stabilizing non fundamental asset price movements under discretion and limited information abstract inflation output and interest rate stabilization are all potential central bank objectives we explore whether monetary policy should respond to asset price fluctuations when they are driven by irrational expectational shocks to the future returns to capital in our model an optimistic shock to future returns generates both an increase in equity prices and physical investment the increased investment is inefficient and thus a central bank optimally responds to this expectations shocks this induces a trade off between stabilizing nominal prices and non fundamental asset price movements we compare the optimal policy under different assumptions full versus limited information and commitment versus discretion if the central bank has limited information about whether an asset price movement has a fundamental or non fundamental origin then the central bank responds less aggressively to the non fundamental exuberance shocks than under full information without commitment a central bank responds more aggressively to non fundamental exuberance shocks

higher order expectations in asset pricing we examine formally keynes idea that higher order beliefs can drive a wedge between an asset price and its fundamental value based on expected future payoffs we call this the higher order wedge which depends on the difference between higher and first order expectations of future payoffs we analyze the determinants of this wedge and its impact on the equilibrium price in the context of a dynamic noisy rational expectations model we show that the wedge reduces asset price volatility and disconnects the price from the present value of future payoffs the impact of the higher order wedge on the equilibrium price can be quantitatively large

the effects of surprise and anticipated technology changes on international relative prices and trade abstract this paper argues that it is important to distinguish surprise and anticipated components of total factor productivity tfp when we study the international transmission of tfp shocks we document that surprise and anticipated shocks to us tfp induce distinct dynamics for international relative prices the real exchange rate and the terms of trade and international trade real exports real imports and the trade balance our empirical findings can reconcile some conflicting empirical results in the literature and hence lead to a better understanding of the international transmission of tfp shocks in addition we evaluate a standard international macroeconomic model and discuss the mechanisms that may help to replicate our empirical findings

learning from private and public observations of othersʼ actions we study how a continuum of agents learn about disseminated information by observing others actions every period each agent observes a public and private noisy signal centered around the aggregate action taken by the population the public signal represents an endogenous aggregate variable such as a price or a quantity the private signal represents the information gathered through private communication and local interactions we identify conditions such that the average learning curve is s shaped learning is slow initially intensifies rapidly and finally converges slowly to the truth we show that increasing public information always slows down learning in the long run and under some conditions reduces welfare lastly optimal diffusion of information requires that agents strive to be different agents need to be rewarded for choosing actions away from the population average

knowing what others know coordination motives in information acquisition we explore how optimal information choices change the predictions of strategic models when a large number of agents play a game with strategic complementarity information choices exhibit complementarity as well if an agent wants to do what others do they want to know what others know this makes heterogeneous beliefs di cult to sustain and may generate multiple equilibria in models with substitutability agents prefer to difierentiate their information choices we use these theoretical results to examine the role of information choice in recent price setting models and to propose modeling techniques that ensure equilibrium uniqueness

the option value of renewable energy the case of climate change decision makers receive mixed signals from the investment literature on when it is appropriate to develop renewable energy technology substitutes for fossil fuels this question is becoming more important as attention has become focused on climate change with the assumptions that information is revealed as time passes and the new technologies take a long time to develop renewable energy alternatives are more attractive than they appear on the basis of the net present value criterion that ignores option value option value represents the value of flexibility to use or discard new technologies

optimal monetary policy and transparency under informational frictions this paper examines the optimal monetary policy and central bank transparency in an economy where firms set prices under informational frictions the economy is subject to two types of shocks determining the efficient output level and firms desired markups to minimize the welfare reducing output gap and price dispersion between firms the central bank controls firms incentives and expectations by using a monetary instrument and disclosing information on the realized shocks this paper shows that an optimal policy comprises the disclosure of a linear combination of the two shocks and the adjustment of monetary instruments contingent on the disclosed information

new directions for stochastic open economy models the paper develops a simple stochastic new open economy macroeconomic model based on sticky nominal wages explicit solution of the wage setting problem under uncertainty allows one to analyze the effects of the monetary regime on welfare expected output and the expected terms of trade despite the potential interplay between imperfections due to sticky wages and monopoly the optimal monetary policy rule has a closed form solution to motivate our model we show that observed correlations between terms of trade and exchange rates are more consistent with our traditional assumptions about nominal rigidities than with a popular alternative based on local currency pricing 2000 elsevier science b v all rights reserved

monetary policy and price responsiveness to aggregate shocks under rational inattention this paper presents a general equilibrium model that is consistent with recent empirical evidence showing that the u s price level and inflation are much more responsive to aggregate technology shocks than to monetary policy shocks the model of this paper builds on recent work by mackowiak and wiederholt 2009 who show that models of endogenous attention allocation deliver prices to be more responsive to more volatile shocks as everything else being equal firms pay relatively more attention to more volatile shocks in fact according to the u s data aggregate technology shocks are more volatile than monetary policy shocks inducing in this paper firms to pay more attention to the former than to the latter however most important this work adds to the literature by showing that the ability of the model of this paper to account for observed price dynamics crucially depends on monetary policy in particular this paper shows how interest rate feedback rules affect the incentives faced by firms in allocating attention a policy rate responding more actively to expected inflation and output fluctuations induces firms to pay relatively more attention to more volatile shocks this new mechanism of transmission of monetary policy helps rationalizing the observed behavior of prices in response to technology and monetary policy shocks and implies novel predictions about the impact of changes in taylor rules coefficients on economic fluctuations

modelling and forecasting the demand for coal in china in contrast with developed countries coal is the major energy source of china in view of its importance this paper attempts to analyse and forecast the country s demand for coal as it moves towards the next century to do this we have applied three different methods to contrast their performances in fitting the chinese data engle granger s error correction model hendry s error correction model and hendry s general to specific approach it is found that the engle granger approach outperforms the other two in terms of having the smallest ex post forecast errors using the engle granger approach the model predicts that the chinese economy will experience a 5 shortage in the year 2000

policy with dispersed information information regarding economic fundamentals is widely dispersed in society is only imperfectly aggregated through prices or other indicators of aggregate activity and cannot be centralized by the government or any other institution in this paper we seek to identify policies that can improve the decentralized use of such dispersed information without requiring the government to observe this information we show that this can be achieved by appropriately designing the contingency of taxation on ex post public information regarding the realized fundamentals and aggregate activity when information is common as in the ramsey literature or when agents have private information only about idiosyncratic shocks as in the mirrlees literature the contingency on fundamentals alone suffices for efficiency when instead agents have private information about aggregate shocks the contingency on aggregate activity is crucial an appropriate combination of the two contingencies permits the government to i dampen the impact of noise and hence reduce non fundamental volatility without also dampening the impact of fundamentals ii induce agents to internalize informational externalities and hence improve the speed of social learning iii restore a certain form of constrained efficiency in the decentralized use of information and iv guarantee that welfare increases with the provision of any additional information jel c72 d62 d82

indicator variables for optimal policy the optimal weights on indicators in models with partial information about the state of the economy and forward looking variables are derived and interpreted both for equilibria under discretion and under commitment an example of optimal monetary policy with a partially observable potential output and a forward looking indicator is examined the optimal response to the optimal estimate of potential output displays certainty equivalence whereas the optimal response to the imperfect observation of output depends on the noise in this observation

an informational rationale for action over disclosure abstract the past two decades have seen a considerable increase in the amount of public information provided by policymakers are such disclosures desirable or is it instead preferable to use such information to condition a policy instrument such a tax or an interest rate this paper studies the relative merits of each means to use a policymaker s information in a flexible class of economies that feature dispersed information and payoff and learning externalities i provide conditions for when the exclusive use of a policy instrument or disclosure is optimal i then relate these to differences in the equilibrium and socially optimal use of information i conclude with a series of applications that show how my results apply to common beauty contest models competitive economies and a broad class of macroeconomic models among others

when can changes in expectations cause business cycle fluctuations in neo classical settings abstract it is often argued that changes in expectation are an important driving force of the business cycle however it is well known that changes in expectations cannot generate positive co movement between consumption investment and employment in the most standard neo classical business cycle models this gives rise to the question of whether changes in expectation can cause business cycle fluctuations in any neo classical setting or whether such a phenomenon is inherently related to market imperfections this paper offers a systematic exploration of this issue our finding is that expectation driven business cycle fluctuations can arise in neo classical models when one allows for a sufficiently rich description of the production technology however such a structure is rarely allowed or explored in macro models in particular we identify a multi sector setting and a setting with a costly distribution system in which expectation driven business cycles can arise

insurance and opportunities a welfare analysis of labor market risk abstract using a model with constant relative risk aversion preferences endogenous labor supply and partial insurance against idiosyncratic wage risk this paper provides an analytical characterization of three welfare effects a the welfare effect of a rise in wage dispersion b the welfare gain from completing markets and c the welfare effect from eliminating risk the analysis reveals an important trade off for these welfare calculations on the one hand higher wage uncertainty increases the cost associated with missing insurance markets on the other hand greater wage dispersion presents opportunities to raise aggregate productivity by concentrating market work among more productive workers welfare effects can be expressed in terms of the underlying parameters defining preferences and wage risk or alternatively in terms of changes in observable second moments of the joint distribution over individual wages consumption and hours

limited information capacity as a source of inertia abstract we derive optimal time dependent adjustment rules from shannon s 1948 information theory in a continuous time lq prediction problem with a costly rate of information acquisition processing the optimal prediction evolves smoothly but jumps at an optimally chosen frequency when fresh information accrues a more volatile and persistent target raises the information rate required to maintain a sampling frequency this cost effect moderates and may even reverse the benefit effect on the value of information so optimal inertia is unresponsive to and nonmonotonic in the predictability of the environment conventional models with a fixed cost per observation imply no such cost effect so inertia rises quickly in the predictability of the environment

indicator variables for optimal policy under asymmetric information the optimal weights on indicators in models with partial information about the state of the economy and forward looking variables are derived and interpreted both for equilibria under discretion and under commitment the private sector is assumed to have more information about the state of the economy than the policymaker certainty equivalence holds for the optimal reaction function in state space form t he coefficients are independent of the degree of uncertainty about the state of the economy however in the case of commitment certainty equivalence does not hold for the reaction function in integrative form the policy instrument cannot be written as a distributed lag of past estimates of past states of the economy instead optimal policy will generally depend on new estimates of past states of the economy and in ways that depend on the information structure furthermore the usual separation principle does not hold since the estimation of the state of the economy is not independent of optimization and is in general quite complex we present a general characterization of optimal filtering and control in settings of this kind and discuss an application of our methods to the problem of the optimal use of real time macroeconomic data in the conduct of monetary policy

should central banks respond to movements in asset prices in recent decades asset booms and busts have been important factors in macroeconomic fluctuations in both industrial and developing countries in light of this experience how if at all should central bankers respond to asset price volatility we have addressed this issue in previous work bernanke and gertler 1999 the context of our earlier study was the relatively new but increasingly popular monetary policy framework known as inflation targeting see e g bernanke and frederic mishkin 1997 in an inflation targeting framework publicly announced medium term inflation targets provide a nominal anchor for monetary policy while allowing the central bank some flexibility to help stabilize the real economy in the short run the inflation targeting approach gives a specific answer to the question of how central bankers should respond to asset prices changes in asset prices should affect monetary policy only to the extent that they affect the central bank s forecast of inflation to a first approximation once the predictive content of asset prices for inflation has been accounted for there should be no additional response of monetary policy to assetprice fluctuations in use now for about a decade inflationtargeting has generally performed well in practice however so far this approach has not often been stress tested by large swings in asset prices our earlier research employed simulations of a small calibrated macroeconomic model to examine how an inflation targeting policy defined as one in which the central bank s instrument interest rate responds primarily to changes in expected inflation might fare in the face of a boom and bust cycle in asset prices we found that an aggressive inflationtargeting policy rule in our simulations one in which the coefficient relating the instrument interest rate to expected inflation is 2 0 substantially stabilizes both output and inflation in scenarios in which a bubble in stock prices develops and then collapses as well as in scenarios in which technology shocks drive stock prices intuitively inflation targeting central banks automatically accommodate productivity gains that lift stock prices while offsetting purely speculative increases or decreases in stock values whose primary effects are through aggregate demand conditional on a strong policy response to expected inflation we found little if any additional gains from allowing an independent response of central bank policy to the level of asset prices in our view there are good reasons outside of our formal model to worry about attempts by central banks to influence asset prices including the fact that as history has shown the effects of such attempts on market psychology are dangerously unpredictable hence we concluded that inflationtargeting central banks need not respond to asset prices except insofar as they affect the inflation forecast in the spirit of recent work on robust control the exercises in our earlier paper analyzed the performance of policy rules in worst case discussants robert shiller yale university glenn rudebusch federal reserve bank of san francisco kenneth rogoff harvard university

optimal monetary policy with imperfect common knowledge we study optimal nominal demand policy in a flexible price economy with monopolistic competition where firms have imperfect common knowledge about the shocks hitting the economy information imperfections emerge endogenously because firms are assumed to have finite shannon capacity to process information we then ask how policy that minimizes a quadratic objective in output and prices depends on firms processing capacity when price setting decisions of firms are strategic complements we find that policy should nominally accommodate white noise mark up shocks for a large range of capacity values this fi nding is robust to the policy maker observing shocks imperfectly or being uncertain about firms processing capacity when mark up shocks are persistent accommodation may even have to increase in the medium term but has to decrease in the long run thereby generating a hump shaped price response and a slow reduction in output instead when prices are strategic substitutes policy tends to react with nominal demand contractions to mark up shocks in addition there might exist discontinuities between common knowledge equilibria and equilibria with small amounts of imperfect common knowledge

communication and monetary policy recent trends toward greater central bank independence and the adoption of formal inflation targeting by several countries have served to emphasize the importance of communication policy in this paper we explore some of the economic effects of public information that arise whenever public information serves the dual role of conveying fundamental information as well as serving as a focal point for better coordination more precise public information is a double edged tool while it is very effective in influencing actions through coordination sometimes it can be too effective and coordinate actions away from fundamentals copyright 2002 oxford university press

endogenous public information and welfare in market games this paper performs a welfare analysis of markets with private information in which agents can condition on noisy prices in the rational expectations tradition pricecontingent strategies introduce two externalities in the use of private information a payoff pecuniary externality related to aggregate volatility and a learning externality the impact of the first depends on whether competition is of the strategic substitutes or complements variety and the second induces agents to put too little weight on private information we find that with strategic substitutes and when the learning externality is not very strong agents put too much weight on private information and prices are too informative this will happen in the normal case where the allocational role of price prevails over its informational role under strategic complementarity there is always under reliance on private information the welfare loss at the market solution may be increasing in the precision of private information the analysis provides insights into optimal business cycle policy and a rationale for a tobin like tax for speculators in financial markets

information acquisition and welfare we study information acquisition in a flexible framework with strategic complementarity or substitutability in actions and a rich set of externalities that are responsible for possible wedges between the equilibrium and the efficient acquisition of information first we relate the in efficiency in the acquisition of information to the in efficiency in the use of information and explain why efficiency in the use is no guarantee of efficiency in the acquisition next we show how the acquisition of private information affects the social value of public information i e the comparative statics of equilibrium welfare with respect to the quality of public information finally we illustrate the implications of the results in a monetary economy with price rigidities and dispersed information about productivity shocks

incomplete information higher order beliefs and price inertia the question that motivates this paper is how incomplete information impacts the response of prices to nominal shocks our baseline model is a variant of the calvo model in which firms observe the underlying nominal shocks with noise in this model the response of prices is pinned down by three parameters the precision of available information about the nominal shock the frequency of price adjustment and the degree of strategic complementarity in pricing decisions this result synthesizes the broader lessons of the pertinent literature however this synthesis provides only a partial view of the role of incomplete information once one allows for more general information structures than those used in previous work one cannot quantify the degree of price inertia without data on the dynamics of higher order beliefs or of the agents forecasts of inflation we highlight this with three extensions of our baseline model all of which break the tight connection between the precision of information and higher order beliefs featured in previous work

on the optimal monetary policy response to noisy indicators abstract we describe a behavior of a central bank when its measures of current inflation and output are subject to measurement errors in a framework of optimizing models with nominal price stickiness in our model a central bank sets the interest rate equal to its current estimate of the so called wicksellian natural rate of interest this is shown to imply that the interest rate responds to the central bank s estimates of both current inflation and output gap as advocated by taylor 1993 it is also shown that the noise contained in the indicators justifies a degree of policy cautiousness a reduced form representation of optimal policy should exhibit interest rate smoothing which is often found in the empirical literature on monetary policy reaction functions

tax and education policy in a heterogeneous agent economy what levels of redistribution maximize growth and efficiency this paper studies the effects of progressive income taxes and education finance in a dynamic heterogeneous agent economy such redistributive policies entail distortions to labor supply and savings but also serve as partial substitutes for missing credit and insurance markets the resulting tradeoffs for growth and efficiency are explored both theoretically and quantitatively in a model that yields complete analytical solutions progressive education finance always leads to higher income growth than taxes and transfers but at the cost of lower insurance overall efficiency is assessed using a new measure that properly reflects aggregate resources and idiosyncratic risks but unlike a standard social welfare function does not reward equality per se simulations using empirical parameter estimates show that the efficiency costs and benefits of redistribution are generally of the same order of magnitude resulting in plausible values for the optimal rates aggregate income and aggregate welfare provide only crude lower and upper bounds around the true efficiency tradeoff

the signaling role of policy actions abstract in an economy affected by shocks that are imperfectly known the monetary instrument takes on a dual stabilizing role as a policy response that directly influences the economy and as a vehicle for information that reveals the central bank s assessment to firms because mark up shocks cannot be neutralized by monetary policy providing firms with more information about these shocks exacerbates their reaction and creates a larger distortion recognizing the signaling role of its instrument the central bank distorts its policy response in order to optimally shape firms beliefs while providing firms with more information is always detrimental to the output gap it has a more subtle effect on price dispersion depending on whether information is provided through the transparency channel or through the signaling channel although more transparency is always detrimental to welfare the information that is conveyed by the monetary instrument improves welfare when firms coordination is highly valuable

monetary policy and the information content of prices rational expectations and cleared markets lead to the proposition that feedback monetary policy is irrelevant to real activity as in the analyses of sargent and wallace however if agents are differentially informed and have access to a common price then prospective monetary policy actions future feedback to imperfectly known current circumstances can alter real activity by changing the information content of prices

efficient use of information and social value of information this paper analyzes equilibrium and welfare for a tractable class of economies games that have externalities strategic complementarity or substitutability and heterogeneous information first we characterize the equilibrium use of information complementarity heightens the sensitivity of equilibrium actions to public information raising aggregate volatility whereas substitutability heightens the sensitivity to private information raising cross sectional dispersion next we define and characterize an efficiency benchmark designed to address whether the equilibrium use of information is optimal from a social perspective the efficient use of information reflects the social value of aligning choices across agents finally we examine the comparative statics of equilibrium welfare with respect to the information structure the social value of information is best understood by classifying economies according to the inefficiency if any in the equilibrium use of information we conclude with a few applications including production externalities beauty contests business cycles and large cournot and bertrand games

a theory of demand shocks this paper presents a model of business cycles driven by shocks to consumer expectations regarding aggregate productivity agents are hit by heterogeneous productivity shocks they observe their own productivity and a noisy public signal regarding aggregate productivity the public signal gives rise to noise shocks which have the features of aggregate demand shocks they increase output employment and inflation in the short run and have no effects in the long run numerical examples suggest that the model can generate sizable equilibrium dsge models of the business cycle include a large number of shocks to technol ogy monetary policy preferences etc but typically do not include expectational shocks as independent drivers of short run fluctuations 1 this paper explores the idea of expectation driven cycles looking at a model where technology determines equilibrium output in the long run and consumers receive noisy signals about technology in the short run the presence of noisy signals produces expectational errors this paper studies the role of these expectational errors in gener ating volatility at business cycle frequencies the model is based on two ingredients first consumers take time to recognize permanent changes in aggregate fundamentals although they may have good information on the current state of the individual firm or sector where they operate they have only limited information regarding the long run determinants of aggregate activity second consumers have access to public information that is relevant to estimate long run productivity this includes news about technological innovations publicly released macroeconomic and sectoral statistics financial market prices and public statements by policy makers however these signals provide only a noisy forecast of the long run effects of technological innovations this opens the door to noise shocks which induce consumers to temporarily overestimate or underestimate the productive capacity of the economy

dynamic pricing and imperfect common knowledge abstract introducing private information into the dynamic pricing decision of firms by adding an idiosyncratic component to marginal cost can help explain two stylised facts about price changes aggregate inflation responds gradually and with inertia to shocks at the same time as individual price changes can be large the inertial behaviour of inflation is driven by privately informed firms strategically herding on the public information contained in the observations of lagged aggregate variables the model also matches the average duration between price changes found in the data and it nests the standard new keynesian phillips curve as a special case to solve the model the paper derives an algorithm for solving a class of dynamic models with higher order expectations

managing beliefs about monetary policy under discretion in models of monetary policy discretionary policymaking is typically constrained in its ability to manage public beliefs however when a policymaker possesses private information policy actions serve as signals to the public about unobserved economic conditions and belief management becomes an integral part of optimal discretion policies this article derives the optimal time consistent policy for a general linear quadratic setting the optimal policy is illustrated in a simple new keynesian model where analytical solutions can be derived as well in this model imperfect information about the policymaker s output target leads to lower policy losses

social value of public information comment morris and shin 2002 is actually pro transparency not con the main result of morris and shin 2002 restated in papers by amato morris and shin 2002 and amato and shin 2003 and commented upon by the economist 2004 has been presented and interpreted as an anti transparency result more public information can be bad however some scrutiny of the result shows that it is actually pro transparency except in very special circumstances more public information is good furthermore for a conservative benchmark of equal precision in public and privateinformation social welfare is higher than in as ituation without public information

optimal sticky prices under rational inattention this paper presents a model in which price setting firms decide what to pay attention to subject to a constraint on information flow when idiosyncratic conditions are more variable or more important than aggregate conditions firms pay more attention to idiosyncratic conditions than to aggregate conditions when we calibrate the model to match the large average absolute size of price changes observed in micro data prices react fast and by large amounts to idiosyncratic shocks but only slowly and by small amounts to nominal shocks nominal shocks have strong and persistent real effects we use the model to investigate how the optimal allocation of attention and the dynamics of prices depend on the firms environment jel e 3 e5 d8

information acquisition and learning from prices over the business cycle abstract we study firms incentives to acquire costly information in booms and recessions to investigate the role of endogenous information in accounting for business cycles our model predicts that for a wide range of parameter values firms have a stronger incentive to acquire information when the economy has been in a recession and a pessimistic belief about the state of the economy prevails than after a boom when firms share an optimistic belief the equilibrium price system which features endogenous information transmission dampens aggregate fluctuations by discouraging information acquisition our welfare analysis reveals that information acquisition in the decentralized economy is not efficient this is due to inefficient employment dispersion arising from information heterogeneity in equilibrium time series data for the u s economy support the model s prediction of wages being more informative about total factor productivity after recessions than following booms

implications of rational inattention abstract a constraint that actions can depend on observations only through a communication channel with finite shannon capacity is shown to be able to play a role very similar to that of a signal extraction problem or an adjustment cost in standard control problems the resulting theory looks enough like familiar dynamic rational expectations theories to suggest that it might be useful and practical while the implications for policy are different enough to be interesting

optimal monetary policy with uncertain fundamentals and dispersed information this paper studies optimal monetary policy in a model where aggregate fluctuations are driven by the private sector s uncertainty about the economy s fundamentals information on aggregate productivity is dispersed across agents and there are two aggregate shocks a standard productivity shock and a noise shock affecting public beliefs about aggregate productivity neither the central bank nor individual agents can distinguish the two shocks when they are realized despite the lack of superior information monetary policy can affect the economy s relative response to the two shocks as time passes better information on past fundamentals becomes available the central bank can then adopt a backward looking policy rule based on more precise information about past shocks by announcing its response to future information the central bank can influence the expected real interest rate faced by forward looking consumers with different beliefs and thus affect the equilibrium allocation if the announced future response is sufficiently aggressive the central bank can completely eliminate the effect of noise shocks however this policy is typically suboptimal as it leads to an excessively compressed distribution of relative prices the optimal monetary policy balances the benefits of aggregate stabilization with the costs in terms of cross sectional efficiency copyright wiley blackwell