or practice selecting a portfolio of environmental programs for a synthetic fuels facility this article describes how a u s department of energy steering committee used a decision analysis procedure to develop a portfolio of environmental and health research programs for a commercial scale synthetic fuels facility the procedure used information and insights from decision analyses conducted in five technical areas to support decision analysis at the portfolio level the problem was complex because it included many combinations of studies that could be funded multiple objectives in the five technical areas as well as at the portfolio level and uncertainties about research needs the availability of technical data and research costs the article discusses the rationale for using formal decision analysis the main features of the procedure and how the procedure provided the steering committee with a logical basis for evaluating a large number of diverse technical projects and with the help of health and environmental experts established research priorities and budget allocations in a logical and defensible manner

baseline value specification and sensitivity analysis in multiattribute project portfolio selection abstract a key issue in applying multi attribute project portfolio models is specifying the baseline value a parameter which defines how valuable not implementing a project is relative to the range of possible project values in this paper we present novel baseline value specification techniques which admit incomplete preference statements and unlike existing techniques make it possible to model problems where the decision maker would prefer to implement a project with the least preferred performance level in each attribute furthermore we develop computational methods for identifying the optimal portfolios and the value to cost based project rankings for all baseline values we also show how these results can be used to i analyze how sensitive project and portfolio decision recommendations are to variations in the baseline value and ii provide project decision recommendations in a situation where only incomplete information about the baseline value is available

expectations exchange rates and monetary theory the case of german hyperinflation abstract this paper tests some of the structural coefficient restrictions on goods price equations and foreign exchange rate equations implied by the monetary theory of exchange rates the data are from the german hyperinflation 1922 1923 the results of the tests broadly support the monetary theory of exchange rates and they also support the hypothesis that the foreign exchange market was efficient during this period however the much higher residual volatility in foreign exchange prices is not explained by the monetary theory

towards an attention based view of the firm the central argument is that firm behavior is the result of how firms channel and distribute the attention of their decision makers what decision makers do depends on what issues and answers they focus their attention on what issues and answers they focus on depends on the specific situation and on how the firm s rules resources and relationships distribute various issues answers and decision makers into specific communications and procedures the paper develops these theoretical principles into a model of firm behavior and presents its implications for explaining firm behavior and adaptation 1997 by john wiley sons ltd

inflation and currency depreciation in germany 1920 1923 a dynamic model of prices and the exchange rate this paper presents a dynamic model of the german hyperinflation explaining prices the exchange rate and the money supply in the model estimated simultaneously the nominal exchange rate is allowed to diverge from purchasing power parity in the short run the monetary approach to exchange rate determination and the quantity theory of money are assumed to be valid in the long run the dynamic adjustment of prices and the exchange rate to monetary disturbances is made explicit and currency substitution between domestic and foreign currency is introduced explicitly the problem of the autocorrelation of the residuals of the money demand function found in previous studies is resolved the fit of inflation and exchange rate changes is very satisfactory and the speed of adjustment of the exchange rate to monetary disturbances is found to be much higher than for prices copyright 1995 by ohio state university press

policy change and learning in the rbc model what is the impact of surprise and anticipated policy changes when agents form expectations using adaptive learning rather than rational expectations we examine this issue using the standard stochastic real business cycle model with lump sum taxes agents combine knowledge about future policy with econometric forecasts of future wages and interest rates dynamics under learning can have large impact effects and a gradual hump shaped response and tend to be prominently characterized by oscillations not present under rational expectations these fluctuations reflect periods of excessive optimism or pessimism followed by subsequent corrections

the role of investment specific technological change in the business cycle this is a quantitative investigation of the importance of technological change speci c to new investment goods for postwar us aggregate uctuations a growth model that incorporates this form of technological change is calibrated to us data and simulated using the relative price of new equipment to identify the process driving investmentspeci c technology shocks the analysis suggests that this form of technological change is the source of about 30 of output uctuations 2000 elsevier science b v all rights reserved

a model of housing and credit cycles with imperfect market knowledge abstract the paper presents a model of housing and credit cycles featuring distorted beliefs and comovement and mutual reinforcement between house price expectations and price developments via credit expansion contraction positive negative development in house prices fuels optimism pessimism and credit expansion contraction which in turn boost dampen housing demand and house prices and reinforce agents optimism pessimism bayesian learning about house prices can endogenously generate self reinforcing booms and busts in house prices and significantly strengthen the role of collateral constraints in aggregate fluctuations the model can quantitatively account for the 2001 2008 u s boom bust cycle in house prices and associated household debt and consumption dynamics it also demonstrates that allowing for imperfect knowledge of agents a higher leveraged economy is more prone to self reinforcing fluctuations

model uncertainty and exchange rate volatility this article proposes an explanation for shifts in the volatility of exchange rate returns agents are uncertain about the true data generating model and deal with this uncertainty by making inference on the models and their parameters approach i call model learning model learning may lead agents to focus excessively on a subset of fundamental variables consequently exchange rate volatility is determined by the dynamics of these fundamentals and changes as agents alter models i investigate the empirical relevance of model learning and find that the change in volatility of gbp usd in 1993 was triggered by a shift between models

on the initialization of adaptive learning in macroeconomic models abstract we review and evaluate methods previously adopted in the applied literature of adaptive learning in order to initialize agents beliefs previous methods are classified into three broad classes equilibrium related training sample based and estimation based we conduct several simulations comparing the accuracy of the initial estimates provided by these methods and how they affect the accuracy of other estimated model parameters we find evidence against their joint estimation with standard moment conditions as the accuracy of estimated initials tends to deteriorate with the sample size spillover effects also deteriorate the accuracy of the estimates of the model s structural parameters we show how this problem can be attenuated by penalizing the variance of estimation errors even so the joint estimation of learning initials with other model parameters is still subject to severe distortions in small samples we find that equilibrium related and training sample based initials are less prone to these issues we also demonstrate the empirical relevance of our results by estimating a new keynesian phillips curve with learning where we find that our estimation approach provides robustness to the initialization of learning that allows us to conclude that under adaptive learning the degree of price stickiness is lower compared to inferences under rational expectations

inference in models with adaptive learning abstract identification of structural parameters in models with adaptive learning can be weak causing standard inference procedures to become unreliable learning also induces persistent dynamics and this makes the distribution of estimators and test statistics non standard valid inference can be conducted using the anderson rubin statistic with appropriate choice of instruments application of this method to a typical new keynesian sticky price model with perpetual learning demonstrates its usefulness in practice

the endogeneity of money during the german hyperinflation a reappraisal this paper provides evidence that casts doubt on the conclusioon of several studies of the german hyperinflation that since government raised most of its revenue from money creation the money supply process was endogenous this conclusion in the literature is based on the assumption that the money supply and the price level can be described by linear arima models it is shown here that the linearity assumption is violated by the data and that relaxing this assumption reverses the earlier results the paper provides additional evidence in support of the finding that the money supply process may be exogenous

imperfect information and the house price in a general equilibrium model abstract house prices have inertia which may be because housing market participants need time to recognize long booms and recessions within a dynamic stochastic general equilibrium model with an endogenous market for housing i consider the case of rational expectations subject to imperfect information about the persistence of exogenous shocks i evaluate the performance of the model against the last 40 years of key u s macroeconomic data bayesian comparison strongly favors the model over the baseline case with perfect information under imperfect information agents rely on learning to form expectations which improves the ability of the model to generate realistic low frequency house price dynamics however as long as the agents form expectations rationally the improvement is limited furthermore to confine price inertia within the housing market is a challenge for the general equilibrium approach

current real business cycle theories and aggregate labor market fluctuations hours worked and the return to working are weakly correlated traditionally the ability to account for this fact has been a litmus test for macroeconomic models existing real business cycle models fail this test dramatically we modify prototypical real business cycle models by allowing government consumption shocks to influence labor market dynamics this modification can in principle bring the models into closer conformity with the data our empirical results indicate that it does

expectations learning and business cycle fluctuations this paper explores an alternative theory based on learning dynamics in the con text of an otherwise standard stochastic growth model we consider an environment in which households and firms have an incomplete model of the macroeconomy knowing only their own objectives constraints and beliefs agents are optimizing have a completely specified belief system but do not know the equilibrium map ping between primitive disturbances the aggregate state of the economy and mar ket clearing prices by extrapolating from historical patterns in observed data they approximate this mapping to forecast variables that are exogenous to their decision problems such as the rental rate of capital and the real wage this belief structure has the property that beliefs affect the true data generating process of the economy which in turn affects belief formation the economy is therefore self referential shifts in beliefs about future returns to labor and capital affect current market clear ing prices which in turn can reinforce beliefs in this environment current prices can become less informative about future economic conditions generating fluctuations in real activity this kind of mechanism driving business cycle fluctuations is found in early writ ings on macroeconomic dynamics for example alfred c pigou 1927 on page 122 writes

the great inflation and the greenbook abstract can the story of evolving federal reserve beliefs in the conquest of american inflation simultaneously explain the great inflation and the forecasts published in the greenbook during that time if sargent is correct then evolving beliefs should be reflected not only in policy outcomes but also in greenbook forecasts in this paper they are by conditioning on the greenbook it is show that both inflation outcomes and greenbook forecasts can be rationalised by evolving beliefs the results improve on recent empirical evidence that has been criticised for relying on unrealistic beliefs that produce forecasts inconsistent with the greenbook

behavioral learning equilibria we propose behavioral learning equilibria where boundedly rational agents learn to use a simple univariate linear forecasting rule with correctly specified unconditional mean and first order autocorrelation in the long run agents learn the best univariate linear forecasting rule without fully recognizing the more complex structure of the economy an important feature of behavioral learning equilibria is simplicity and parsimony which makes coordination of individual expectations on such an aggregate outcome more likely in a first application an asset pricing model driven by ar 1 ar 1 dividends a unique behavioral learning equilibrium exists characterized by high persistence and excess volatility and it is stable under learning in a second application the new keynesian phillips curve multiple equilibria coexist learning exhibits path dependence and inflation may switch between low and high persistence regimes

modeling synergies in multi criteria supplier selection and order allocation an application to commodity trading abstract we propose a novel meta approach to support collaborative multi objective supplier selection and order allocation ssoa decisions by integrating multi criteria decision analysis and linear programming lp the proposed model accounts for suppliers performance synergy effects within a hierarchical decision structure it incorporates both heterogeneous objective data and subjective judgments of the decision makers dms representing various groups with different voting powers vps we maximize the total value of purchasing tvp by optimizing order quantity assignment to suppliers and taking into consideration their synergies encountered in different time horizons we apply the proposed model to a contractor selection and order quantity assignment problem in an agricultural commodity trading act company we maximize the strategic effectiveness of both the customers and the suppliers minimize risks increase the degree of cooperation between trading partners on all levels of supply chain integration enhance transparent knowledge sharing and aggregation and support collaborative decision making

structuring resource allocation decisions a framework for building multi criteria portfolio models with area grouped options multi criteria portfolio modelling has been extensively employed as an effective means to allocate scarce resources for investment in projects when considering costs benefits and risks some of these modelling approaches allow the grouping of projects into organisational areas thus also supporting the decision of resource allocation among organisational units in a way that is collectively efficient for the organisation however structuring in practice a portfolio model using this latter type of approach is not a trivial task how should areas be defined where should new projects be included how should one define the criteria to evaluate performance as far as we know there is very little indication in the operational research and decision sciences literatures on how to structure this type of model this paper suggests different ways to structuring portfolio models where projects are divided into areas and evaluated by multiple criteria and illustrates their use in two action research projects drawing on these experiences it then suggests a general framework for the structuring of such models in practice directions for future research are also identified

preference programming for robust portfolio modeling and project selection in decision analysis difficulties of obtaining complete information about model parameters make it advisable to seek robust solutions that perform reasonably well across the full range of feasible parameter values in this paper we develop the robust portfolio modeling rpm methodology which extends preference programming methods into portfolio problems where a subset of project proposals are funded in view of multiple evaluation criteria we also develop an algorithm for computing all non dominated portfolios subject to incomplete information about criterion weights and project specific performance levels based on these portfolios we propose a project level index to convey i which projects are robust choices in the sense that they would be recommended even if further information were to be obtained and ii how continued activities in preference elicitation should be focused the rpm methodology is illustrated with an application using real data on road pavement projects

escaping nash inflation an ordinary differential equation ode gives the mean dynamics that govern the convergence to self confirming equilibria of self referential systems under discounted least squares learning another ode governs escape dynamics that recurrently propel away from a self confirming equilibrium in a model with a unique self confirming equilibrium the escape dynamics make the government discover too strong a version of the natural rate hypothesis the escape route dynamics cause recurrent outcomes close to the ramsey commitment inflation rate in a model with an adaptive government

learning large deviations and recurrent currency crises this article studies a version of obstfeld s journal of international economics 43 1997 61 77 escape clause model the model is calibrated to produce three rational expectations equilibria two of these equilibria are e stable and one is unstable dynamics are introduced by assuming that agents must learn about the government s decision rule it is assumed they do this using a stochastic approximation algorithm it turns out that as a certain parameter describing the sensitivity of beliefs to new information gets small the algorithm converges to a small noise diffusion process the dynamics of exchange rate changes are then characterized using large deviation techniques from freidlin and wentzell random perturbations of dynamical systems second edition berlin springer verlag 1998 these methods describe the sense in which the limiting distribution of exchange rate changes is approximated by a two state markov switching process where the two states correspond to the two e stable equilibria the model is calibrated to the exchange rate histories of argentina brazil and mexico currency crises in these countries resemble the predicted escape routes of the model a key feature of these escape routes is that expectations of a devaluation erupt suddenly without large contemporaneous shocks this is consistent with evidence showing that crises are often poorly anticipated by financial markets

the conquest of south american inflation we infer determinants of latin american hyperinflations and stabilizations by using the method of maximum likelihood to estimate a hidden markov model that assigns roles both to fundamentals in the form of government deficits that are financed by money creation and to destabilizing expectations dynamics that can occasionally divorce inflation from fundamentals levels and conditional volatilities of monetized deficits drove most hyperinflations and stabilizations with a notable exception in peru where a cosmetic reform of the type emphasized by marcet and nicolini occurred

the demand for money the reform effect and the money supply process in hyperinflation the evidence from greece and hungary ii reexamined newly uncovered data on money and prices in greece and hungary duri ng their hyperinflations are used to reestimate the cagan money demand equation and to repeat the sargent and wallace causality tests it is no longer necessary to exclude observations at the end of each episo de on the premise that they represent the response to an anticipated monetary reform the results for each country now conform to the sargent and wallace findings for most other hyperinflation episodes that causality runs from prices to money i e that money is endogenous copyright 1988 by ohio state university press

are hyperinflation paths learnable abstract earlier studies of the seigniorage inflation model have found that the high inflation steady state is not stable under learning we reconsider this issue and analyze the full set of solutions for the linearized model our main focus is on stationary hyperinflationary paths near the high inflation steady state these paths are shown to be stable under least squares learning if agents can utilize contemporaneous data in an economy with a mixture of agents some of whom only have access to lagged data stable hyperinflationary paths emerge only if the proportion of agents with access to contemporaneous data is sufficiently high

learning adaptive expectations and technology shocks this study explores the macroeconomic implications of adaptive expectations in a standard growth model we show that the self confirming equilibrium under adaptive expectations is the same as the steady state rational expectations equilibrium for all admissible parameter values but that dynamics around the steady state are substantially different between the two equilibria the differences are driven mainly by the dampened wealth effect and the strengthened intertemporal substitution effect not by escapes emphasised by williams 2003 consequently adaptive expectations can be an important source of frictions that amplify and propagate technology shocks and seem promising for generating plausible labour market dynamics

adaptive behavior and economic theory the relationship between psychological and economic views of behavior once a subject of heavy dispute is now understood in a very similar way by practitioners of both these disciplines and of our sister social sciences in general terms we view or model an individual as a collection of decision rules rules that dictate the action to be taken in given situations and a set of preferences used to evaluate the outcomes arising from particular situation action combinations these decision rules are continuously under review and revision new decision rules are tried and tested against experience and rules that produce desirable outcomes supplant those that do not i use the term adaptive to refer to this trial anderror process through which our modes of behavior are determined if one is interested in modeling particular decisions in any very explicit way it is obviously necessary to think about rather narrow aspects of an individual s entire set of decision rules his or her personality experimental psychology has traditionally focused on the adaptive process by which decision rules are replaced by others in this tradition the influence of the subject s or as an economist says the agent s preferences this essay uses a series of examples to illustrate the use of rationality and adaptation in economic theory it is argued that these hypotheses are complementary and that stability theories based on adaptive behavior may help to narrow the class of empirically interesting equilibria in certain economic models an experiment is proposed to test this idea

selecting a portfolio of solar energy projects using multiattribute preference theory this article reports a procedure developed to assist the u s department of energy in selecting a portfolio of solar energy applications experiments the procedure has also been used in other government procurements and appears to be applicable in a variety of project funding processes the technical quality of each proposed applications experiment was summarized through the use of multiple evaluation measures or attributes these were combined into a single index of the overall technical quality of an experiment through the use of a multiattribute utility function recently derived results in measurable value theory were applied to derive an index of the overall technical quality of a portfolio of experiments budgetary and programmatic issues were handled through the use of constraints this approach allowed the portfolio selection problem to be formulated as an integer linear program details of the application are presented including a discussion of the data requirements and assessment procedure used the portfolio selection procedure was successfully applied and variations of it have been successfully used in four other solar energy procurements

learning and shifts in long run productivity growth abstract an extensive literature has analyzed the macroeconomic effects of shocks to the level of aggregate productivity however there has been little corresponding research on sustained shifts in the growth rate of productivity in this paper we examine the effects of shocks to productivity growth in a dynamic general equilibrium model where agents do not directly observe whether shocks are transitory or persistent we show that an estimated kalman filter model using real time data describes economists long run productivity growth forecasts in the united states extremely well and that filtering has profound implications for the macroeconomic effects of shifts in productivity growth

recurrent hyperinflations and learning we use a model of boundedly rational learning to account for the observations of recurrent hyperinflations in the 1980 s in a standard monetary model we replace the assumption of full rational expectations by a formal definition of quasi rational learning the model under learning matches some crucial stylized facts observed during the recurrent hyperinflations experienced by several countries in the 1980 s remarkably well we argue that despite being a small departure from rational expectations quasi rational learning does not preclude falsifiability of the model it does not violate reasonable rationality requirements and it can be used for policy evaluation

expectation volatility and liquidity in the housing market measuring housing price volatility is fundamental to understanding the dynamics of housing price risk this article aims to explore whether a liquidity factor plays a role in explaining the second moment i e the volatility of housing prices housing price volatility is measured as the conditional variance of a generalized auto regressive conditional heteroscedasticity garch model under the adaptive expectations framework the empirical evidence reveals that volatility transmits from smaller housing units to larger housing units which indirectly supports the trade up effect discussed in the literature in addition less liquid housing classes are more sensitive to unexpected liquidity shocks and the starter housing class is extraordinarily sensitive to negative liquidity shocks consistent with friction search theory pricing errors are alleviated as the trading volume increases because the valuation price tends to be more accurate as more information is available

long run implications of investment specific technological change an attempt is made to disentangle its effects from the more traditional hicksneutral form of technological progress the balanced growth path for the model is characterized and calibrated to u s national income and product account nipa data the quantitative analysis suggests that investment specific technological change accounts for the major part of growth jel e13 030 041 047

unpacking multimethodology impacts of a community development intervention multimethodology interventions are being increasingly employed by operational researchers to cope with the complexity of real world problems in keeping with recent calls for more research into the realised impacts of multimethodology we present a detailed account of an intervention to support the planning of business ideas by a management team working in a community development context drawing on the rich steam of data gathered during the intervention we identify a range of cognitive task and relational impacts experienced by the management team during the intervention these impacts are the basis for developing a process model that accounts for the personal social and material changes reported by those involved in the intervention the model explains how the intervention s analytic and relational capabilities incentivise the interplay of participants decision making efforts and integrative behaviours underpinning reported intervention impacts and change our findings add much needed empirical case material to enrich further our understanding of the realised impacts of operational research interventions in general and of multimethodology interventions in particular

why inflation rose and fell policy makers beliefs and u s postwar stabilization policy this paper provides an explanation for the run up of u s inflation in the 1960s and 1970s and the sharp disinflation in the early 1980s which standard macroeconomic models have difficulties in addressing i present a model in which rational policymakers learn about the behavior of the economy in real time and set stabilization policy optimally conditional on their current beliefs the steady state associated with the self confirming equilibrium of the model is characterized by low inflation however prolonged episodes of high inflation ending with rapid disinflations can occur when policymakers underestimate both the natural rate of unemployment and the persistence of inflation in the phillips curve i estimate the model using likelihood methods the estimation results show that the model accounts remarkably well for the evolution of policymakers beliefs stabilization policy and the postwar behavior of inflation and unemployment in the united states

long run growth uncertainty observed macroeconomic forecasts display a positive correlation between expectations of long run growth of endogenous variables e g output and cyclical activity existing business cycle models appear inconsistent with the evidence this paper presents a model of the business cycle in which households have imperfect knowledge of long run growth rate of endogenous variables and continually learn about these growth rates the model features comovement and mutual influence between households growth expectations and market outcomes it can replicate the evidence on growth forecasts and suggests that optimism and pessimism about long run growth rates is a crucial ingredient in understanding business cycle fluctuations

the dynamic effects of neutral and investment specific technology shocks the neoclassical growth model is used to identify the short run effects of neutral technology shocks which affect the production of all goods homogeneously and investment specific shocks which affect only investment goods the real equipment price crucial for identifying the investment shocks experiences an abrupt increase in its average rate of decline in 1982 so the analysis is based on a split sample on the basis of the preferred specification the two technology shocks account for 73 percent of hours and 44 percent of output s business cycle variation before 1982 and 38 percent and 80 percent afterward the shocks also account for more than 40 percent of hours and 58 percent of output s forecast errors over a three to eight year horizon in both samples the majority of these effects are driven by the investment shocks

money credit and wages in hyperinflation post world war i germany an important feature of the german hyperinflation is the way in which accelerating monetization of both government and private debt by the reichsbank fueled the inflation process the stimulus to private credit demand arising from more rapid adjustment of money wages over this period is often ignored however the present empirical results strongly support the importance of wage pressures in augmenting fiscal influences on nominal money growth during 1920 1923 our findings also suggest that wage claims provided the main conduit through which higher inflationary expectations were accommodated by faster rates of monetary expansion

shocks and government beliefs the rise and fall of american inflation working paper 2004 22 september 2004 abstract the authors use a bayesian markov chain monte carlo algorithm to estimate a model that allows temporary gaps between a true expectational phillips curve and the monetary authority s approximating nonexpectational phillips curve a dynamic programming problem implies that the monetary authority s inflation target evolves as its estimated phillips curve moves the authors estimates attribute the rise and fall of post world war ii inflation in the united states to an intricate interaction between the monetary authority s beliefs and economic shocks shocks in the 1970s altered the monetary authority s estimates and made it misperceive the tradeoff between inflation and unemployment that misperception caused sharp rise in inflation in the 1970s the authors estimates indicate that policy makers updated their beliefs continuously by the 1980s policy makers beliefs about the phillips curve had changed enough to account for fed chairman paul volcker s conquest of u s inflation in the early 1980s jel classification e3 e5 key words updating beliefs policy evaluation self confirming equilibrium nash inflation ramsey outcomes i introduction today many statesmen and macroeconomists believe that inflation can largely be determined by a government monetary authority then why did the federal reserve board preside over high us inflation during the late 1960s and the 1970s and why under paul volcker did it rapidly bring inflation down during the early 1980s this paper answers these questions by estimating a model that features a particular process that makes a procession of economic shocks induce the monetary authority to alter its model of inflation unemployment dynamics the phillips curve at each date t the monetary authority updates its beliefs about the phillips curve and then recomputes a first period action recommended by a phelps problem a discounted dynamic programming problem that minimizes the expected value of a discounted quadratic loss function of inflation and unemployment 1 the monetary authority pursues the same objectives at each date using the same structural model with only its estimates of that model changing over time 2 this model of the systematic part of inflation puts the monetary authority s beliefs about the phillips curve front and center 3 we assume that the monetary authority s model of the phillips curve deviates in two subtle but important ways from what it would be in a rational expectations model e g kydland and prescott 1977 the first deviation is that while the true phillips curve is like kydland and prescott s we assume that the monetary authority omits the public s expected rate of inflation from its phillips curve by itself this omission need not prevent the outcomes of our model from coinciding with those of kydland and prescott s nor need it imply that the government s model is wrong in a way that could be detected from even an infinite sample whether the monetary authority s model is wrong in a statistically detectable way depends on how we allow the monetary authority to reestimate the parameters of its model in particular if the monetary authority were to believe that the coefficients of its phillips curve are constant over time then its estimates would converge to ones that support a self confirming equilibrium sce after convergence its estimated phillips curve would correctly describe occurrences along the sce path for inflation and unemployment such an after convergence version of our model has little hope of explaining the rise and fall of us inflation that model would have inflation fluctuating randomly around a constant sce level that coincides with kydland and prescott s time consistent suboptimal i e excessive level 4 this outcome motivates our second subtle deviation from a rational expectations equilibrium

empirical calibration of adaptive learning abstract adaptive learning introduces persistence in the evolution of agents beliefs over time helping explain why economies present sluggish adjustments towards equilibrium the pace of this learning process is directly determined by the gain parameter we document and evaluate gain calibrations for a broad range of model specifications with macroeconomic data also developing alternative approaches to the endogenous determination of time varying gains in real time our key findings are that learning gains are higher for inflation than for output growth and interest rates and that calibrations to match survey forecasts are lower than those derived according to forecasting performance suggesting some degree of bounded rationality in the speed with which agents update their beliefs