equilibrium in justifiable strategies a model of reason based choice in extensive form games i explore the idea that people care about the justifiability of their decisions in the context of two person extensive games each player justifies his strategy s with a belief b of the opponent s strategy which is consistent with the play path and maximally plausible according to some exogenous criterion we say that s is justifiable if against the ex post criticism that some other strategy s outperforms s against b the player can argue that playing s would have exposed him to similar criticism in the opposite direction under a simplicity based plausibility criterion this concept implies systematic departures from maximizing behaviour in familiar games

reciprocity and cooperation in repeated coordination games the principled player approach abstract two long lived players play a repeated coordination game i show the restrictions on players beliefs which imply that cooperation is optimal play journal of economic literature classification number d83

sticks and carrots two incentive mechanisms supporting intra group cooperation abstract in this note we introduce two distinct incentive mechanisms that support dynamic intra group cooperation in the context of prisoner s dilemma payoffs rewards for cooperating and punishments for defection where the rewarding or punishing party may be outside the relationship

the second best core an economy with a single output and input is considered for the case of economies of scale in production equilibria are studied for a cooperative game of joint production in which goods are allocated by a price system the paper proposes a second best core in which allocations that are feasible for a coalition must be attainable by a price system existence is examined and properties of second best core allocations are analyzed copyright 1989 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

global feminization through flexible labor abstract the emphasis on structural adjustment and labor flexibility in both developing and industrialized economies is rapidly altering the nature of employment women are being substituted for men and many forms of work are being converted into the kinds of jobs traditionally geared to women international data on recent trends in female economic activity reveal that new types of labor data are needed to highlight the mechanisms of control over workers and the actual economic forms of vulnerability to which women are exposed the paper concludes by posing questions that challenge the traditional concerns of donors and policy makers in many developing countries

nash equilibrium when players account for the complexity of their forecasts abstract nash equilibrium is often interpreted as a steady state in which each player holds the correct expectations about the other players behavior and acts rationally this paper investigates the robustness of this interpretation when there are small costs associated with complicated forecasts the model consists of a two person strategic game in which each player chooses a finite machine to implement a strategy in an infinitely repeated 2 2 game with discounting i analyze the model using a solution concept called nash equilibrium with stable forecasts esf my main results concern the structure of equilibrium machine pairs they provide necessary and sufficient conditions on the form of equilibrium strategies and plays in contrast to the folk theorem these structural properties place severe restrictions on the set of equilibrium paths and payoffs for example only sequences of the one shot nash equilibrium can be generated by any esf of the repeated game of chicken

the market for quacks a group of n quacks plays a price competition game facing a continuum of patients who recover with probability whether or not they acquire a quack s treatment if patients chose rationally the market would be inactive i assume however that patients choose according to a boundedly rational procedure which re ects anecdotal reasoning this element of bounded rationality has signi cant

another century of economic science there is a widespread consensus that during the past century economic science has come of age it has developed powerful statistical tools to analyse economic data to make forecasts and to test alternative hypotheses and it has employed sophisticated mathematical techniques to articulate its theories and to prove basic theorems characterising the economy samuelson 1947 encapsulated the mid century enthusiasm for the scientific method in his classic foundations of economic analysis arguing that economics should be based on observable behaviour and testable hypotheses and with his theory of revealed preference showing how this could be done with the theory of consumers behaviour

partners or rivals strategies for the iterated prisoner s dilemma within the class of memory one strategies for the iterated prisoner s dilemma we characterize partner strategies competitive strategies and zero determinant strategies if a player uses a partner strategy both players can fairly share the social optimum but a co player preferring an unfair solution will be penalized by obtaining a reduced payoff a player using a competitive strategy never obtains less than the co player a player using a zero determinant strategy unilaterally enforces a linear relation between the two players payoffs these properties hold for every strategy used by the co player whether memory one or not

rationalizable conjectural equilibrium between nash and rationalizability abstract static equilibria can be viewed as steady states of recurring play of a game such steady states in which players do not perfectly observe the actions of others need not be nash equilibria this paper suggests a static solution concept rationalizable conjectural equilibrium that corresponds to such steady states to present it the basic model of a normal form game is enriched by specifying the signals that players get about others actions the solution is a profile of actions such that each player s action is optimal given that it is common knowledge that all players maximize utility given their signals journal of economic literature classification number c72

reputation and experimentation in repeated games with two long run players this paper considers reputation effects in a repeated game between two long run players one of whom is relatively patient and may be committed to a fixed strategy which punishes the opponent for increasingly long periods whenever inappropriate actions are taken by following this commitment strategy the more patient player can induce a sufficiently patient opponent to experiment to see whether the commitment strategy is also being followed off the equilibrium path this can guarantee the more patient player in any nash equilibrium a payoff close to the highest feasible payoff consistent with the individual rationality of the other player for an arbitrary degree of patience of the less patient player a weaker result is established the more patient player is guaranteed an average equilibrium payoff close to the static stackelberg payoff this latter result generalizes that of schmidt 1993 who established the same result for the restricted class of games of conflicting interests

reputation in repeated games with no discounting abstract i study two player infinitely repeated games with no discounting i examine how perturbations afford players opportunities to establish reputations and i determine how potential reputations lead to outcome selection in both equilibrium and non equilibrium settings the main result is the following assume that players have beliefs of countable support players only adopt forgiving strategies and players best respond to their beliefs a forgiving strategy does not punish an opponent forever then if the game is perturbed each player expects to fare at least as well as if she selected any of her perturbation strategies and the opponent played a best response journal of economic literature classification numbers c72 c73

gift giving and the evolution of cooperation gift giving is a practice common to many societies in an evolutionary model the social custom of giving gifts at the beginning of a relationship can lead to trust and cooperation the evolutionary approach makes predictions about the character of the goods that can be used as gifts for example gift goods may have little use value even at low levels of consumption although the gifts themselves are useless the institution is not

game theoretic modeling of increasing returns to scale abstract this paper surveys the analysis by means of cooperative game theory of economies in which there are increasing returns to scale in the first section necessary and sufficient conditions for the existence of a core of a general equilibrium economy are considered in the second section the partial equilibrium approach to increasing returns production which developed along with the natural monopoly literature is surveyed the close relationship between the general equilibrium and partial equilibrium approaches is emphasized

diversification multi market contact and profitability this paper analyses the relationships between diversification multi market contact and industry profitability it focuses on the link between diversification and multi market contact to show that when diversification establishes or increases the extent to which firms meet in more than one market the effect of such multi market contact is to increase the possibility that collusion emerges as an evolutionary stable strategy as a result multi market contact may increase the potential for tacit collusion and so lead to higher profitability the effects of diversification and multi market contact on the price cost margin and the rate of return to capital are estimated using a specially constructed new database for uk manufacturing industry in 1979 this database provides information on the diversification and multi market contact of 418 firms across 134 manufacturing industries thus linking firm and industry level data the results show a clear positive effect of multi market contact on industry profitability

stochastic evolutionary dynamics in the repeated prisoners dilemma i introduction the prisoners dilemma is perhaps the most widely studied of all game theory applications it is commonly employed in such diverse fields as economics political science and biology the literature primarily explores how the cooperative outcome can be sustained in the context of the repeated prisoners dilemma rpd this paper further examines the prisoners dilemma focusing on the infinite rpd played by individuals employing very simple strategies that can be thought of as rules of thumb moreover the strategies are exposed to an evolutionary process in which the best strategies survive over time while the weakest die out however a random element is incorporated to allow the rules of thumb to change the resulting dynamics prove to be very interesting generating populations whose characteristics depend on the probability of another encounter or how important the future is the prisoners dilemma has been used to model many economic problems for example green and porter 1984 use it to analyze collusion among oligopolists brander and spence 1985 to explore the use of export subsidies farrell and maskin 1989 to examine advertising among competing firms cornes and sandler 1986 37 42 to explain the provision of public goods and dixit and nalebuff 1991 115 18 to describe the conflict between congress and the federal reserve over economic policy for the purposes of this essay it is important that these situations are repeated and the last play of a stage game is unknown beforehand such settings can be modeled as infinitely repeated games with discounted payoffs additionally if the strategies in these repeated games can be represented by finite automata or computing machines we can see how the mix of strategies in the population evolves the evolutionary framework is very important here and we can think of the process as representing a situation where the most successful strategies are imitated in future play of the game maynard smith and price 1973 are among those credited with introducing evolutionary game theory and axelrod s 1984 use of evolutionary arguments to justify cooperation in his prisoners dilemma tournament is one of the most well known applications axelrod s tournament pitted strategies submitted as computer programs against one another with the most successful increasing their proportion in the population while the less effective died out a cooperative population emerged from the evolutionary process in the tournament others have studied infinite repeated prisoners dilemmas in an evolutionary framework offering a wide variety of models with results that vary similarly 1 an important contribution to the study of repeated games was the introduction of bounded rationality models allowing strategies of finite complexity to be modeled 2 the simple strategies studied here incorporate elements of these bounded rationality models they are also subject to evolutionary forces and may mutate or change to similar strategies in an intuitively appealing way the next section is devoted to motivating the study of the repeated prisoners dilemma as an important tool in economic analysis specifically a very rudimentary model of collusion between duopolists is laid out indicating how the game can be used to analyze this situation section iii reviews the essentials of evolutionary stability which were presented by maynard smith 1982 10 27 the results of computer simulations with randomly perturbed evolutionary processes are then reported these allow us to see that if the future is not very important we may find noncooperative populations but if the players care enough about the future the population may cycle between being cooperative and noncooperative finally the paper is summarized il the prisoners dilemma and economic theory the prisoners dilemma has many applications in economic theory consider for example the situation found in many economic principles texts where each of two firms simultaneously decides how much output to produce in a given period

rational behaviour in extensive form games it is argued that subgame perfect equilibrium behavior is not an inevitable consequence of common belief of rationality among players in noncooperative extensive form games the argument centers around a particular extensive form game with perfect information in the context of this game it is argued that if rationality is not common belief throughout play of the game then it can be perfectly rational to play contrary to subgame perfection even if rationality is common belief at the beginning of the game it is then shown that it is impossible for rationality to be common belief throughout every play of the game

economic restructuring gender and the allocation of time abstract a significant aspect of economic life takes place in an area of production largely ignored in standard macroeconomic analysis namely the household production of nonmarketed goods and services these household produced goods and services are vital for social reproduction and human development moreover there is a dynamic interaction between their production and that of the market economy as household members especially women must allocate their time between the two sets of economic activities section 2 provides some stylized facts about the nature and scope of nonmarket activities taking place within the household unit and how they relate to the market economy methodological issues concerning the measurement of the production of nonmarketed goods and services and of time use patterns are discussed in section 3 sections 4 and 5 examine the empirical evidence regarding the intensity of time devoted to nonmarket and market work by women and the resulting consequences on their well being as well as on the development of children there are longterm serious economic and welfare consequences of these responses that make such a topic an urgent one for both academics and policy makers alike a summary of the major points raised concludes the paper

the evolutionary stability of cooperation is cooperation without central authority stable if so how robust is it despite what might be the conventional wisdom the evolution of cooperation did not solve this problem deductively in fact results obtained later by others seem to have contradicted the book s main message reexamining this exceptionally influential work yields a new picture part of axelrod s evolutionary story turns out to be false but the main intuition that retaliatory strategies of conditional cooperation are somehow advantaged proves correct in one specific and significant sense under a standard evolutionary dynamic these strategies require the minimal frequency to stabilize hence they support the most robust evolutionary equilibrium the easiest to reach and retain moreover the less efficient a strategy the larger is its minimal stabilizing frequency hobbesian strategies of pure defection are the least robust our main theorems hold for a large class of games that pose diverse cooperation problems prisoner s dilemma chicken stag hunt and many others

a core selection for regulating a single output monopoly we consider a single output production economy in which all coalitions of agents have access to the technology under increasing returns to scale the corresponding cooperative game without side payments is convex and hence has a large core we propose a core selection that is obtained by considering the lowest price of output relative to input such that the corresponding vector of indirect utilities is feasible the constant returns equivalent allocation is feasible and achieves this utility vector it satisfied the property of technological monotonicity when the production possibility set expands no agent faces a utility loss technological monotonicity and the core property together characterize the constant returns equivalent solution

sophistication and the persistence of cooperation abstract sophistication is costly in an evolutionary framework using replicator dynamics this fact is instrumental in explaining the persistence of cooperation in joint venture situations with prisoner s dilemma characteristics without relying on any reciprocity argument moreover the asymptotically stable equilibrium is symbiotic with co existence of cooperation defection and cautious cooperation very much like what we observe in reality

in and out of equilibrium ii evolution in repeated games with discounting and complexity costs abstract we explore evolutionary dynamics for repeated games with small but positive complexity costs we begin by extending a folk theorem result by cooper 1996 to continuation probabilities or discount rates smaller than 1 then we show that all d has a uniform invasion barrier since none of the more cooperative equilibria are robust against indirect invasions we might expect not to observe any cooperative equilibria when complexity costs are positive the average level of cooperation in the dynamics however can hover anywhere between no cooperation at all and the average level of cooperation in the absence of complexity costs depending on how small complexity costs are and how large the population is

correlated equilibrium as an expression of bayesian rationality if it is common knowledge that the players in a game are bayesian utility maximizers who treat uncertainty about other players actions like any other uncertainty then the outcome is necessarily a correlated equilibrium random strategies appear as an expression of each player s uncertainty about what the others will do not as the result of willful randomization use is made of the common prior assumption according to which differences in probability assessments by different individuals are due to the different information that they have where information may be interpreted broadly to include experience upbringing and genetic makeup copyright 1987 by the econometric society

the reeded edge and the phillips curve money neutrality common knowledge and subjective beliefs abstract i present a simple two person auction model in which a seller and a buyer make bids in terms of money however the value of a unit of money is uncertain i show 1 a monetary revaluation has purely nominal effects if and only if it is common knowledge 2 if seller and buyer have identical beliefs making the value of money common knowledge maximizes total gains from trade 3 if seller and buyer are equally well informed and have identical beliefs then monetary revaluations have no net effect 4 when the seller knows the value of money but the buyer does not the expected utilities of both seller and buyer are proportional to 1 1 2 where is the standard deviation of the value of money expressed as a fraction of the mean and 5 when beliefs are subjective monetary policy can improve total gains from trade as in friedman s explanation of the phillips curve and an optimal level of inflation can be determined journal of economic literature classification numbers c78 e52

the optimality of boiteux ramsey pricing consider an economy with one public enterprise that is subject to a budgetary constraint and charges prices according to the first order necessary conditions suggested by boiteux 1956 or in another context by ramsey 1972 we state restrictive conditions sufficient to ensure that the resulting allocation is second best author s abstract

on the interpretation of the nash bargaining solution and its extension to non expected utility preferences the paper reexamines the foundations of the axiomatic nash bargaining theory more specifically it questions the interpretation of the nash bargaining solution and extends it to a family of non expected utility preferences a bargaining problem is presented as x d 2 where x is a set of feasible agreements described in physical terms d is the disagreement event and 1 and 2 are preferences defined on the space of lotteries in which the prizes are the elements in x and d the ordinal nash bargaining solution is defined as an agreement y satisfying for all p e 0 1 and for all x e x if px 1 y then py 2 x and if px 2 y then py x where px is the lottery which gives x with probability p and d with probability 1 p revisions of the pareto symmetry and iia axioms characterize the ordinal nash bargaining solution in the expected utility case this definition is equivalent to that of the nash bargaining solution however this definition is to be preferred since it allows a statement of the nash bargaining solution in everyday language and makes possible its natural extension to a wider set of preferences it also reveals the logic behind some of the more interesting results of the nash bargaining solution such as the comparative statics of risk aversion and the connection between the nash bargaining solution and strategic models

alternating offer bargaining with two sided incomplete information i study alternating offer bargaining games with two sided incomplete information about the players discount rates for both perfect bayesian equilibrium and a rationalizability style notion i characterize the set of expected payoffs which may arise in the game i also construct bounds on agreements that may be made the set of expected payoffs is easy to compute and incorporate into applied models my main result is a full characterization of the set of perfect bayesian equilibrium payoffs for games in which the distribution over the players discount rates is of wide support yet is in a weak sense close to a point mass distribution i prove a lopsided convergence result each player cannot gain from a slight chance that she is a strong type but the player can suffer greatly if there is a slight chance that she is a weak type

rationalizable strategic behavior and the problem of perfection this paper explores the fundamental problem of what can be inferred about the outcome of a noncooperative game from the rationality of the players and from the information they possess the answer is summarized in a solution concept called rationalizability strategy profiles that are rationalizable are not always nash equilibria conversely the information in an extensive form game often allows certain unreasonable nash equilibria to be excluded from the set of rationalizable profiles a stronger form of rationalizability is appropriate if players are known to be not merely rational but also cautious what constitutes rational behavior in a noncooperative strategic situation this paper explores the issue in the context of a wide class of finite noncooperative games in extensive form the traditional answer relies heavily upon the idea of nash equilibrium nash 17 the position developed here however is that as a criterion for judging a profile of strategies to be reasonable choices for players in a game the nash equilibrium property is neither necessary nor sufficient some nash equilibria are intuitively unreasonable and not all reasonable strategy profiles are nash equilibria the fact that a nash equilibrium can be intuitively unattractive is well known the equilibrium may be imperfect introduced into the literature by selten 20 the idea of imperfect equilibria has prompted game theorists to search for a narrower definition of equilibrium while this research some of which will be discussed here has been extremely instructive it remains inconclusive theorists often agree about what should happen in particular games but to capture this intuition in a general solution concept has proved to be very difficult if this paper is successful it should make some progress in that direction the other side of the coin has received less scrutiny can all non nash profiles really be excluded on logical grounds i believe not the standard justifications for considering only nash profiles are circular in nature or make gratuitous assumptions about players decision criteria or beliefs the following discussion of these points is extremely brief due to space constraints more detailed arguments may be found in pearce 18

time use work and overlapping activities evidence from australia the overlapping of activities is an important dimension of time use that has previously received little attention in economic analysis most time use studies have looked only at primary activities ignoring the fact that individuals often perform two or more activities simultaneously this seriously underestimates the time spent on several economic activities such as childcare and housework which are also performed as secondary activities using a two adult household sub sample from the 1992 national australian time use survey this paper examines the incidence and determinants of overlapping activities among 3 966 adult male and female household members it first shows that inclusion of overlapping activities in time use measurements provides a better estimation of the economic contribution of individuals especially in non market production tobit models are then estimated to examine the effects of economic social and demographic factors on the incidence of overlapped work activity the findings which are found to be robust showed that gender household life cycle and composition education cultural norms employment status and level of income earnings influence the extent to which individuals particularly women perform secondary work activities conclusions are drawn in the final section of the paper copyright 2003 oxford university press

evolution of repeated prisoner s dilemma play under logit dynamics in an evolutionary set up we append an ecology of iterated prisoner s dilemma ipd game strategies consisting of unconditional cooperators allc unconditional defectors alld and reactive players tft with two repeated strategies that have received less attention in the evolutionary ipd game literature the error proof generous tit for tat gtft which with a certain probability re establishes cooperation after a possibly by mistake defection of the opponent and the penitent stimulus response wsls strategy that resets cooperation after the opponent punished for defection an abundance of rock paper scissors like patterns is discovered in the 3x3 ecologies comprising pavlovian and generous gtft players interestingly the evolutionary success of pavlov seems to depend on the absence of unconditional allc cooperators in the ecologies investigated

economists models of learning abstract economic theorists have intensively studied learning in games and decisions over the last decade this essay puts some of the work in perspective and offers opinions about what still needs to be learned journal of economic literature classification numbers c73 d83

language meaning and games a model of communication coordination and evolution language is a powerful coordination device we generalize the cheap talk approach to pre play communication by way of introducing a meaning cor respondence between messages and actions and by postulating two axioms met by natural languages players have a lexicographic preference second to material payoffs against deviating from the meaning correspondence under two sided communication in generic and symmetric n 3 n coordination games a nash equilibrium component in such a lexicographic communication game is evolutionarily stable if and only if it results in the unique pareto efficient out come of the underlying game we extend the analysis to one sided communica tion in arbitrary finite two player games jel c72 c73 z 3

evolutionary game theory game theory has been developed as a theory of rational behavior in interpersonal conflict situations with economics and the other social sciences being the intended fields of application since the theory is based on an idealized picture of human rationality it is by no means obvious that it can be applied to situations in which the players cannot be attributed any intellectual capabilities however in their seminal paper the logic of animal conflict maynard smith and price showed that animal contests can be modeled as games and that game theory can be applied successfully in biology the objective of this chapter is to review some of the developments in this biological branch of game theory and to point out the distinctions and similarities with the classical branch also see parker and hammerstein 1985 the main emphasis will be on the mathematics involved lack of space prevents an extensive discussion of the underlying biological assumptions as well as an analysis of specific examples for these the reader is referred to the very stimulating book evolution and the theory of games by john maynard smith

conflict leads to cooperation in demand bargaining abstract we consider a multilateral nash demand game in which short sighted players come to the bargaining table with requests for both coalition partners and the potentially generated resource we prove that the resulting process converges with probability one to a state in which all players agree on a strictly self enforcing division of resources i e a strict core allocation highlighting group dynamics we show how the myopic actions of players may lead to the break up of groups in the short run but can ultimately bring about a situation from which a strictly self enforcing allocation can be reached

a simple model of collective action abstract successful collective action is usually accompanied by explicit systems for punishing noncooperators a simple model of collective action is presented in which such punishment opportunities are available and some individuals have a taste for exercising them the model suggests that many of the correlates of successful collective action in the commons management literature are endogenous and it clarifies the channels through which others operate it points to the importance of communication costs and asymmetries in power rather than wealth in explaining when collective action fails heterogeneity in the ability to inflict punishment or be hurt by it may result in collective action becoming infeasible especially when there are increasing returns in the production of the public good but there is a range of parameters in which heterogeneity is favorable to cooperation

self confirming equilibrium rium path of play thus if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs even though beliefs about play at off path information sets need not be correct we characterize the ways in which self confirming equilibria and nash equilibria can differ and provide conditions under which self con firming equilibria correspond to standard solution concepts nash equilibrium and its refinements describe a situation in which i each player s strategy is a best response to his beliefs about the play of his opponents and ii each player s beliefs about the opponents play are exactly correct we propose a new equilibrium concept self confirming equilibrium that weakens condition ii by requiring only that players beliefs are correct along the equilibrium path of play thus each player may have incorrect beliefs about how his opponents would play in contingencies that do not arise when play follows the equilibrium and moreover the beliefs of different players may be wrong in different ways the concept of self confirming equilibrium is motivated by the idea that noncooperative equilibria should be interpreted as the outcome of a learning process in which players revise their beliefs using their observations of previous play suppose that each time the game is played the players observe the actions chosen by their opponents but that players do not observe the actions their opponents would have played at the information sets that were not reached along the path of play then if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs so the equilibrium is self confirming in the weak sense of not being inconsistent with the evidence by analogy with the literature on the bandit problem e g rothschild 1974 one might expect that a non nash self confirming equilibrium can be the outcome of plausible learning processes this point was made by fudenberg and

feminization of the labor force the effects of long term development and structural adjustment abstract using crosscountry data pooled for 1985 and 1990 we analyze the relationship between women s share of the labor force and the processes of long term economic development and macroeconomic changes associated with structural adjustment we find that the relationship between long term development and women s share of the labor force is u shaped controlling for the feminization u we also find that structural adjustment policies have led to an increase in feminization of the labor force via worsening income distribution and increased openness

leave and let leave a sufficient condition to explain the evolutionary emergence of cooperation the option to leave your current partner in response to his behavior also known as conditional dissociation is a mechanism that has been shown to promote the emergence and stability of cooperation in many social interactions this mechanism nevertheless has always been studied in combination with other factors that are known to support cooperation by themselves in this paper we isolate the effect of conditional dissociation on the evolution of cooperation and show that this mechanism is enough to sustain a significant level of cooperation if the expected lifetime of individuals is sufficiently long 2014 elsevier b v all rights reserved

long term trends in the world economy the gender dimension abstract this paper considers the implications of long term trends in the international economy for the relative employment and income of men and women in developed and developing countries we find that given a persistent gender division of labor mass unemployment in the north is due to different forces operating on men and women the rate of growth of men s jobs has fallen because of deindustrialization but men have not withdrawn from the labor force at a comparable rate women have been entering the labor force in feminized jobs at a faster rate than they have been created in the south women have largely taken traditionally feminized jobs in the labor intensive export oriented growing manufacturing sectors in latin america entry has been largely in the service sector men have been losing jobs in agriculture and domestic manufacturing the paper proposes that the optimal solution to the mass unemployment problem in the north as well as in the south and the apparent competition for jobs between the north and the south and between men and women lies in achieving a trend increase in the growth rate of oecd and world aggregate demand and output but such a trend rise in the long term rate of growth of demand would only be possible if there were new cooperative institutional arrangements within and between countries in such arrangements women need to have an important independent role

decreasing serial cost sharing under economies of scale we consider the problem of cost sharing in the presence of increasing returns to scale and potential strategic behavior on the part of consumers we show that any smooth and strictly monotonic mechanism for which a nash equilibrium exists for all profiles of convex and monotonic preferences must be dictatorial however we propose a cost sharing mechanism the decreasing serial mechanism for which an interesting domain restriction ensures existence of a noncooperative equilibrium for its cost sharing game a characterization theorem of the mechanism based on the strategic properties of existence uniqueness and efficiency of its noncooperative equilibrium is provided journal of economic literature classification numbers c70 c72 d70 cost allocation is a practical problem that organizations of all kinds face universities allocate computing costs among departments aviation authorities set landing fees for aircraft based on their size regulatory com missions set rates for electricity water and other utilities based on the costs of providing these services the common feature in all of these exam ples is that prices are not determined externally by market forces but are set internally by mutual agreement or administrative decision a simple situation where a cost sharing problem can emerge is when a set of users share a technology that transforms a single input into a single output we study this cost sharing problem when the cost function is increasing and concave examples include the division of costs incurred in setting telephone lines or a water supply system the assessment of fees to pay for a secretary or a gardener s services and so on the situations we have in mind are those of cooperative production or natural nonregulated monopolies for either of these situations there is no obvious answer to the question of how to divide the cost of producing the total output among the users

buying time and saving time strategies for managing household production time buying strategies used more often by employed wife families than nonemployed wife families were purchase of child care meals away from home and disposable diapers time saving strategies used by employed wives were preparing fewer meals at home reduced time in household production and reduced time in leisure wife s employment made no difference in time spent in household production by other family members

rational expectations in games a player i s actions in a game are determined by her beliefs about other players these depend on the game s real life context not only its formal description define a game situation as a game together with such beliefs call the beliefs and i s resulting expectation rational if there is common knowledge of rationality and a common prior in two person zero sum games i s only rational expectation is the game s value in an arbitrary game g we characterize i s rational expectations in terms of the correlated equilibria of the doubled game 2g in which each of i s strategies in g appears twice

work and empowerment women and agriculture in south india this article explores the implications of women s work in agriculture in telangana a region in the state of andhra pradesh india i suggest that higher capital costs for cultivators post liberalisation increased the pressure to contain wage costs in a region where women form the majority of the agricultural wage labour force under such conditions when women perform both own cultivation as well as agricultural wage work in the fields of others they face pressure to restrict bargaining for higher wages contributing to a widening gender wage gap to the extent that wages shape intra household bargaining power the empowering effect of workforce participation for such women would thus be blunted from available nss data i provide some preliminary evidence in support of this argument

evolution and game theory introduced by john von neumann and oskar morgenstern 1944 energized by the addition of john nash s 1950 equilibrium concept and popularized by the strategic revolution of the 1980s noncooperative game theory has become a standard tool in economics in the process attention has increasingly been focused on game theory s conceptual foundations two questions have taken center stage should we expect nash equilibrium play that is should we expect the choice of each player to be a best response to the choices of the other players if so which of the multiple nash equilibria that arise in many games should we expect in the 1980s game theorists addressed these questions with models based on the assumptions that players are perfectly rational and have common knowledge of this rationality in the 1990s however emphasis has shifted away from rationalitybased to evolutionary models one reason for this shift was frustration with the limitations of rationality based models these models readily motivated one of the requirements of nash equilibrium that players choose best responses to their beliefs about others behavior but less readily provided the second requirement that these beliefs be correct simultaneously rationality based criteria for choosing among nash equilibria produced alternative equilibrium refinements strengthenings of the nash equilibrium concept designed to exclude implausible nash equilibria with sufficient abandon as to prompt despair at the thought of ever choosing one as the right concept a second reason for the shift away from rationality based game theory was a change in the underlying view of what games represent it was once typical to interpret a game as a literal description of an idealized interaction in which an assumption of perfect rationality appeared quite

merging reputation and repeated games with incomplete information we relate and unify several results that appeared in the following domains merging of probabilities perturbed games and reputation phenomena and repeated games with incomplete information journal of economic literature classification numbers c72 d83

reputation incomplete information and differences in patience in repeated games with multiple equilibria a game with multiple equilibria and incomplete information which allows for reputation building is repeated infinitely many times increasing differences in patience contribute to a greater likelihood of cooperation as one player becomes sufficiently more patient than the other player both players benefit and both players risk limits and the conflict between the players decrease

evolution in the finitely repeated prisoner s dilemma abstract this paper examines some aspects of evolutionary dynamic behavior in the finitely repeated prisoner s dilemma the fitness of cooperation found in the best known simulation of this type that by robert axelrod stems from strategy set restrictions the game used for the simulation has a continuum of pure cooperation equilibria and no pure defection equilibrium some new simulations are presented here for the finitely repeated game although cooperation is ultimately exploited and extinguished dynamic paths can pseudo converge in ways that allow partial cooperation to flourish for extended periods of time

cooperation secret handshakes and imitation in the prisoners dilemma building on a j robson 1990 j theoret biol 144 379 396 we introduce into the repeated prisoners dilemma mutants who have the ability to send a costly signal i e the secret handshake before each round of the game and to condition their actions on whether or not they observe the same signal from their opponent we show that as mutation probabilities approach zero in the limit cooperation occurs a positive fraction of the time using simulations to study the behavior of the system with nonzero mutation probabilities we obtain similar results surprisingly in some cases an increased payoff to unilateral defection actually raises the level of cooperation journal of economic literature classification numbers c70 c72 d60

games with procedurally rational players the authors study interactive situations in which players are boundedly rational each player rather than optimizing given a belief about the other players behavior as in the theory of nash equilibrium uses the following choice procedure she first associates one consequence with each of her actions by sampling literally or virtually each of her actions once then she chooses the action that has the best consequence the authors define a notion of equilibrium for such situations and study its properties copyright 1998 by american economic association

the evolution of cooperation in infinitely repeated games experimental evidence 1 for example in infinitely repeated prisoner s dilemma games with patient agents both cooperate and defect may be played in equilibrium even though the theory of infinitely repeated games has been used to explain cooperation in a variety of environments no definitive solution has been provided to the problem of equilibrium selection when both cooperation and defection are possible equilibrium outcomes which one should we expect to prevail previous experimental evidence has shown that subjects often fail to coordinate on a specific equilibrium when they play a small number of infinitely repeated games some subjects attempt to establish cooperative agreements while others defect but how would behavior evolve as subjects learn from previous repeated games would cooperation prevail when it can be supported in equilibrium or will subjects learn

bargaining with history dependent preferences abstract two impatient players bargain over a pie of size one according to the infinite alternating offers procedure players payoffs depend not only on the outcome but also on the process of the bargaining specifically they prefer impasse to any agreement that gives them lower discounted utility than would have been derived from accepting earlier offers we characterize the essentially unique subgame perfect equilibrium path which consists of gradual concessions the more patient players are the longer it takes them to reach an agreement when players become infinitely patient the efficiency loss is substantial yet the equilibrium division converges to the nash solution

testing threats in repeated games under most game theoretic solution concepts equilibrium beliefs are justified by off equilibrium events i propose an equilibrium concept for infinitely repeated games called nash equilibrium with tests newt according to which players can only justify their equilibrium beliefs with events that take place on the equilibrium path itself in newt players test every threat that rationalizes a future non myopic action that they take the tests are an integral part of equilibrium behavior characterization of equilibrium outcomes departs from the classical folk theorems the concept provides new insights into the impact of self enforcement norms such as reciprocity on long run cooperation c 2004 elsevier inc all rights reserved

how poor women earn income in sub saharan africa and what works against them abstract in sub saharan africa household based agricultural activity remains the foundation of rural livelihoods and women do most of the work their activities are under increasing stress they and their children are falling into poverty even as their need for cash income is increasing although they keep a foothold in the household economy increasingly women are dependent on self employment or wage work for survival they have little access to services and few opportunities to become more productive their situation is exacerbated by continuing male dominance and unequal household responsibilities the informal sector offers opportunities for entrepreneurship especially in trading or small scale agroindustry but unlicensed activity is discouraged in many countries some women also find themselves competing with businesses that are run or licensed by the state several micro level interventions are identified that support women s income earning activities and may halt further deterioration in rural livelihoods

coping and resilience during the food fuel and financial crises how and how well have people with low incomes been coping with global economic volatility since 2008 this question is addressed through a synthesis of qualitative research in 17 countries on how selected groups of people coped with the local effects of the global food fuel and financial crises from 2008 2011 the data are a uniquely large body of qualitative evidence that afford insights into how people affected by a common global economic shock coped as it transmitted to their diverse social and economic contexts the paper describes and categorizes the impacts of coping responses used analyzing the distribution of the costs of coping the effects on social and gender relations and the sources of support including public policy non state support and informal social support the paper is organized as follows section one gives introduction section two sets out conceptual approaches to analyzing crisis coping section three describes the approach setting out the methodological advantages and limitations section four describes and categorizes the impacts and coping responses section five analyzes sources and types of support identified by the research section six draws concludes