In economics, markets also serve to aggregate information through relative prices. There are no relative prices explicit in elections, yet it is not only implausible to presume voters know the true size of the electorate, it is also implausible that they know the full implications of electing one candidate rather than another. Because the likelihood that any single vote is pivotal in a large election is negligible, the incentives for any one voter in a large electorate to invest in becoming better informed regarding the candidates for election are likewise negligible.
In particular, an instrumentally rational voter conditions her vote on the event that she is pivotal; and in the presence of asymmetric information throughout the electorate, conditioning on the event of being pivotal can yield a great deal of information about what others know. To see this, consider an example in which two candidates are competing for a majority of votes in a three-person electorate. Suppose each voter receives a noisy private signal correlated with which of the two candidates would be best and for simplicity suppose further that all voters share identical full-information preferences.
Now if the first two voters are voting sincerely relative to their signals and the third voter is pivotal, it must be the case that the first two voters have received conflicting information about the candidates, in which case the third voter can base her vote on all of the available information distributed through the electorate, even though that distribution was not publicly known.
Exactly what are the information aggregation properties of various electoral schemes is currently subject to much research. In some settings, the logic sketched above can yield quite perverse results; for example, Ordeshook and Palfrey provide an example in which an almost sure Condorcet winner that is, an alternative against which no alternative is preferred by a strict majority is surely defeated in an amendment agenda with incomplete information. And in other settings, it turns p. To all intents and purposes, the methods of contemporary positive political theory coincide with the methods of contemporary economic theory.
More recently, the growth of interest in behavioral economics, experimental research, and so forth is beginning to appear in the political science literature. Rather than sketch these and other applications of economic methods to political science, this chapter attempts to articulate a broader likely idiosyncratic view of positive political theory since the importation of formal rational choice theory to politics. After all, political decision-making has at least as much of a claim to being subject to rational choice as economic decision-making; political agents make purposive decisions to promote their interests subject to constraints.
It would be odd, then, to discover that the methods of economics are of no value to the study of politics. Arrow, K. Social Choice and Individual Values. New Haven, Conn. Find this resource:. Social Choice and Individual Values , 2nd edn. Elections, coalitions and legislative outcomes. American Political Science Review , — Social choice theory, game theory and positive political theory. In Annual Review of Political Science , vol. Palo Alto, Calif: Annual Reviews. Positive Political Theory , i: Collective Preference. Ann Arbor: University of Michigan Press.
Positive Political Theory , ii: Strategy and Structure. Banks, J. Sophisticated voting outcomes and agenda control. Social Choice and Welfare , 1: — Baron, D. A sequential choice perspective on legislative organization. Legislative Studies Quarterly , — Bernheim, D. Common agency. Econometrica , — Besley, T.
An economic model of representative democracy. Quarterly Journal of Economics , 85— Black, D. The Theory of Committees and Elections. Cambridge: Cambridge University Press. Cox, G. Centripetal and centrifugal incentives in electoral systems. American Journal of Political Science , — Strategic voting equilibria under the single nontransferable vote. Crawford, V. Strategic information transmission.
Davis, O. A mathematical model of policy formation in a democratic society. In Mathematical Applications in Political Science , ii, ed. Dallas, Tex. Southern Methodist University Press. Some results related to a mathematical model of policy formation in a democratic society. In Mathematical Applications in Political Science , iii, ed. An expository development of a mathematical model of the electoral process. Diermeier, D. Explanatory concepts in formal political theory. Mimeo, Stanford University. A structural model of government formation. Econometrica , 27— Downs, A.
An Economic Theory of Democracy. New York: Harper. Feddersen, T. American Economic Review , — Ferejohn, J. Closeness counts only in horseshoes and dancing. American Political Science Review , —5.
Fudenberg, D. Game Theory. Cambridge, Mass. Harsanyi, J. Management Science , —82, —34, — Hotelling, H. Stability in competition. Economic Journal , 41— Ledyard, J. The pure theory of large two-candidate elections. Public Choice , 7— McLean, I. The Borda and Condorcet principles: three medieval applications.
Social Choice and Welfare , 7: 99— McKelvey, R. Intransitivities in multidimensional voting models and some implications for agenda control. Journal of Economic Theory , — General conditions for global intransitivities in formal voting models. Covering, dominance and institution-free properties of social choice. Generalized symmetry conditions at a core point. May, K. A set of independent necessary and sufficient conditions for simple majority decision.
Econometrica , —4. Miller, N. A new solution set for tournaments and majority voting. American Journal of Political Science , 68— Committees, Agendas and Voting. Chur: Harwood Academic. Myerson, R. Game Theory: Analysis of Conflict. Population uncertainty and Poisson games. International Journal of Game Theory , — Theoretical comparisons of electoral systems.
European Economic Review , — Large Poisson games.
Evolutionary Game Theory
Series description. How do series work? Helpers Avron 16 , wwittler77 1. This particular view of game theory hascome under recent criticism. First, it is criticized because the assumptions made by game theorists areoften violated. Game theorists may assume players always act in a way to directly maximize their wins the Homo economicus model , but in practice, human behavior often deviates from this model. Explanations of this phenomenon are many; irrationality, new models of deliberation, or even differentmotives like that of altruism.
Game theorists respond by comparing their assumptions to those used inphysics. Thus while their assumptions do not always hold, they can treat game theory as a reasonablescientific ideal akin to the models used by physicists.
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However, additional criticism of this use of gametheory has been levied because some experiments have demonstrated that individuals do not playequilibrium strategies. There is an ongoing debate regarding theimportance of these experiments. Alternatively, some authors claim that Nash equilibria do not provide predictions for human populations,but rather provide an explanation for why populations that play Nash equilibria remain in that state.
However, the question of how populations reach those points remains open. Some game theorists have turned to evolutionary game theory in order to resolve these issues.
Thesemodels presume either no rationality or bounded rationality on the part of players. Despite the name,evolutionary game theory does not necessarily presume natural selection in the biological sense. Evolutionary game theory includes both biological as well as cultural evolution and also models ofindividual learning for example, fictitious play dynamics.
Prescriptive or normative analysisOn the other hand, some scholars see game theory not as a Cooperate Defectpredictive tool for the behavior of human beings, but as asuggestion for how people ought to behave. Since a Nashequilibrium of a game constitutes ones best response to the actions Cooperate -1, -1 , 0of the other players, playing a strategy that is part of a Nashequilibrium seems appropriate. However, this use for game theory Defect 0, -5, -5has also come under criticism. First, in some cases it is appropriateto play a non-equilibrium strategy if one expects others to play non- The Prisoners Dilemmaequilibrium strategies as well.
Second, the Prisoners dilemma presents another potential counterexample. In the Prisoners Dilemma,each player pursuing his own self-interest leads both players to be worse off than had they not pursuedtheir own self-interests. Economics and businessGame theory is a major method used in mathematical economics and business for modeling competingbehaviors of interacting agents.
Applications include a wide array of economic phenomena andapproaches, such as auctions, bargaining, fair division, duopolies, oligopolies, social network formation,agent-based computational economics, general equilibrium, mechanism design, and voting systems, andacross such broad areas as experimental economics, behavioral economics, information economics,industrial organization, and political economy.
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This research usually focuses on particular sets of strategies known as equilibria in games. These"solution concepts" are usually based on what is required by norms of rationality. In non-cooperativegames, the most famous of these is the Nash equilibrium. A set of strategies is Nash equilibrium if eachrepresents a best response to the other strategies. So, if all the players are playing the strategies in aNash equilibrium, they have no unilateral incentive to deviate, since their strategy is the best they can dogiven what others are doing.
The payoffs of the game are generally taken to represent the utility of individual players. Often inmodeling situations the payoffs represent money, which presumably corresponds to an individuals utility. This assumption, however, can be faulty. A prototypical paper on game theory in economics begins by presenting a game that is an abstraction ofsome particular economic situation. One or more solution concepts are chosen, and the authordemonstrates which strategy sets in the presented game are equilibria of the appropriate type.
Naturallyone might wonder to what use this information should be put. Economists and business professorssuggest two primary uses: descriptive and prescriptive. Political scienceThe application of game theory to political science is focused in the overlapping areas of fair division,political economy, public choice, war bargaining, positive political theory, and social choice theory. Ineach of these areas, researchers have developed game-theoretic models in which the players are oftenvoters, states, special interest groups, and politicians.
For early examples of game theory applied to political science, see the work of Anthony Downs.
In hisbook An Economic Theory of Democracy Downs , he applies the Hotelling firm location model tothe political process. In the Downsian model, political candidates commit to ideologies on a one-dimensional policy space. Downs first shows how the political candidates will converge to the ideologypreferred by the median voter if voters are fully informed, but then argues that voters choose to remainrationally ignorant which allows for candidate divergence. A game-theoretic explanation for democratic peace is that public and open debate in democracies sendsclear and reliable information regarding their intentions to other states.
In contrast, it is difficult to knowthe intentions of nondemocratic leaders, what effect concessions will have, and if promises will be kept. Thus there will be mistrust and unwillingness to make concessions if at least one of the parties in adispute is a non-democracy. BiologyUnlike economics, the payoffs for games in biology are often Hawk Doveinterpreted as corresponding to fitness.
In addition, the focus hasbeen less on equilibria that correspond to a notion of rationality, butrather on ones that would be maintained by evolutionary forces. Although its initial motivation did not involve any of themental requirements of the Nash equilibrium, every ESS is a Nash The hawk-dove gameequilibrium. In biology, game theory has been used to understand many different phenomena. It was first used toexplain the evolution and stability of the approximate sex ratios. Fisher suggested that the sex ratios are a result of evolutionary forces acting on individuals who could be seen as trying tomaximize their number of grandchildren.
The analysis of signaling games and othercommunication games has provided some insight into the evolution of communication among animals. For example, the mobbing behavior of many species, in which a large number of prey animals attack alarger predator, seems to be an example of spontaneous emergent organization.
Ants have also beenshown to exhibit feed-forward behavior akin to fashion, see Butterfly Economics. Biologists have used the game of chicken to analyze fighting behavior and territorialityMaynard Smith, in the preface to Evolution and the Theory of Games, writes, "Paradoxically, it has turnedout that game theory is more readily applied to biology than to the field of economic behavior for which itwas originally designed". Evolutionary game theory has been used to explain many seeminglyincongruous phenomena in nature. One such phenomenon is known as biological altruism. This is a situation in which an organism appearsto act in a way that benefits other organisms and is detrimental to it.
This is distinct from traditionalnotions of altruism because such actions are not conscious, but appear to be evolutionary adaptations to 7. Examples can be found in species ranging from vampire bats that regurgitateblood they have obtained from a nights hunting and give it to group members who have failed to feed, toworker bees that care for the queen bee for their entire lives and never mate, to Vervet monkeys thatwarn group members of a predators approach, even when it endangers that individuals chance ofsurvival.
All of these actions increase the overall fitness of a group, but occur at a cost to the individual. Evolutionary game theory explains this altruism with the idea of kin selection. Altruists discriminatebetween the individuals they help and favor relatives.
The more closely related twoorganisms are causes the incidences of altruism to increase because they share many of the samealleles. This means that the altruistic individual, by ensuring that the alleles of its close relative are passedon, through survival of its offspring can forgo the option of having offspring itself because the samenumber of alleles are passed on. Similarly if it is considered that information other than thatof a genetic nature e. Computer science and logicGame theory has come to play an increasingly important role in logic and in computer science.
Severallogical theories have a basis in game semantics. In addition, computer scientists have used games tomodel interactive computations. Also, game theory provides a theoretical basis to the field of multi-agentsystems. Separately, game theory has played a role in online algorithms.
In particular, the k-server problem, whichhas in the past been referred to as games with moving costs and request-answer games. Yaos principleis a game-theoretic technique for proving lower bounds on the computational complexity of randomizedalgorithms, and especially of online algorithms. The emergence of the internet has motivated the development of algorithms for finding equilibria ingames, markets, computational auctions, peer-to-peer systems, and security and information markets.
Algorithmic game theory and within it algorithmic mechanism design combine computational algorithmdesign and analysis of complex systems with economic theory. PhilosophyGame theory has been put to several uses in philosophy. Stag HareResponding to two papers by W. Quine , , Lewis used game theory to develop a philosophical account ofconvention.
Signaling Games in Political Science - Jeffrey Banks, Jeffrey S. Banks - Google книги
In so doing, he provided the first analysis of common Stag 3, 3 0, 2knowledge and employed it in analyzing play in coordination games. In addition, he first suggested that one can understand meaning in Hare 2, 0 2, 2terms of signaling games. Following Lewis game-theoreticaccount of conventions, Ullmann Margalit and Bicchieri have developed theories of socialnorms that define them as Nash equilibria that result from transforming a mixed-motive game into acoordination game.
Game theory has also challenged philosophers to think in terms of interactive epistemology: what itmeans for a collective to have common beliefs or knowledge, and what are the consequences of thisknowledge for the social outcomes resulting from agents interactions. Philosophers who have worked inthis area include Bicchieri , , Skyrms , and Stalnaker In ethics, some authors have attempted to pursue the project, begun by Thomas Hobbes, of derivingmorality from self-interest. Since games like the Prisoners dilemma present an apparent conflict betweenmorality and self-interest, explaining why cooperation is required by self-interest is an importantcomponent of this project.
This general strategy is a component of the general social contract view inpolitical philosophy for examples, see Gauthier and Kavka Other authors have attempted to use evolutionary game theory in order to explain the emergence ofhuman attitudes about morality and corresponding animal behaviors. These authors look at severalgames including the Prisoners dilemma, Stag hunt, and the Nash bargaining game as providing anexplanation for the emergence of attitudes about morality see, e. Some assumptions used in some parts of game theory have been challenged in philosophy;psychological egoism states that rationality reduces to self-interest—a claim debated amongphilosophers.
Types of gamesCooperative or non-cooperativeA game is cooperative if the players are able to form binding commitments. For instance the legal systemrequires them to adhere to their promises. In non cooperative games this is not possible. Often it is assumed that communication among players is allowed in cooperative games, but not in noncooperative ones. However, this classification on two binary criteria has been questioned, and sometimesrejected Harsanyi Of the two types of games, non cooperative games are able to model situations to the finest details,producing accurate results.
Cooperative games focus on the game at large. Considerable efforts havebeen made to link the two approaches. The so-called Nash-program has already established many of thecooperative solutions as non cooperative equilibria.