eductive stability in real business cycle models we reexamine issues of coordination in the standard rbc model is the unique rational expectations equilibrium attainable by rational agents who contemplate the possibility of small deviations from equilibrium surprisingly we nd that coordination cannot be expected even with strong common knowledge assumptions rational agents anticipating small but persistent deviations are led to take actions that eventually contradict the common knowledge assumption this impossibility theorem for eductive learning is not fully overcome when adaptive learning is incorporated into the framework

competition for advertisers and for viewers in media markets standard models of advertising financed media assume consumers patronise a single media platform precluding effective competition for advertisers such competition ensues if consumers multi home the principle of incremental pricing implies that multi homing consumers are less valuable to platforms then entry of new platforms decreases advertisement prices while a merger increases them and advertisement financed platforms may suffer if a public broadcaster carries advertisements platforms may bias content against multi homing consumers especially if consumers highly value overlapping content and or second impressions have low value

limited rationality and strategic interaction the impact of the strategic environment on nominal inertia much evidence suggests that people are heterogeneous with regard to their abilities to make rational forward looking decisions this raises the question as to when the rational types are decisive for aggregate outcomes and when the boundedly rational types shape aggregate results we examine this question in the context of a long standing and important economic problem the adjustment of nominal prices after an anticipated monetary shock our experiments suggest that two types of bounded rationality money illusion and anchoring are important behavioral forces behind nominal inertia however depending on the strategic environment bounded rationality has vastly different effects on aggregate price adjustment if agents actions are strategic substitutes adjustment to the new equilibrium is extremely quick whereas under strategic complementarity adjustment is both very slow and associated with relatively large real effects this adjustment difference is driven by price expectations which are very flexible and forward looking under substitutability but adaptive and sticky under complementarity moreover subjects expectations are also considerably more rational under substitutability

monetary and fiscal policy design at the zero lower bound evidence from the lab the global economic crisis of 2007 8 pushed many advanced economies into a liquidity trap a macroeconomic scenario characterised by nomial rates at the zero lower bound zlb low inflation and output below trend we design an experiment to generate empirical evidence on the effectiveness of policies aimed at managing expectations against liquidity traps in a controlled laboratory environment where expectations are elicied directly from human subjects our results suggest that monetary policy alone is not sufficient to insulate the economy form the risk of falling into a liquidity trap even if it preventively cuts the policy augmented with a fiscal switching rule succeeds in avoiding and escapiing liquidity trap episodes we also measure larger than unity fiscal mulipliers when monetary policy is constrained by the zlb experimental results in different treatments are well explained by adaptive learning

social discounting and incentive compatible fiscal policy abstract this paper considers a representative agent model of linear capital and labor income taxation in which the government cannot commit ex ante to a sequence of policies for the future in this setup if the government is more impatient than the households the capital income tax will be positive in steady state thus impatience and lack of commitment are able to generate positive capital taxes in the long run although each of these characteristics individually was not furthermore the steady state to which the economy converges is independent of initial conditions

it is not just confusion strategic uncertainty in an experimental asset market to what extent is the observed mispricing in experimental asset markets caused by strategic uncertainty and by confusion we address this question by comparing subjects initial price forecasts in two market environments one with six human traders and the other with one human and five computer traders we find that both strategic uncertainty and confusion contribute equally to the median initial forecast deviation from the fundamental value the effect of strategic uncertainty is greater for subjects with a perfect score in the cognitive reflection test and it is not significant for those with low scores

optimal taxes without commitment abstract in the problem of optimal taxation in an economy with labor and capital the optimal solution when the government can commit to a sequence of tax rates entails that the tax on capital tends to zero in the limit with all the tax burden on labor it is well known however that this solution is time inconsistent so if the commitment power is not perfect this second best tax plan will not be sustainable we model explicitly the trade off between the cost of revising the tax plan and the benefit of the revision as a result when commitment is not possible both the limit tax rate and the steady state capital are different from their levels in the second best solution limit taxes on capital may be strictly positive but it may also be the case that the only sustainable plan has subsidies to capital the subsidies induce an overaccumulation of capital which becomes a commitment device against revisions of the tax plan journal of economic literature classification numbers h21 c73

bad investments and missed opportunities postwar capital flows to asia and latin america since 1950 the economies of east asia grew rapidly but received little inter national capital while latin america received considerable international capitaleven as their economies stagnated the literature typically explains the failureof capital to flow to high growth regions as resulting from international capitalmarket imperfections this paper proposes a broader thesis that country specificdistortions such as domestic labor and capital market distortions also impactcapital flows we develop a dsge model of asia latin america and the rest ofthe world that features an open economy business cycle accounting framework tomeasure these domestic and international distortions and to quantify their con tributions to international capital flows we find that domestic distortions havebeen the predominant drivers of international capital flows and that the generalequilibrium effects of these distortions are very large international capital market distortions also matter but less

guessing with negative feedback an experiment we investigate experimentally a new variant of the beauty contest game bcg in which players actions are strategic substitutes a negative feedback bcg our results show that chosen numbers are closer to the rational expectation equilibrium than in a strategic complements environment a positive feedback bcg we also find that the estimated average depth of reasoning from the cognitive hierarchy model does not differ between the two environments we show that the difference may be attributed to the fact that additional information is more valuable when players actions are strategic substitutes rather than strategic complements in line with other recent experimental findings

adaptive versus eductive learning theory and evidence adaptive and eductive learning are two widely used ways of modeling the process by which agents learn a rational expectation equilibrium ree in this paper we report an experiment where we exploit differences in the conditions under which adaptive and eductive learning converge to ree so as to investigate which approach provides the better description of the learning behavior of human subjects our results suggest that the path by which the system converges appears to be a mixture of both adaptive and eductive learning model predictions

expectation calculation and macroeconomic dynamics the authors establish a framework wherein agents make expectation revision decisions subject to a specified calculation technology and preferences over forecast errors the technology endows agents with correctly specified economic models but the cost of expectation calculation using these models leads to gradual and incomplete adjustment to long run rational expectation equilibrium the rational expectations hypothesis emerges as a special case of the equilibrium paths obtained in the authors framework in a natural rate model of monetary policy calculation technology gives rise to long run nonneutrality and hysteresis effects and incomplete adjustment of forecast rules causes output fluctuations to be amplified copyright 1992 by american economic association

redistributive taxation in a simple perfect foresight model abstract we investigate the redistributive potential of capital taxation in an intertemporal maximizing model of capital formation first even unanticipated redistributive capital taxation is severely limited in its effectiveness since it depresses wages second under any convergent redistributive tax policy which maximizes a paretian social objective the capital income tax will converge to zero independent of the factor supply elasticities these results are independent of workers holdings of capital

optimal taxation without state contingent debt in an economy studied by lucas and stokey tax rates inherit the serial correlation structure of government expenditures belying barro s earlier result that taxes should be a random walk for any stochastic process of government expenditures to recover a version of barro s random walk tax smoothing outcome we modify lucas and stokey s economy to permit only risk free debt having only risk free debt confronts the ramsey planner with additional constraints on equilibrium allocations beyond one imposed by lucas and stokey s assumption of complete markets the ramsey outcome blends features of barro s model with lucas and stokey s in our model the contemporaneous effects of exogenous government expenditures on the government deficit and taxes resemble those in lucas and stokey s model but incomplete markets put a near unit root component into government debt and taxes an outcome like barro s however we show that without ad hoc limits on the government s asset holdings outcomes can diverge in importa

eductive learning and the rationalizability of oligopoly games abstract this paper extends the eductive learning approach in settings with non atomistic agents it shows the connection between the characterization of rationalizable sets by basu 1991 and the seminal result by guesnerie 1992 in the context of cournot oligopoly models

an illustration of the essential difference between individual and social learning and its consequences for computational analyses abstract drawing a conclusion from recent insights in evolutionary game theory we show that a so called spite effect implies that there is an essential difference between individual and social learning we illustrate its consequences for the choice of computational tools in economics and social settings in general by analyzing two variants of a genetic algorithm

rationalizable strategic behavior the notion of equilibrium proposed by nash 19 has come to play a dominant role in economic applications of noncooperative games while analyses of nash equilibria have unquestionably contributed to our understanding of economic behavior it would be unreasonably optimistic to maintain that nash solved the problem of noncooperative strategic choice there is a small literature beginning with ellsberg 6 and a much larger oral tradition which argues that nash behavior is neither a necessary consequence of rationality nor a reasonable empirical proposition in this paper i take the view that although there may be various reasons why an agent might select a nash strategy the notion of an equilibrium has little intrinsic appeal within a strategic context when an agent reaches a decision in ignorance of the strategies adopted by other players rationality consists of making a choice which is justifiable by an internally consistent system of beliefs rather than one which is optimal post hoc this point of view is not original indeed most serious justifications of the nash hypothesis embrace such an approach arguing that agents will expect the game to yield a nash outcome and consequently will choose their equilibrium strategies nevertheless when we think in terms of maximizing utility subject to expectations rather than realizations it becomes clear that the nash hypothesis far from being a consequence of rationality arises from certain restrictions on agents expectations which may or may not be plausible depending upon the game being played we are then quite naturally led to ask are there any restrictions of individuals expectations and hence choices which are required by rationality alone rather than by subjective plausibility this paper is concerned with defining justifying characterizing and refining a criterion for rational strategic choice which i label rationalizability

political economy of debt and growth abstract a theory of endogenous fiscal policy and growth is developed fiscal policy debt income tax spending on local public goods and public investment is determined through legislative bargaining economic growth depends directly on public investment private investment in human capital and via learning by doing labor supply the model economy converges to a balanced growth path during the transition to the balanced growth path public debt grows faster than gdp provisions of public goods and infrastructure grow slower than gdp and the tax rate declines the model is used to assess welfare implications of austerity programs

expectations and bubbles in asset pricing experiments abstract we present results on expectation formation in a controlled experimental environment in each period subjects are asked to predict the next price of a risky asset the realized market price is derived from an unknown market equilibrium equation with feedback from individual forecasts in most experiments prices deviate from the benchmark fundamental and bubbles emerge endogenously these bubbles are inconsistent with rational expectations and seem to be driven by trend chasing behavior or positive feedback expectations of the participants we also analyze individual predictions of participants and find that participants within a group tend to coordinate on a common prediction strategy

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

optimal fiscal and monetary policy in an economy without capital abstract this paper is concerned with the structure and time consistency of optimal fiscal and monetary policy in an economy without capital in a dynamic context optimal taxation means distributing tax distortions over time in a welfare maximizing way for a barter economy our main finding is that with debt commitments of sufficiently rich maturity structure an optimal policy if one exists is time consistent in a monetary economy the idea of optimal taxation must be broadened to include an inflation tax and we find that time consistency does not carry over an optimal inflation tax requires commitment by rules in a sense that has no counterpart in the dynamic theory of ordinary excise taxes the reason time consistency fails in a monetary economy is that nominal assets should from a welfare maximizing point of view always be taxed away via an immediate inflation in a kind of capital levy this emerges as a new possibility when money is introduced into an economy without capital

opportunity and social mobility the fact that the children of rich parents have better economic prospects than the children of poor parents unequal opportunity is generally thought to be one of the weak points of modem capitalist societies the ability of the descendants of poor families to eventually become rich and the descendants of rich families to eventually become poor social mobility is commonly considered to be one of the strong points of these societies here i argue that both of these characteristics are in fact necessary implications of an efficient societal arrangement when incentives to work hard must be provided i argue this point using a generational version of the model of phelan and townsend 1991 an infinitely repeated general equilibrium economy with incentive constraints in my model each household s stochastic output is a function of its level of effort since effort is assumed to be costly and privately observed households can shirk higher than minimal effort levels must be induced by making a household s present or future consumption dependent on the household s observed output history a large literature considers models similar to this including green 1987 atkeson and lucas 1992 phelan 1994 1995 wang 1995 hopenhayn and nicolini 1997 khan and ravikumar 2002 the main difference between the economies in that literature and here is that here instead of a household consisting of a single infinitely lived individual a household consists of a sequence of altruistically linked individuals a familial dynasty each of whom lives for one period this difference affects the appropriate societal ranking of allocations when households consist of a single infinitely lived individual allocations can be ranked according to their implied distributions of ex ante lifetime utilities if one allocation delivers a distribution of ex ante utilities dominated by another allocation then the first allocation is inefficient however if a household consists of a sequence of altruistically linked individuals then the appropriate ranking of allocations is no longer obvious how those in the first generation rank allocations will in general differ from how their descendants rank allocations this paper addresses this conflict between generations by ranking allocations according to a rawlsian veil of ignorance criterion rawls 1971 that is here society seeks to maximize the expected dynastic utility utility including altruism toward descendants of an individual who does not know into which generation he will be born and the identity or output levels of his ancestors 1 i argue that this corresponds to a societal ranking which does

what goes up must come down experimental evidence on intuitive forecasting do laboratory subjects correctly perceive the dynamics of a mean reverting time series in our experiment subjects re ceive historical data and make forecasts at dif ferent horizons the time series process that we use features short run momentum and long run partial mean reversion half of the subjects see a version of this process in which the momentum and partial mean reversion un fold over 10 periods fast while the other subjects see a version with dynamics that un fold over 50 periods slow typical subjects recognize most of the mean reversion of the fast process and none of the mean reversion of the slow process

an exploration of the eductive justifications of the rational expectations hypothesis this paper examines justifications of the rational expectations hypothesis that rely on the analysis of the agents mental forecasting educing activity which involves forecasting the forecasts of others etc the corresponding concept of eductive learning stability based on the game theoretical concept of rationalizability is primarily used within the classical muth model conditions for coordination of beliefs are interpreted and discussed they are robust to the introduction of noise more generally eductive stability fits economic intuition on coordination stability increases when the industry product differentiation increases and when decisions are sequential and observable copyright 1992 by american economic association

positive long run capital taxation chamley judd revisited according to the chamley judd result capital should not be taxed in the long run in this paper we overturn this conclusion showing that it does not follow from the very models used to derive it for the main model in judd 1985 we prove that the long run tax on capital is positive and significant whenever the intertemporal elasticity of substitution is below one for higher elasticities the tax converges to zero but may do so at a slow rate after centuries of high tax rates the main model in chamley 1986 imposes an upper bound on capital taxes we provide conditions under which these constraints bind forever implying positive long run taxes when this is not the case the long run tax may be zero however if preferences are recursive and discounting is locally nonconstant e g not additively separable over time a zero long run capital tax limit must be accompanied by zero private wealth zero tax base or by zero labor taxes first best finally we explain why the equivalence of a positive capital tax with ever increasing consumption taxes does not provide a firm rationale against capital taxation

growth in the shadow of expropriation we propose a tractable variant of the open economy neoclassical growth model that emphasizes political economy and contracting frictions the political economy frictions involve a preference for immediate spending while the contracting friction is a lack of commitment regarding foreign debt and expropriation we show that the political economy frictions slow an economy s convergence to the steady state due to the endogenous evolution of capital taxation the model rationalizes why openness has different implications for growth depending on the political environment why institutions such as the treatment of capital income evolve over time why governments in countries that grow rapidly accumulate net foreign assets rather than liabilities and why foreign aid may not affect growth

fiscal policy in debt constrained economies abstract we study optimal fiscal policy in a small open economy soe with sovereign and private default risk and limited commitment to tax plans the soe s government uses linear taxation to fund exogenous expenditures and uses public debt to inter temporally allocate tax distortions we characterize a class of environments in which the tax on labor goes to zero in the long run while the tax on capital income may be non zero reversing the standard prediction of the ramsey tax literature the zero labor tax is an optimal long run outcome if the economy is subject to sovereign debt constraints and the domestic households are impatient relative to the international interest rate the front loading of tax distortions allows the economy to build a large aggregate debt position in the presence of limited commitment we show that a similar result holds in a closed economy with imperfect inter generational altruism providing a link with the closed economy literature that has explored disagreement between the government and its citizens regarding inter temporal tradeoffs

a dynamic theory of public spending taxation and debt this paper presents a dynamic political economy theory of public spending taxation and debt policy choices are made by a legislature consisting of representatives elected by geographically defined districts the legislature can raise revenues via a distortionary income tax and by borrowing these revenues can be used tofinance a national public good and district specific transfers interpreted as pork barrel spending the value of the public good is stochastic reflecting shocks such as wars or natural disasters in equilibrium policy making cycles between two distinct regimes business as usual in which legislators bargain over the allocation of pork and responsible policy making in which policies maximize the collective good transitions between the two regimes are brought about by shocks in the value of the public good in the long run equilibrium tax rates are too high and too volatile public good provision is too low and debt levels are too high in some environments a balanced budget requirement can improve citizen welfare

public debt and optimal taxes without commitment abstract benhabib and rustichini optimal taxes without commitment j econ theory 77 1997 231 259 study the properties of optimal capital taxes in economies without commitment and no government debt they find that capital taxes may be different from zero at steady state this note shows that once governments have the possibility of issuing debt and smoothing taxes over time optimal steady state capital taxes turn out to be zero

on the optimal taxation of capital income abstract we show that in models in which labor services are supplied jointly with human capital the chamley and judd result on zero capital income taxation in the limit extends to labor taxes as long as accumulation technologies are constant returns to scale moreover for a class of widely used preferences consumption taxes are zero in the limit as well however we show by the construction of two examples that these results no longer hold for certains types of restrictions on tax rates or if there are profits generated journal of economic literatureclassification numbers e62 h21

does eductive stability imply evolutionary stability this note presents a simple example of a model in which the unique rational expectations re steady state equilibrium is eductively stable in the sense of guesnerie 2002 but where evolutionary learning as introduced in brock and hommes 1997 does not necessarily converge to the re steady state price the example is a muthian cobweb model where producers have heterogeneous expectations and select forecasting strategies based upon recent realized profits by means of a simple three types example we show that a locally stable re fundamental steady state may co exists with a locally stable two cycle we also study the muthian model with a large number of different producer types and investigate conditions under which an evolutionary adaptive learning process based upon recent realized profits enforces global convergence to the stable re steady state and when persistent periodic price fluctuations can arise

individual expectations limited rationality and aggregate outcomes recent studies suggest that the type of strategic environment or expectation feedback can have a large impact on whether the market can learn the rational fundamental price we present an experiment where the fundamental price experiences large unexpected shocks markets with negative expectation feedback strategic substitutes quickly converge to the new fundamental while markets with positive expectation feedback strategic complements do not converge but show underreaction in the short run and overreaction in the long run a simple evolutionary selection model of individual learning explains these differences in aggregate outcomes

indeterminacy of equilibria in a hyperinflationary world experimental evidence the authors design and study an olg experimental economy where the government finances a fixed real deficit through seigniorage the economy has continua of nonstationary rational expectations equilibria and two stationary rational expectations equilibria the authors do not observe nonstationary rational expectations paths observed paths tend to converge close to or somewhat below the low inflation stationary state the adaptive learning hypothesis is consistent with the data in selecting the low inflation stationary state rational expectations equilibrium as a long run stationary equilibrium nevertheless simple adaptive learning models do not capture the market uncertainty or the biases observed in the data copyright 1993 by the econometric society

optimal taxation of capital income in general equilibrium with infinite lives this paper analyzes the optimal tax on capital income in general equilibrium models of the second best agents have infinite lives and utility functions which are extensions from the koopmans form the population is heterogeneous the important property of the models is the equality between the social and the private discount rates in the long run i find that the optimal tax rate is zero in the long run for a special case of additively separable utility functions i then determine the tax rates along the dynamic path and conditions that are sufficient for the local stability of the steady state

inequality and social discounting we explore steady state inequality in an intergenerational model with altruistically linked individuals who experience privately observed taste shocks when the welfare function depends only on the initial generation efficiency requires immiseration inequality grows without bound and everyone s consumption converges to zero we study other efficient allocations in which the welfare function values future generations directly placing a positive but vanishing weight on their welfare the social discount factor is then higher than the private one and for any such difference we find that consumption exhibits mean reversion and that a steady state cross sectional distribution for consumption and welfare exists with no one trapped at misery

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

learning forecasting and optimizing an experimental study rational expectations re models have two crucial dimensions i agents on average correctly forecast future prices given all available information and ii given expectations agents solve optimization problems and these solutions in turn determine actual price realizations experimental tests of such models typically focus on only one of these two dimensions in this paper we consider both forecasting and optimization decisions in an experimental cobweb economy we report results from four main experimental treatments 1 subjects form forecasts only 2 subjects determine quantity only solve an optimization problem 3 they do both and 4 they are paired in teams and one member is assigned the forecasting role while the other is assigned the optimization task all treatments converge to rational expectation equilibrium ree but at different speeds we observe that performance is the best in treatment 1 and the worst in treatment 3 we further find that most subjects use adaptive rules to forecast prices given a price forecast subjects are less likely to make conditionally optimal production decisions in treatment 3 where the forecast is made by themselves than in treatment 4 where the forecast is made by the other member of their team which suggests that two heads are better than one in term of the speed of finding the ree

political economy of ramsey taxation abstract we study the dynamic taxation of capital and labor in the ramsey model under the assumption that taxes and public good provision are decided by a self interested politician who cannot commit to policies we show that as long as the politician is as patient as the citizens the chamley judd result of zero long run taxes holds in contrast if the politician is less patient than the citizens the best subgame perfect equilibrium from the viewpoint of the citizens involves long run capital taxation

political economy of mechanisms we study the optimal mirrlees taxation problem in a dynamic economy in contrast to the standard approach where the taxation mechanism is operated by a benevolent planner with full commitment power we focus on economies in which policy decisions are made by self interested politicians who cannot commit to policies the society controls politicians using elections we show that the provision of incentives to politicians can be partly separated from redistribution across agents and that political economy constraints can be modeled as introducing additional aggregate distortions in the dynamic mirrlees problem we provide conditions under which the political economy distortions persist or disappear in the long run if the politicians are as patient as the agents the best sustainable mechanism leads to an asymptotic allocation where the aggregate distortions arising from political economy disappear in contrast when politicians are less patient than the citizens positive aggregate labor and capital taxes remain even asymptotically we conclude by providing a brief comparison of centralized