec:qt6m0584qv&r=gth 
By:  José Pedro Pontes; Joana Pais 
Abstract:  This paper addresses the issue of industrial development using a coordination game. Complementarities between transport infrastructure provision by the Government and consumer goods manufacturing firms, and among consumer goods firms themselves dictate the outcome: either the transport infrastructure (i.e., a highway) is not built and firms keep doing “home” production, thus supplying mainly nearby consumers and dispensing with a highway; or they switch to “factory” production, a more spatially centralized regime, where output must be sold over long distances, thus implying the construction of a highway. In relation to the existent literature, this paper presents two main innovations. Firstly, the two sources of linkage, namely cost linkage, through the provision of an indivisible input (the highway), and demand linkage, through the wage rise brought about by industrialization, are not treated separately, but they are integrated in the same model. Consequently, the game has now two levels of equilibrium selection. Secondly, the paper does not limit itself to checking that there can arise multiple Nash equilibria under certain circumstances, but it discusses methods for the selection of a unique outcome. Consequently, in addition to the classical Nash equilibria mentioned above, there is a third possible solution where the Government builds the highway but the consumer goods firms refrain from using it and stick to “home” production. Hence, the transport infrastructure becomes a “white elephant”. 
Keywords:  Big Push, Coordination Games, Economic Development, Equilibrium selection, Industrialization. 
JEL:  C72 O12 O14 
Date:  2013–12 
URL:  http://d.repec.org/n?u=RePEc:ise:isegwp:wp292013&r=gth 
By:  Subiza, Begoña (Universidad de Alicante, Departamento de Métodos Cuantitativos y Teoría Económica); SilvaReus, José Ángel (Instituto Interuniversitario de Desarrollo Social y Paz); Peris, Josep E. (Universidad de Alicante, Departamento de Métodos Cuantitativos y Teoría Económica) 
Abstract:  We consider a cost sharing problem, where each individual is identi ed by a characteristic (a positive real number) ci: The two main positions on how to share a common cost M are the Egalitarian and the Proportional solutions. These solutions can be obtained as the Perron's eigenvectors (right and left, respectively) of a characteristics matrix A, with rk(A) = 1; de fined from the individuals' characteristics ci: Then, the right Perron's eigenvector associated to any Levinger's transformation L(α) = α A'+(1α )A; α є [0;1] ; provides a dif ferent solution to the cost sharing problem (from the egalitarian one, for α = 0; to the proportional one, for α = 1). We are interested in analyzing the properties of the components of these Perron's eigenvectors as (non linear) functions of the parameter α that de fines the convex combination of matrices A and A': These components de fine the solution of the cost sharing problem, that could be understood as a compromise between the egalitarian and proportional approaches. We prove that when the associated positive eigenvector is normalized, its components have a monotone behaviour in the unit interval [0;1]: Additional properties and a way of selecting a particular compromise solution are provided. 
Keywords:  Cost Sharing; Egalitarian; Proportional; Perrons Eigenvector; Compromise Solution 
JEL:  C71 D63 D71 
Date:  2013–12–10 
URL:  http://d.repec.org/n?u=RePEc:ris:qmetal:2013_006&r=gth 
By:  Dino Gerardi; Lucas Maestri 
Abstract:  A seller dynamically sells a divisible good to a buyer. It is common knowledge that there are gains from trade and that the gains per unit are decreasing. Payoffs are interdependent as in Akerlof's market for lemons. The seller is informed about the good's quality. The buyer makes an offer in every period and learns about the good's quality only through the seller's behavior. We characterize the stationary equilibrium when the time between offers is small. The owner of a highquality good sells it in dribs and drabs, whereas the owner of a lowquality good constantly randomizes between selling small pieces and accepting an offer for all the remaining units. We use this characterization to analyze the limiting equilibrium outcome as the good becomes more divisible. We prove that there is slow trading: a valuable good is smoothly sold over time. In contrast, the good is never partially sold when gains per unit are increasing. 
JEL:  C78 D82 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:cca:wpaper:312&r=gth 
By:  Thomas Eichner; Rüdiger Pethig 
Abstract:  In the basic model of international environmental agreements (IEAs) (Barrett 1994, Rubio and Ulph 2006) extended by international trade, self enforcing  or stable  IEAs may comprise up to 60% of all countries (Eichner and Pethig 2013). But these IEAs reduce total emissions only slightly compared to noncooperation. Here we analyze the capacity of signunconstrained tariffs to enhance the size and performance of selfenforcing IEAs. We show that the size of stable IEAs shrinks when climate coalitions are Stackelberg leaders and set tariffs in addition to their capandtrade schemes. Surprisingly, these smaller IEAs reduce total emissions more effectively than the larger stable IEAs without tariffs. In the model with tariffs the signatory countries import fossil fuel and their tariff takes the form of a subsidy of fuel consumption and a tax on the production of the consumption good. 
Keywords:  tariff, trade, selfenforcing environmental agreements, Stackelberg equilibrium 
JEL:  C72 F18 Q50 Q58 
Date:  2013 
URL:  http://d.repec.org/n?u=RePEc:sie:siegen:16113&r=gth 
By:  Friedrich Poeschel 
Abstract:  When agents do not know where to find a match, they search. However, agents could direct their search to agents who strategically choose a certain signal. Introducing cheap talk to a model of sequential search with bargaining, we find that signals will be truthful if there are mild complementarities in match production: supermodularity of the match production function is a necessary and sufficient condition. It simultaneously ensures perfect positive assortative matching, so that singlecrossing property and sorting condition coincide. As the information from signals allows agents to avoid all unnecessary search, this search model exhibits nearly unconstrained efficiency. 
JEL:  J64 D83 C78 
Date:  2013–12–07 
URL:  http://d.repec.org/n?u=RePEc:jmp:jm2013:ppo178&r=gth 
By:  Renou , Ludovic; Tomala, Tristan 
Abstract:  This paper considers dynamic implementation problems with evolving private information (according to Markov processes). A social choice function is approximately implementable if there exists a dynamic mechanism such that the social choice function is implemented by an arbitrary large number of times with arbitrary high probability in every communication equilibrium. We show that if a social choice function is strictly efficient in the set of social choice functions that satisfy an undetectable condition, then it is approximately implementable. We revisit the classical monopolistic screening problem and show that the monopolist can extract the full surplus in almost all periods with arbitrary high probability. 
Keywords:  implementation; Markov Process; undetectability; efficiency 
JEL:  C70 
Date:  2013–07–21 
URL:  http://d.repec.org/n?u=RePEc:ebg:heccah:1015&r=gth 
By:  Sidartha Gordon (Département d'économie); Olivier Bochet (University of Bern); René Saran 
Abstract:  We consider collective decision problems given by a profile of singlepeakedpreferences defined over the real line and a set of pure public facilities to be located on the line. In this context, Bochet and Gordon (2012) provide a large class of priority rules based on efficiency, objectpopulation monotonicity and sovereignty. Each such rule is described by a fixed priority ordering among interest groups. We show that any priority rule which treats agents symmetrically  anonymity  , respects some form of coherence across collective decision problems  reinforcement  and only depends on peak information  peakonly , is a weighted majoritarian rule. Each such rule defines priorities based on the relative size of the interest groups and specific weights attached to locations. We give an explicit account of the richness of this class of rules. 
Keywords:  Multiple Public Facilities; Priority Rules; Weighted Majori tarian Rules; ObjectPopulation Monotonicity; Sovereignty; Reinforcement; Anonymity. 
Date:  2013–10 
URL:  http://d.repec.org/n?u=RePEc:spo:wpecon:info:hdl:2441/6ggbvnr6munghes9oc5kng5b4&r=gth 
By:  Tomasz Strzalecki; Jan Werner 
Abstract:  An important implication of the expected utility model under risk aversion is that if agents have the same probability belief, then the efficient allocations under uncertainty are comonotone with the aggregate endowment, and if their beliefs are concordant, then the efficient allocations are measurable with respect to the aggregate endowment. We study these two properties of efficient allocations for models of preferences that exhibit ambiguity aversion using the concept of conditional belief, which we introduce in this paper. We provide characterizations of such conditional beliefs for the standard models of preferences used in applications. âˆ— 
URL:  http://d.repec.org/n?u=RePEc:qsh:wpaper:8325&r=gth 
By:  Wiroy Shin 
Abstract:  This paper studies an environment of simultaneous, separate, firstprice auctions for complementary goods. Agents observe private values of each good before making bids, and the complementarity between goods is explicitly incorporated in their utility. For simplicity, a model is presented with two firstprice auctions and two bidders. We show that a monotone purestrategy Bayesian Nash Equilibrium exists in the environment. 
Date:  2013–12 
URL:  http://d.repec.org/n?u=RePEc:arx:papers:1312.2641&r=gth 
By:  Taylor J. Canann (Department of Economics, Brigham Young University) 
Abstract:  I analyze the effects of network structure on vulnerability disclosure policy. My analysis finds that the structure of the network of households can greatly effect the overall welfare of the economy. Specifically, I find that the distribution of the centrality of the nodes and the radius of the network have a significant effect on the optimal policy system. 
Keywords:  Network Theory, Cyber Security, Disclosure Policy, Infromation Security, Network Centrality 
JEL:  C7 O3 
Date:  2013–12 
URL:  http://d.repec.org/n?u=RePEc:byu:byumcl:201305&r=gth 