interpreting economic time series this paper explores some of the implications for econometric practice of the principle that people s observed behavior will change when their constraints change in dynamic contexts a proper definition of people s constraints includes among them laws of motion that describe the evolution of the taxes they must pay and the prices of the goods that they buy and sell changes in agents perceptions of these laws of motion or constraints will in general produce changes in the schedules that describe the choices they make as a function of the information that they possess until very recently received dynamic econometric practice ignored this principle the practice of dynamic econometrics should be changed so that it is consistent with the principle that people s rules of choice are influenced by their constraints this is a substantial undertaking and involves major adjustments in the ways that we formulate estimate and simulate econometric models

the monetary approach to exchange rate determination under rational expectations the dollar deutschmark rate abstract this paper reformulates the monetary approach after ascertaining that a money demand function with a partial adjustment mechanism had more empirical support than a money demand function which assumed instantaneous stock adjustment the resulting exchange rate equation is estimated by two rational expectations techniques the parameter estimates are reasonable and are robust to the estimation technique used to different specifications of the driving processes and to changes in the estimation period the structural model outperforms the random walk model and its own unconstrained equivalent a pure time series equation in outof sample forecasts

interpreting an error correction model partial adjustment forward looking behaviour and dynamic international money demand an error correction model is derived from a stochastic dynamic programming problem incorporating rational expectations a parametric restriction is derived that allows a test for the theoretical proposition that the optimal strategy behind the error correction from entails the failure to asymptotically close the gap between the choice variable and the growing target this is accomplished by nesting a partial adjustment model with forward looking expectations within the error correction paradigm the counterintuitive behaviour embodied in the error correction model is not supported by the data in the context of a cross country comparison of cash balances relationships

measures of fit for rational expectations models this survey provides a detailed description of some of the recent theoretical and empirical literature on rational expectations econometrics the survey pays special attention to non stationarity of the data and to the various methods for evaluating rational expectations models that have been developed as alternatives to the classical statistical approach of testing overidentifying restrictions these methods have become very popular and widely used in empirical research we provide an illustration using danish stock market data and we summarize the many results obtained recently using these measures in areas as diverse as stock prices the term structure of interest rates exchange rates consumption and saving the balance of payments tax smoothing hyperinflation and linear quadratic adjustment cost models for inventories labour demand and money demand

the behaviour of u k export prices of manufactured goods 1970 1983 this paper examines the importance of expectations in the determination of u k export prices export prices are found to depend upon expectations of total domestic unit costs and foreign prices the non linear restrictions implied by the forward looking model are found to hold and it performs adequately relative to a backward looking error feedback model the law of one price is rejected and the evidence is consistent with imperfect competition in export markets

the production and inventory behavior of the american automobile industry understanding inventory movements is central to an understanding of business cycles this paper presents an empirical study of the behavior of inventories in the automobile industry it finds that inventory behavior is well explained by the assumption of intertemporal optimization with rational expectations the underlying cost structure appears to have substantial costs of changing production as well as substantial costs of being away from target inventory thelatter being a function of current sales given this cost structure whether inventory behavior is stabilizing or destabilizing depends on the characteristics of the demand process in the automobile industry inventory behavior is destabilizing the variance of production is larger than the variance of sales

international dynamic risk sharing in this paper we examine the implications of international risk sharing among a set of countries in the presence of market frictions which complicate the instantaneous adjustment to the first order conditions we suggest approximating the consumption streams of countries belonging to the risk sharing coalition in terms of a disequilibrium dynamic model embodying forward looking adjustment econometric methods for estimating and testing the model are discussed empirical analysis of a set of core european countries suggests that once preference parameters are allowed to vary across countries we are able to identify a group of nations that share risks against idiosyncratic permanent income shocks the equilibrium position however is reached after a long adjustment period copyright 2008 john wiley sons ltd

prices output and hours an empirical analysis based on a sticky price model abstract i show that a simple sticky price model based on rotemberg 1982 is consistent with a variety of facts concerning the correlation of prices hours and output it is consistent with the negative correlation between forecastable movements in prices and output as well as the smaller negative correlation between forecastable movements in prices and hours it is also consistent with the positive correlations of unexpected movements in prices output and hours these patterns are harder to reconcile with the flexible price version of the model in particular they require that money respond differently to forecastable and to unforecastable real shocks

eu economic partnership agreements and wto negotiations a quantitative assessment of trade preference granting and erosion in the banana market the paper provides a quantitative assessment of the impact on the banana market of the expansion of trade preferences the european union granted africa caribbean and pacific acp countries with the economic partnership agreements epa and of the possible erosion of these preferences as a result of different possible conclusions if any of on going wto negotiations the results of the simulations performed suggest that the impact of the epa on production and consumption of bananas in the eu will be limited while benefits for acp countries will be significant at the expense of most favoured nation mfn exporters an agreement between the eu and mfn countries to end the outstanding wto disputes on bananas and or the conclusion of the wto doha round may bring an erosion of the preferential margins currently enjoyed by acp countries of such an order of magnitude as to cancel out most of these benefits

the expectations hypothesis of the term structure the uk interbank market using a high quality weekly data set the author provides several tests of the expectations hypothesis using the vector autoregression and cointegration methodologies for several maturities between one week and twelve months for the u k interbank market on the basis of the johansen cointegration analysis there appears to be a break in the term structure when both the six month and twelve month maturities are included as a pair the latter may be due to either the presence of liquidity constraints or market segmentation or a time varying term premium all of which would invalidate the assumptions underlying the expectations hypothesis the author provides some tentative explanations of these diverse results copyright 1996 by royal economic society

on the reinterpretation of money demand regressions a stylized fact concerning estimated money demand relationships is that lagged dependent variables have high explanatory power and large estimated coefficients which is hard to explain at a theoretical level marvin s goodfriend 1985 suggests that this may be due to the presence of serially correlated measurement errors in the independent variables the author demonstrates how consistent estimates of the short run demand function can be obtained even if the goodfriend hypothesis is accepted and also how the hypothesis might be tested application of the suggested test using the goldfeld 1973 data set leads to decisive rejection of the hypothesis copyright 1994 by ohio state university press

a dynamic model of money credit and consumption a joint model for the uk household sector previous research has investigated consumers expenditure and money demand as separable equations we estimate them jointly as driven by the same influences credit is also included as a potential third variable that might provide a source of additional information about the monetary transmission mechanism consumption money and lending equations are modelled as an interdependent system and the significance of lending for consumption andmoney is tested theresults using uk household sector data show that a stable credit equation does exist in parallel with money demand and consumption equations and that interactions modelled in a conditional vector equilibrium correction system are favoured over independent equations

dynamic specifications in optimizing trend deviation macro models abstract as noted in surveys by goodfriend and king in b bernanke j rotemberg eds nber macroeconomics annual mit press cambridge ma 1997 pp 231 283 and walsh monetary theory and policy mit press cambridge ma and exemplified by models analyzed in taylor 1999 there is encouraging progress in developing optimizing trend deviation macro models that provide useful insights into the transmission and design of monetary policy several controversial features of a minimalist trend deviation model with optimizing households firms and bond traders are examined dynamic specifications are suggested to improve the data based realism while preserving the simplicity of the minimalist model

dynamic labour demand using error correction model using a new econometric model this study provides evidence that contradicts previous assertions about the japanese labour market the interrelationship between employment and hours of labour is stressed in this analysis by explicitly dividing labour input into both employment and labour hours this model enables results to be obtained through both simulation and estimation which allow measurement of adjustment speeds and elasticity in both employment and labour hours to wages the results of the simulations are as follows no apparent difference in adjustment speeds between employment and hours of labour was found the adjustment of hours of labour is more cyclical and overshoots whereas that of employment is smoother the adjustment speed of each simulation is slower than that found in most previous studies in the present long run simulation it is not as slow in the short run and policy simulations therefore adjustment speeds strongly depend on the method of simulation

partial adjustment in the demand for money theory and empirics central to the notion of money as the medium of exchange is the concept that all transactions are conducted using money balances this notion expounded most explicitly by robert clower 1967 1970 has led to the development over the past decade of interesting models of the transactions and precautionary demand for money these have examined optimal behavior of the economic agent in steady state although there has been much gained by examining money balance behavior in this way money demand models so far have ignored the behavior of money during periods of disequilibrium an adequate understanding of total money balances is possible only by incorporating both equilibrium and disequilibrium behavior into an overall view in this regard michael darby 1972 is exceptional in explicitly treating disequilibrium money demand behavior darby s paper is mainly empirical but it contains an interesting intuitive discussion of money s role as a shock absorber during periods of disequilibrium in the present study we address both the theoretical foundation and empirical importance of the shock absorber effect we construct a model of optimal behavior by the economic agent showing the necessary conditions for the existence of partial adjustment and indicating how the intensity of adjustment behaves over time and in response to changes in economic variables this appears to be the first such attempt in the money demand literature although there is related work in the investment literature on the flexible accelerator we test the model on u s quarterly data to estimate the existence and magnitude of partial adjustment we find a significant but small effect for both ml and m2 furthermore the effect dies out within one and two quarters for the respective definitions of money the results thus support but disagree in magnitude with those of darby 1972 who found a larger and longer lasting partial adjustment effect our finding of so short an effect is especially important in light of robert barro s 1978 paper which relies on darby s long lasting effect to explain price behavior

demand for money and expected inflation the role of the expected rate of inflation in the demand for money has been highly controversial both at the theoretical and the empirical level this note critically discusses these issues and puts forward a hypothesis accounting for the significance of expected inflation in money demand equations which is corroborated by an empirical investigation of the italian experience particularly suited for this specific experiment

the conduct of monetary policy nowadays the central bank of a country is the monopoly supplier of legal tender currency the commercial banks are committed to making their deposits convertible at par into such currency so the banks need to keep reserves in the form of currency and deposits at the central bank the central bank primarily conducts its policy by buying and selling financial securities e g treasury bills or foreign exchange in exchange for its own liabilities i e open market operations academic economists generally regard such operations as adjusting the quantitative volume of the banks reserve base and hence of the money stock with rates prices in such markets simultaneously determined by the interplay of demand and supply central bank practitioners almost always view themselves as unable to deny the banks the reserve base that the banking system requires and see themselves as setting the level of interest rates at which such reserve requirements are met with the quantity of money then simultaneously determined by the portfolio preferences of private sector banks and non banks this difference in perceptions is discussed again in section iii whether the monetary policy operations of central banks should be viewed primarily in terms of quantity or rate setting actions though of course one is the dual of the other these had allowed inflation and inflationary expectations to become entrenched by the end of the i970s a selection of representative statistics for a number of the leading industrialised countries is given in table i below this table indicates a common pattern among the countries of interaction between interest rates inflation and the growth of output the first period i969 78 is marked by high inflation negative real interest rates and slightly above average growth the second period i979 82 by very high nominal and high real interest rates high but falling inflation and very low output growth the final period i983 7 is marked by much lower inflation lower nominal but still high real interest rates and a recovery in output growth in some cases to above average rates in contrast the relationship in these countries between the growth of their chosen key monetary aggregate and nominal incomes appears much weaker also see clinton and chouraqui i987 especially p 7 whether measured in terms of monetary growth or in terms of real interest rates i e after adjustment for prospective future inflation policy during the

the dynamics of agriculture supply a reconsideration this paper presents a dynamic rational expectations equilibrium model for a given crop the dynamic supply equation is derived from the farmer optimization problem and the equilibrium movements of commodity price production and land allocations are solved analytically it is shown that the observed dynamics of agriculture supply which are usually explained and measured with the nerlovian supply response model can be explained and measured at least as well by the rational expectations equilibrium model however interpretation of the results is different and the paper defines explicitly the dynamic supply elasticities and presents an econometric method for consistent estimators for the parameters

increasing returns and the foundations of unemployment theory current approaches to macroeconomic theory divide roughly into two basic schools of thought one approach typically associated with rational expectations views the economy as basically at or near walrasian market clearing equilibrium in which case it becomes very difficult to explain away convincingly the undeniable persistence at times of involuntary unemployment another approach views the underemployed economy as being in a state of temporary fixed price disequilibrium in which case aside from having to repress suspicions that the essence of effective demand failure might not have to do with prices fixed at wrong values there is a lot of rationalising to be done about why profitable adjustments are so slow this paper argues that something like an internally consistent theory of steady state involuntary unemployment is possible and even plausible the cornerstone of this third approach is increasing returns to scale which blocks unemployed agents from breaking out of a low level equilibrium trap unless there is overall coordination or stimulation a simple model is presented which contains the basic ideas

the efficient estimation of econometric models with rational expectations the efficient estimation of econometric models with rational expectations by the substitution method usually entails the use of a non linear simultaneous equations estimator and hence is not very attractive computationally it is shown that for a wide class of problems efficient estimates can also be obtained with standard estimation methods if instead an errors in variables approach is used for many other problems although not providing fully efficient estimates because rationality is not imposed the errors in variables method will still have a strong appeal because otherwise it uses all of the structural information in the model unlike the substitution method when an incomplete information set is used it guarantees consistent estimates and it is easy to compute

tariff preferences wto negotiations and the ldcs the case of the everything but arms initiative by assessing the impact of the recently adopted everything but arms eba initiative of the eu on the least developed countries ldcs and by showing how further multilateral trade liberalisations erode the eba preferences and impact the ldcs this paper attempts to uncover the ldcs difficult positions in the wto trade negotiations due to its limited product coverage and previous preferences granted by the eu welfare impacts of the eba on the ldcs are shown to be small and the bulk of these gains are associated with the sensitive products that are subject to gradual liberalisations moreover these small gains are likely to disappear if the eu conducts trade policy reforms in fulfilling its wto obligations resulting in an actually worse off situation for the ldcs extending the analysis to a multilateral trade liberalisation scenario reinforces the above results that the ldcs may well lose due to preference erosion and higher world market prices it concludes that other development assistance measures from developed countries should be made available to the ldcs to ease their dependency on trade preferences and to foster their supply capacities the ldcs themselves should attempt to integrate the duty and quota free market access status contained in the eba into a binding wto agreement to secure a stable trading environment but more importantly in order to solve the difficulties at the root these countries should actively engage in reforming their own trade policies

are farrowing intentions rational forecasts this paper tests whether quarterly data on hog farmers sow farrowing intentions released in hogs and pigs are rational forecasts of actual farrowings the empirical results show that neither one nor two quarter ahead intentions are rational forecasts econometric methods and the implications of the empirical results for the rational expectations hypothesis are also discussed

multivariate detrending under common trend restrictions implications for business cycle research abstract this paper outlines a methodology to detrend multiple time series under common trend restrictions the same filters used to construct the estimated trend in univariate exercises are shown to be appropriate in multivariate studies with a single common trend however to estimate the common trend in the multivariate case the filter is applied to a linear combination of series rather than to each series individually an empirical example and simulation exercises illustrate the implications of common trend detrending for measurement of business cycle properties

the determinants of manufacturing inventories in the uk the authors examine the determinants of inventory holding by the u k manufacturing sector over the period 1968 89 they find that inventory levels respond positively to output and its conditional variance and negatively to the level of gearing tehnological innovation in the form of computerized inventory control leads to a fall in the stock output ratio epirical results for inventories are examined in a cointegration and a general to specific error correction model with conditional variances estimated using an arch framework a backward looking error correction model is found to outperform a forward looking model although the latter also provides a reasonable fit to the data copyright 1993 by royal economic society

assessing the impact of unilateral trade policies eba and agoa on african beneficiaries exports using matching econometrics the existing literature studying the impact of non reciprocal preferential trade agreements nrptas assumes implicitly nrptas are non randomly assigned without showing the evidence of that using a matching methodology this paper investigates whether the african growth and opportunity act agoa and the everything but arms eba unilateral trade concessions have had an impact and in what magnitude on the exports of african beneficiary countries in the light of the evidence of the non random nature endogeneity of nrptas methodologically previous studies using the matching procedure focused on bi or multilateral trade agreements our work focuses on nrptas that depend only on donors conditions accordingly we show that for nrptas gravity covariates cannot be used for the matching procedure we propose to use political variables as determinants for obtaining non reciprocal trade preferences in order to address the endogenous nature of nrpta assignment our main results confirm that a country becomes eligible for a nrpta only when it meets certain conditions defined by their donors such as political stability and economic regulation for agoa and freedom of expression and human development for eba results also show that both agoa and eba policies have had a positive impact on african beneficiary countries exports to nrpta s providers even if the magnitude impact of eba is significantly lower than that of agoa

foreign currency deposits and the demand for money in developing countries abstract this paper examines the relative demands for domestic and foreign currency deposits by residents of developing countries a dynamic currency substitution model that incorporates forward looking rational expectations is specified and estimated for a group of ten developing countries the results indicate that the foreign rate of interest and the expected rate of depreciation of the parallel market exchange rate are important factors in the choice between holding domestic money or foreign currency deposits abroad furthermore the model appears to fit the data better than a conventional partial adjustment model

the demand for money a rational expectations approach the authors derive a model of money demand for an optimizing consumer with rational expectations in a discrete time infinte hortizon framework under uncertainty mone y demand responds to unanticipated changes in income one period expe ctations of future bond and money interest rates unanticipated curre nt interest rates and past anticipations of current rates the deriv ed consumption function mirrors money demand behavior joint estimati on of the consumption and money demand equations by weighted nonlinea r least squares corroborates the predicted effects particularly inco me neutrality this money demand model substantially outperforms a co nventional specification in post sample simulation over 1975 85 copyright 1988 by mit press

on long run solutions to dynamic econometric equations under rational expectations models of this type abound in the re literature and include inter alia the permanent income model of consumption hall i 978 sargent i 978 a models of factor demand sargent i978 b portfolio balance during hyperinflations sargent i977 foreign exchange rate determination mussa i976 i982 the term structure of interest rates shiller i972 modigliani and shiller i973 and the demand for money cuthbertson and taylor i987 the general formulation and estimation of such models is discussed in hansen and sargent i 980 in particular this type of equation arises naturally in models displaying the familiar re saddle path properties where the unstable root is solved forward sargent i979 if we define x zt i a e ai xt i o 3 may be written yt kytt1 te t et

an alternative approach to the american demand for money with a decade of evidence behind it the profession seems to have agreed on the fact that a structural break shifted the american demand for money shortly after 1973 it is difficult to pinpoint the source of the trouble precisely let alone to explain the event with an econometric model in their survey judd and scadding 1982 tentatively concluded that financial innovation is the source of the problem while this conclusion has not been universally accepted the instability of the money demand function is largely taken as a given stylized fact the primary goal of this article is to provide an alternative solution to the case of the missing money using the methods of hendry 1979 it should be stressed at the outset that as this paper deals with a problem in the applied literature it is unabashedly empirical in nature the paper attempts to explain an empirical difficulty without presenting a new theoretical model of money demand rather in the context of the standard transactions demand theory for narrow money a number of questions are analyzed with an atypical econometric model was there actually a shift or a series of shifts in the demand for money if not why have other investigators concluded that there was in fact a shift most importantly what function seems to be the most reasonable approximation to the data generation process during the period in question

a lagrange multiplier test of the restrictions for a simple rational expectations model the lagrange multiplier test of the restrictions for a simple but common class of rational expectations model is developed for these kinds of models the value of this test will never exceed the likelihood ratio the difference is usually small because monte carlo evidence suggests that it performs similarly to the likelihood ratio and wald tests in small samples however an economic example suggests that larger differences are possible

expectations of exchange rates and differential inflation rates further evidence on purchasing power parity in efficient markets the paper tests the null hypothesis of ex ante purchasing power parity the empirical evidence obtained is inconsistent with the null for major industrialized countries over the current floating exchange rate regime expected nominal exchange rate changes appear to deviate systematically from expected inflation rate differentials over the same holding period even though real exchange rate changes appear to be serially uncorrelated this supports the presence of time varying risk premia in foreign exchange markets and real determinants of exchange rate movements as suggested by equilibrium theories of international asset markets this paper tests the hypothesis that the expected change in the exchange rate of two countries equals the expected differential in their inflation rates over the same holding period this relationship is an ex ante version of the classical relative purchasing power parity ppp that holds under some versions of efficient foreign exchange and international commodity markets it has important implications for the efficacy of government policies in open economies and has been the focus of numerous empirical studies the ex ante ppp eppp differs from the traditional ppp proposed by cassel 4 in the explicit treatment of uncertainty as formulated by roll 32 the eppp is based on the constraint that in efficient markets the net return to speculators engaging in intertemporal speculation on goods in the foreign country is anticipated to be zero 1 an immediate implication of eppp is that innovations in real exchange rates or deviations from ppp follow a martingale process in sharp contrast to the well documented empirical rejections of the conventional ppp strong support for the martingale property of eppp exists in the literature 2 the proposition that the differences in the expected price relatives of two countries are exactly accounted for by the expected change in exchange rates over the same period is inconsistent with a number of theoretical observations in the extant literature in particular the eppp model assumes that the expected real interest rate differential between each pair of countries is intertemporally constant in order to rule out commodity and financial arbitrage in a world of

stability and non linear dynamics in the broad demand for money in spain in this article we estimate a money demand function for broad money in spain in the period 1978 1998 stability tests indicate the existence of a stable money demand function in the long but not in the short run using recent non linear techniques we find that such instabilities are caused by a non linear adjustment of real balances towards a stable long run equilibrium

the demand for money a dynamic rational expectations model macroeconomic modelling generally has widely adopted the use of forwardlooking variables in behavioural relationships studies of the demand for money being something of an exception the aim of this paper is to provide preliminary empirical results of a model which explicitly incorporates expectations of the future into the demand function for narrow money the approach adopted is the modelling of the demand for money within a multi period costs of adjustment framework under the assumption of rational expectations agents are assumed to pursue a target or long run level of money balances which is itself a function of prices income and interest rates this results in an empirical specification which consists of both backwardlooking and forward looking components the model is estimated using uk data for the period i963i i983iii the remainder of the paper is divided into four sections in section i we outline the framework in which our model is derived in the following section we discuss the econometric techniques used and in section iii we present our empirical results a final section concludes

the optimal quantity of money a reconciliation abstract despite the apparent disagreement of samuelson s 1958 overlapping generations model and townsend s 1980 turnpike model on the optimal quantity of money in both i those endowed at the start with goods prefer a constant money stock and ii those endowed at the start with fiat money prefer deflation

money demand instability expectations and policy regimes a note on the case of italy 1964 1986 abstract this paper compares the stability performance of feedback and feedforward specifications of the demand for m2 in italy over the period 1962 1986 a clear change in the monetary policy regime occurred in 1969 1970 together with marked breaks in the processes generating several relevant variables in the mid 70s making this period particularly appropriate for the investigation of the potential role of expectations our main results show that the feedback specification suffers from instability at both relevant dates whereas the feedforward specification is remarkably stable during the policy regime change but displays signs of instability during the mid 70s

forward looking price setting in uk manufacturing given an equilibrium pricing rule minimization of a multiperiod quadratic cost function yields a precise specification for the weights on the leads and lags of a dynamic pricing equation using an equilibrium cointegrating vector the theoretical specification is found to fit the u k manufacturing data remarkably well non nested tests fail to reject either the backward looking error correction or the forward looking model against the alternative so long as dynamic homogeneity is imposed in the error correction model this is consistent with the notion that the error correction model is conflating the true structural model which is forward looking with the expectation formation process copyright 1992 by royal economic society

instrumental variables procedures for estimating linear rational expectations models abstract this paper illustrates how to use instrumental variables procedures to estimate the parameters of a linear rational expectations model these procedures are appropriate when disturbances are serially correlated and the instrumental variables are not exogenous we compare our procedures to some alternative estimators that estimate free parameters from restrictions implied by the euler equations the procedures are applicable to a variety of linear rational expectations models several examples of which we cite

currency substitution and nonlinear error correction in taiwan s demand for broad money we modify the conventional money demand function by including a real exchange rate variable to reflect the effect of currency substitution empirical evidence indicates that the variable is crucial to the long run stability of taiwan s money demand after finding the failure of a linear error correction model ecm in describing the dynamics of taiwan s money demand we apply a nonlinear ecm to examine its dynamics and support the appropriateness of the nonlinear model empirically

generalized method of moments and macroeconomics we consider the contribution to the analysis of economic time series of the generalized method of moments estimator introduced by hansen we outline the theoretical contribution conduct a small scale literature survey and discuss some ongoing theoretical research

the computational experiment an econometric tool an economic experiment consists of the act of placing people in an environment desired by the experimenter who then records the time paths of their economic behavior performing experiments that use actual people at the level of national economies is obviously not practical but constructing a model economy and computing the economic behavior of the model s people is such experiments are termed computational this essay specifies the steps in designing a computational experiment to address some well posed quantitative question the authors emphasize that the computational experiment is an econometric tool used in the task of deriving the quantitative implications of theory

a re interpretation of the linear quadratic model when inventories and sales are polynomially cointegrated summary estimation of the linear quadratic model the workhorse of the inventory literature traditionally takes inventories and sales to be first difference stationary series and the ratio of the two variables to be stationary however these assumptions do not always match the properties of the data for the last two decades in the united states we propose a model that allows for the non stationary characteristics of the data using polynomial cointegration we show that the closed form solution has other recent models as special cases the resulting model performs well on aggregate and disaggregated data copyright 2006 john wiley sons ltd

identification and estimation of money demand in most natural sciences physics chemistry biology theories are validated by controlled experiment however in other natural sciences astronomy meteorology and in most social sciences including economics the data are characteristically generated not by experiment but by measurement of uncontrolled systems in economics theories take the form of restrictions on the models assumed to generate the data and statistical methods replace experimental controls in testing these restrictions and here is the difficulty in economics particularly macroeconomics the theory used to derive tests ordinarily does not generate a complete specification of which variables are to be held constant when statistical tests are performed on the relation between the dependent variable and the independent variables of primary interest accordingly in such cases there will be a set of often very different candidate regression based tests each of which has equal status with the others since each is based on a different projection of the same underlying multivariate model except in the unlikely event that the explanatory variables are mutually orthogonal the conditional regression coefficients which generally form the basis for the test statistic will depend on the conditioning set we conclude from this that if a theory which does not generate a complete specification of the regression test is nonetheless to have testable implications these implications must be robust over the permissible alternative specifications if the restrictions indicated by the theory are satisfied in some projections but not in others that have an equal claim to represent implications of the theory one cannot conclude that the theory has been confirmed the fact that the observable implications of valid theories must obtain over a broad but usually incompletely specified set of regressions rather than for a single regression introduces a large and unavoidable element of imprecision into hypothesis testing in macroeconomics generally it appears to be appropriate to weaken the statistical criterion for rejecting theories consider for example the theory of money demand which will engage our attention in this paper the tobin baumol square root formula implies that the elasticity of money demand with respect to the interest rate is exactly one half but which interest rate should wealth be held constant inflation in view of such uncertainties it would be inappropriate to insist in a literal minded fashion on rejecting the tobin baumol model if in some regression the measured interest elasticity differed from one half by more than two standard deviations and only then obviously a more flexible approach is called for the practice has been to conclude that the statistical evidence is consistent with the tobin baumol model as long as the interest rate coefficient is negative if it is negative and significant or negative and insignificantly different from minus one half that would provide somewhat stronger confirmation but a positive coefficient particularly a significantly positive coefficient would be viewed as raising questions about the validity of the theory in macroeconomics generally as in the money demand application the typical response to specification uncertainty has been to regard a theory as supported if the signs of the estimated coefficients agree with those expected from theory and as disconfirmed otherwise there is no theoretical justification for this procedure but it seems to be a reasonable course to follow the point that economic theory ordinarily generates incompletely specified statistical university of california santa barbara we have received helpful comments from andrew abel robert clower michael darby robert engle stephen goldfeld david laidler edward leamer robert lucas frederic mishkin and edward prescott thomas hall provided able research assistance

u s money demand structural shifts or heterogeneous agents this paper examines whether observed structural shifts in the money demand function could be the result of agent heterogeneity due to different household income levels following the methodology of stoker 1986 income distribution variables are found to be significant determinants of money demand and once changes in the distribution of income are accounted for there is no evidence of parameter instability a money demand function incorporating income distribution effects is shown to perform as well or better than several standard alternatives on the basis of diagnostic tests non nested hypothesis tests within sample prediction errors and out of sample forecasting

the long and short of money short run dynamics within a structural model empirical examinations into aggregate money demand functions generally incorporate a monetary aggregate as the dependent variable while this custom may be inefficient it does not create any new difficulties for estimating the demand function s long run parameters as money supply would equal money demand the short run estimates however are not as fortunate as the monetary aggregate is a measure of supply and not demand one needs to tease out the short run responses associated with money demand changes with those which are associated with monetary supply shocks the present article therefore proposes a more complete representation of monetary sector behaviour and in doing so finds significant support for the so called buffer stock money demand models

labor hoarding superior information and business cycle dynamics abstract in this paper we test whether a labor hoarding environment with basic and augmented laws of motion provide an adequate explanation for observed business cycle dynamics the basic law of motion assumes that the information set used by economic agents to forecast future forcing variables includes only the history of forcing variables augmented laws of motion assume that the information set is superior and include both forcing and hidden exogenous variables we show that the labor hoarding environment with the basic law of motion fails to replicate observed business cycle facts while the environment with augmented laws of motion successfully matches these facts

convergence rates to purchasing power parity for traded and nontraded goods this article estimates the speed of the adjustment coefficient in structural error correction models we use a system method for real exchange rates of traded and nontraded goods by combining a single equation method with hansen and sargent s instrumental variables methods for linear rational expectations models we apply these methods to a modified version of mussa s model our results show that the half lives of purchasing power parity deviations for the rates of traded goods are less than 1 year and are shorter than those for general price and for nontraded goods in most cases implying a faster adjustment speed to parity

the dynamic effects of aggregate demand and supply disturbances we interpret fluctuations in gnp and unemployment as due to two types of disturbances disturbances that have a permanent effect on output and disturbances that do not we interpret the first as supply disturbances the second as demand disturbances demand disturbances have a hump shaped mirror image effect on output and unemployment the effect of supply disturbances on output increases steadily over time peaking after two years and reaching a plateau after five years

vector rational error correction abstract systems of forward looking linear decision rules can be formulated as vector rational error correction models the closed form solution of the restricted error corrections is derived and a full information estimator is suggested the error correction format indicates that the assumptions of convex adjustment costs and rational expectations impose different types of a priori restrictions on the dynamic structure of the error corrections an empirical model of the producer decision rule for capital investment illustrates that the data rejects dynamic restrictions imposed by a standard model of adjustment costs but supports a more general description of convex frictions

a new approach for estimating and testing the linear quadratic adjustment cost model under rational expectations and i 1 variables abstract in this paper we propose a simple method for estimating and testing the linear quadratic adjustment cost lqac model in the presence of i 1 processes we specify the lqac model as an exact rational expectations model and we assume that the dgp for the observable variables belongs to the class of cointegrated error correction ecm models by deriving the restrictions implied by the lqac model on the parameters of the ecm we propose an alternative econometric technique for the lqac model in contrast to existing procedures we explicitly account for situations where the cointegration rank of the ecm is greater than the number of control variables i e one the method is applied to the demand for labor in denmark

microfoundations for a stable demand for money function scientific revolutions seldom occur when the prevailing theories appear to be performing well it is only when the accepted theory fails to offer a satisfactory explanation of events that new and more robust theories are proposed of these new theories the one which can explain the successful performance of the previous theory and also the events which led to its demise becomes the replacement so it is in the history of modern monetary economics the failure of the partial adjustment model in the mid s is well documented in the united kingdom and the united states and the search for a replacement has been the main point on the agenda since that time there are many contending theories some of which are advocated by the other contributors to this controversy but the mark of a truly better theory which can be claimed to supersede the partial adjustment model is one that can explain the success and the breakdown of the previous theory as well as the events subsequently central to the argument of this paper is the importance of individual behaviour in the context of a market for monetary assets only by means of careful investigation of the microeconomic behaviour underpinning monetary economics at the individual and the market level can the stability of the money demand function be restored it is the purpose of this paper to suggest that the buffer stock approach has gone further than other approaches in dealing with the fundamental micro foundations of the demand for money it does not suggest that other approaches have no microfoundations but they tend to concentrate exclusively on specific aspects of the micro structure such as separability and ignore others relating to the behaviour of individual optimisers in a monetary market the buffer stock model has firm micro foundations which can explain the events both before and after the breakdown of the partial adjustment model section i provides an historical background to the debate and section ii gives a brief overview of buffer stock models which shows that unlike other approaches they have been able to reconcile the past success of the partial adjustment model with its present failure the nature of the microfoundations of buffer stock models are the source of the success and are discussed in more detail in section iii the final section evaluates the buffer stock approach in the light of the other alternatives

the linear quadratic adjustment cost model and the demand for labour in this paper we demonstrate a new way of testing the linear quadratic adjustment cost lqac model under rational expectations we illustrate how the parameter restrictions arising from this model can be formally specified and we use these restrictions to extent the technique of campbell and shiller 1987 to a wider class of models based on present value relations potentially the demand for labour is an area in which the lqac model can find applicability in practice and subsequently we analyse sectoral labour demand in danish manufacturing we find however that for our data set the quadratic adjustment cost model under rational expectations can be rejected

an econometric analysis of fluctuations in aggregate labor supply and demand the paper contains a simple equilibrium model of the labor market the supply function allows for intertemporal substitution in response to real wage fluctuations and the demand function allows for adjustment costs on employment the supply and demand functions both solve quadratic partial adjustment problems driven by rational expectations about future real wages the market equilibrium also solves a partial adjustment problem driven by rational expectations about future preference and technology shocks two related issues are emphasized the identification of dynamic labor supply and demand functions and the theoretical interpretation of serial correlation in employment and real wages when the supply and demand shocks are assumed to be ar 1 processes which are not causally related the model delivers a simple structure for the equilibrium process for employment and real wages which is a restricted var 2 this simple structure facilitates the interpretation of summary statistics on the time series properties of observed employment and real wage series the supply and demand functions can both be locally identified using only employment and real wage data an illustrative application is presented using u s manufacturing data for the period 1948 1971

regional trade agreements versus global trade liberalisation implications for a small island developing state this study undertakes an empirical investigation of the macroeconomic and sectoral impacts of two forms of regional trade agreements vis a vis global trade liberalisation on a small island country using fiji as a case study in order to capture the feedback effects of such a complex set of policies we employ a dynamic computable general equilibrium model of the fijian economy to investigate i the impact of the pacific island countries trade agreement picta ii the impact of picta the pacific agreement for closer economic relations pacer and the economic partnership agreements epas iii the impact of full tariff liberalisation i e tariff removal only and iv the impact of full trade liberalisation with removal of both tariff and non tariff barriers while picta consistently provides the least benefits across a range of macroeconomic indicators including real output welfare trade volumes and employment full trade liberalisation involving the removal of tariff and non tariff barriers provides the greatest benefits compared to the other scenarios in terms of real output however the latter scenario is outperformed by picta pacer the epas and full tariff liberalisation in terms of welfare effects trade volumes and employment the policy implications hold important lessons for developing countries considering trade liberalisation

a theoretical derivation of the functional form of short run money holdings this paper considers the short run adjustment of money holdings towards their desired levels a rationale for short run money holdings is given which allows for uncertainty in cash flows and it is shown how the adjustment to desired money balances will occur following a change in some of the economic variables the model generates a particular form for the short run demand for money function which is shown to be econometrically superior to the standard ad hoc formulation the chief theoretical novelty is the derivation of the appropriate transient probability density of money holdings

microfoundations and the demand for money the reader should note that i write this piece in a style that aims to be accessible to that much neglected representative agent the woman on the eurostar train hence unlike the man on the clapham omnibus i assume my intrepid traveller has reasonable knowledge of monetary economics and econometrics but not of the details of the demand for money space constraints force me to indulge in a certain amount of poetic licence but i hope this results in poetic justice there have been many wars fought on this particular battlefield some with almost religious zeal on the theoretical side of the debate we sometimes have the equivalent of religious fundamentalists be they muslims jews christians etc who would dismiss almost any evidence unless it were associated with a strong microtheoretic basis as laid down in the koran talmud or bible the empirical side encompasses agnostics atheists as well as born again econometricians pure theorists inhabit the sunlit uplands while applied economists and policymakers flounder in the muddy plain below occasionally gaining solace from their copy of zen and the art of motorcycle maintenance in general in economics we do not have the luxury of controlled experiments as is the case in the natural sciences what distinguishes good microfoundations from bad and how to weight priors and statistical evidence is subject to much dispute leamer i983 hendry et al i990 as in religion sometimes there is the occasional miracle proclaimed after a suitable interval a new saint may be declared and disciples flock to the new shrine later doubts may arise as to whether a miracle really did occur human behaviour is difficult to explain let alone predict so the search for the equivalent of the holy grail ark of the covenant etc is bound to be arduous in scholarly journals we generally read of the success of the demand for money like diplomats who are sent abroad to lie for the good of their country publication may require applied economists to be somewhat economical with the actualite lovell i983 leamer i983 in this article i want to be as honest as possible about our success and failures in this area the prior information an armchair economist would consider when thinking about the demand for money over the past 40 years in western industrialised countries which have experienced moderate inflation might

an econometric analysis of u s vital wheat gluten imports abstract in light of the wheat wet milling industry s development in the e c and of the prominent role u s imports play in the international market for wheat gluten this paper discusses the international market for wheat gluten an important component of processed grain products an econometric analysis of the u s import demand for wheat gluten is undertaken the price of flour income and the u s value of wheat protein are found to be important determinants of wheat gluten imports

an investigation of the determinants of manufacturing employment in the united kingdom in this paper we present and estimate an adjustment cost model of industry employment which takes explicit account of both expectations and aggregation over different labour types the resulting model is subject to a large number of tests and is a highly robust representation of the data finally forecasts are produced for manufacturing employment up to 1990

us business credit sources demand deposits and the missing money abstract this study accounts for much of the missing money in the us through compensating balances business lending by banks affects demand deposit growth standard money demand models include variables that likely pick up income and interest rate effects on the transactions demand for demand deposits and on compensating balance requirements provided that bank lending to firms is stable however during the missing money period business shifted toward nonbank sources of short term credit causing a decline in compensating balances empirical finding support this hypothesis as a partial explanation for the missing money using the federal reserve board s demand deposit model

welfare impacts of import controls on botswana s horticulture botswana has for the past two decades used import controls permits to regulate horticultural imports and thereby promote economic diversification through import substitution this article estimates import demand equations to capture the impact of import controls on horticultural imports oranges potatoes and onions into botswana using data for 1974 to 2001 parameter estimates are used to compute nominal protection rates nprs and welfare effects model generated nprs are estimated at 191 75 and 109 for oranges potatoes and onions respectively imports of oranges potatoes and onions declined by 32 29 and 35 respectively due to the implementation of import controls over time consumer losses and quota rents rose while producer gains declined net social losses also increased implying that import controls became increasingly burdensome it is argued that import controls have not been very effective in promoting import substitution the study is important for the trade liberalization debate in the southern african customs union sacu and within the southern african development community sadc where import permits and other nontariff barriers are pervasive have proliferated and are a major hindrance to intraregional trade

aggregate employment real business cycles and superior information abstract we test whether dynamic stochastic general equilibrium artificial economies associated with several labor market structures provide an adequate characterization of aggregate employment volatility and dynamics our test is robust to possible misspecifications about the information set used by economic agents to forecast future events accounting for agents superior information we find that the divisible labor indivisible labor labor adjustment costs and labor hoarding structures replicate employment volatility in contrast to the nominal wage contracts structure also the labor hoarding structure provides a substantially better account of employment dynamics

on the european responsibility in the agricultural multilateral trade negotiations modelling the impacts of the common agricultural policy the present round of multilateral trade negotiations is still deadlocked over agricultural trade the european union eu is urged by its trading partners to open its agricultural markets economic evaluations of trade liberalisation scenarios unanimously conclude that a substantial opening of agricultural markets is required for a successful welfare improving doha round in this paper we perform new evaluations to identify precisely the contributions of the european farm policy and to examine the robustness of these evaluations in the representation of this complex policy using the same specifications as in major previous studies our first simulations show that the eu has a major responsibility in delivering significant gains to the developing countries on the other hand when we conduct the same experiments with a more relevant calibration and modelling of the european farm policy instruments the gains that these developing countries may reap from the eu liberalisation are considerably reduced accordingly the current charge against the eu is simply inopportune

adjustment costs durables and aggregate consumption abstract previous tests of the permanent income hypothesis pih have focused on either non durables or durables expenditures in isolation this paper studies consumer purchases of non durables and durables as the outcome of a single optimization problem it is shown that with non separability in utility the presence of adjustment costs of changing durables stocks may affect the time series properties of both components of expenditure an econometric test of the pih based on the model developed in the paper is both more efficient and less prone to bias than those in some previous studies however this test confirms earlier rejections of the pih in aggregate quarterly data

are trade preferences more effective than aid in supporting exports evidence from the everything but arms preference scheme this study examines the effect of the everything but arms eba trade preferences regime on exports from african caribbean and pacific countries acp to the european union eu with this aim an augmented gravity model is estimated for exports from the 79 acp countries to the eu 15 for the time period 1995 to 2005 using panel data techniques the model estimates are used to quantify the effect of the eba preferences on the acp ldcs export performance and to compare it with the impact of official development assistance in addition to their separate effects the combined impact of eba and aid flows is examined the main results do not confirm a positive effect of the eba regime on exports otherwise the combined effect of eba and aid on exports is positive supporting an eu development strategy that includes both sorts of assistance aid and trade preferences

price and income elasticities of disaggregated import demand results from uecms and an application this paper presents an empirical analysis of the demand for maize milk powder butter and rice imports in cyprus using annual time series data covering the period 1975 1994 none of these products is produced in cyprus and all the necessary quantities are imported to meet domestic demand the primary objective of the paper is to derive long run price and income elasticities of import demand that can be used to analyse the impact of various policies such as the adoption of the common agricultural policy cap when and if the republic of cyprus joins the european union eu in so doing the paper takes on board some recent developments in time series econometrics the cointegration test used the bounds test is a recent test and is based on the estimation of an unrestricted error correction model uecm parsimonious models were derived using hendry s general to specific approach the estimated elasticities were subsequently used to quantify some of the implications for cyprus had the cap been ope

an econometric model of canadian monetary policy over the 1970s the last decade has witnessed the emergence of the bank of canada as a key participant in the arena of policy formation indeed the high profile of the governor and the bank has given rise to a considerable amount of discussion and debate over canadian monetary policy in both the popular media and academic journals i to a large extent this analysis has been essentially descriptive being based upon casual observations rather than a tightly formulated econometric model from the viewpoint of understanding the canadian economy over the 1970s there is a growing need to establish empirically the mechanisms of monetary policy in canada and to determine its impact upon such macroeconomic variables as real output the purpose of this paper is to specify and to estimate a simple model of canadian monetary policy over the seventies the model s focus is upon several prominent institutional details that are special to the operation of canadian monetary policy accordingly the model reflects the practice of the bank of canada in setting nominal interest rates and allowing the nominal money supply to be demand determined this modeling necessarily leads to an examination of the role and effects of the money targets adopted by the bank of canada since 1975

unemployment in britain male unemployment in britain has risen from around 2 per cent in the 1950s to around 17 per cent in 1985 see figure 1 the figures are for male unemployment because there is no consistent series for women 1 even more remarkably unemployment has fallen in only three years out of the last twenty 1973 1978 and 1979 to account for this we need a model that explains both changes in the natural or non accelerating inflation rate of unemployment nairu and deviations from it we use a three equation supply side model centred on the labour market this has two main features the first concerns the determination of employment in the short run the labour demand function that we use cuts through the fruitless debate now raging especially in europe as to whether current unemployment is classical or keynesian according to the classical view employment is too high because real wages are too high according to the keynesian view real wages are not binding and unemployment is high because the product market does not clear with prices too high relative to nominal demand the whole debate is set in the framework of perfect competition yet in perfect competition prices are set by impersonal forces and it is not clear what could possibly stop prices clearing the market it is much more reasonable to think of prices as being set by imperfectly competitive firms existing prices being the best they can think of given the demand they face in this context firms demand for labour will depend on both the real product wage and the level of real aggregate demand this is the demand function we estimate and it conforms both to common sense and to the data however this does not imply that employment can be made to grow without limit by pumping up real demand for in the medium term when price surprises are eliminated our model determines three variables employment real wages and real demand on the basis of three equations an employment equation a price equation and a wage equation thus in the medium term there is a natural level of employment and corresponding to this a natural level of real aggregate demand the second key feature of our model concerns the medium term determination of unemployment in the medium term the planned mark up of wages over prices in wage settlements must be consistent with the mark up of prices over wage costs in employers pricing behaviour for if wage setters try to set real product wages higher than is consistent with employers pricing behaviour this generates ever increasing inflation thus the key to understanding unemployment in the medium term is the behaviour of wage setters if events occur that push them towards too high real wages then unemployment has to rise to offset these influences we shall call these influences wage pressure variables or push factors and they are clearly crucial in understanding unemployment the variables here include the social security system employment protection

manufacturing stocks and forward looking expectations in the uk this paper derives a model of the stocks plan based on optimal behavior by the firm when facing adjustment costs with forward looking expectations formation estimates of the model are reported for manufacturing using three alternative expectations mechanisms for determining expected sales time series published forecasts derived from national institute published forecasts and rational expectations the latter uses a submodel dependent on weakly exogenous variables single equation and whole model comparisons are made of the stocks equation estimated with forward expectations versus a traditional backward looking model these favor the forward looking model copyright 1986 by the review of economic studies limited

the search for a stable money demand function a survey of the post 1973 literature phe question of whether the demnand function for money is stable is one of the most important recurring issues in the theory and application of macroeconomic policy what is being sought in a stable demand function is a set of necessary conditions for money to exert a predictable influence on the economy so that the central bank s control of the money supply can be a useful instrument of economic policy as such the notion of a stable demand function appears to involve three key elements e g john t boorman 1976 p 317 and david e w laidler 1977 pp 34 35 first the demand for money relation should be highly predictable in a statistical sense as measured by the usual goodness of fit statistics precision of estimated coefficients and presumably its ability to forecast accurately out of sample second a stable demand function for money has relatively few arguments a relationship that requires knowledge about a large number of variables in order to pin it down is in effect not predictable finally the variables that appear as arguments in the function should represent significant links to spending and economic activity in the real sector in sum a stable demand function for money means that the quantity of money is predictably related to a small set of key variables linking money to the real sector of the economy the importance of a stable money demand function for monetary policy can be illustrated with the standard is lm model in which interest rates and gnp are the endogenous variables in this context a stable demand function for money translates into a well defined relationship between money interest rates and gnp

interrelated factor demands from dynamic cost functions an application to the non energy business sector of the uk economy in this paper we propose a dynamic cost function which allows us consistently to derive a set of dynamic interrelated factor demand equations in the general error correction form introduced by anderson and blundell 1982 this paper expands results recently published in urga 1996 it shows that the derivation of an effective underlying cost function allows us to identify the full set of parameters of the underlying process this does not happen in the standard anderson blundell formulation we report an empirical exercise used to model the so called supply side of the london busines school large scale economic model where we estimate both the set of factor demands and the underlying dynamic cost function for the non energy business sector of the uk economy

agricultural liberalisation and the least developed countries six fallacies today agriculture remains the most distorted sector of the world economy therefore agricultural liberalization in the doha negotiations is rightly the top priority but the public policy discourse on the subject remains fogged by a number of fallacies these fallacies probably originated with the leadership of the world bank but have now been embraced by the imf oecd oxfam and the leading academic critics of globalization the paper identifies six fallacies and offers evidence and analysis to debunk them 1 agricultural border protection and subsidies are largely a developedcountry phenomenon 2 developed country agricultural subsidies and protection hurt the poorest developing countries most 3 developed country subsidies and protection hurt the poor rural households in the poorest countries 4 developed country agricultural protection and subsidies constitute the principal barrier to the development of the poorest developing countries 5 agricultural protection reflects double standard and hypocrisy on the part of the developed countries 6 what the donor countries give with one hand aid they take away with the other farm subsidies

rational expectations in stationary linear models linear time series models have come to dominate the macroeconomic literature on rational expectations and equilibrium business cycle theory but the explicit solution of such models has generally required strong restrictions upon the exogenous process of stochastic shocks e g temporal independence as well as upon the values of various demand and supply elasticities this paper exhibits a solution technique the method of z transforms which does not require one to impose such restrictions the value of this method is illustrated by applying it to completely characterize the symmetric stationary rational expectations equilibria of a naive linear model of land speculation this approach also permits systematic study of the informationally asymmetric equilibria of the model this paper develops a method for analyzing rational expectations re equilibria in linear economic models the methods i shall discuss usually enable one to determine whether or not a given model has a re equilibrium and if one exists to exhibit an explicit expression for the stochastic process of equilibrium prices the techniques apply to linear models driven by stationary processes of exogenous random shocks

estimating long run economic equilibria with stochastic trends an asymptotic theory is provided to analyze a menu of currently existing estimators of cointegrated systems we study in detail the single equation ecm seecm approach of hendry our theoretical results lead to prescriptions for empirical work such as specifying seecm s nonlinearly and including lagged equilibrium relationships rather than lagged differences of the dependent variable as covariates simulations support these prescriptions and point to problems of overfitting not encountered in the semiparametric approach of phillips and hansen 1990

the role of money supply shocks in the short run demand for money abstract previous money demand models are either inconsistent with contemporaneous adjustment of the price level to expected changes in the nominal money supply or imply implausible interest rate fluctuations in response to innovations in nominal money we propose a shock absorber money demand model in which money supply shocks affect the synchronization of asset transactions and so engender a temporary increase or decrease in desired money holdings expected changes do not engender such fluctuations in real money inventories in simultaneous estimates for eight industrial countries the shock absorber model proved empirically superior

nonlinear equilibrium correction in u s real money balances 1869 1997 several theoretical models of money demand imply nonlinear functional forms for the aggregate demand for money characterized by smooth adjustment toward long run equilibrium in this paper we propose a nonlinear equilibrium correction model of u s money demand that is shown to be stable over the sample period from 1869 to 1997

manufacturing stocks expectations risk and co integration the modelling of firms inventory behaviour has been plagued by structural instability and despite a great deal of research effort over recent years little headway has yet been made in producing a structurally stable model of stock levels wallis et al i987 surveyed the main uk models of inventory behaviour and concluded that the tests of predictive failure are particularly powerful when conducted over periods in which data characteristics change and over half the equations we consider are rejected on the basis of their predictive performance in the early i980s this is a surprising result since the poor performance of their predecessors over this period was a prime motivation for the research that has led to the current specifications the similarity in turning points in the forecast errors both for the aggregate stockbuilding equations and for the different categories of stocks suggests the omission of some factor s common to all specifications wallis et al i987 p 144 their analysis was conducted using within sample stability tests and more recent data would undoubtedly find an even higher rejection rate accordingly this paper seeks to identify important omitted components or misspecification in the existing models of inventory behaviour in response to the suggestion in the last sentence of the wallis et al quotation we take as our point of departure a number of recent papers on company sector behaviour which have focused on intertemporal optimisation under rational expectations the seminal work of sargent 1978 on the demand for labour has been followed by a number of studies which seek to treat the firms expectations of future variables in an explicit way this work includes nickell 1 984 and henry and wren lewis i 984 on the labour market and hall et al i986 on the determination of stock levels one common finding amongst these and many other papers is that of a root in the dynamic process under consideration which is close to unity this means that the long run solution for the model is poorly determined and this finding is a cause for some concern recently with the growth of the literature on cointegration see engle and granger 1987 hall i986 this finding takes on an even more serious aspect since a symptom of non cointegration is the lack of a well defined long run solution so the finding of a near unit root may be indicative that earlier researchers were in fact working with sets of variables which failed to cointegrate which would inevitably lead to spurious regression problems in the sense of granger and newbold i 974

expected life time utility and hedging demands in a partially observable economy this paper analyzes the expected life time utility and the hedging demands in an exchange only representative agent general equilibrium under incomplete information we derive an expression for the investor s expected life time utility and analyze his hedging demands for intertemporal changes in the stochastic unobservable growth of the endowment process and the changing quality of information regarding these changes the hedging demands consist of two components which could work in opposite directions so that a conservative consumer may end up having positive hedging demands our results are qualitatively different from those prevailing under constant growth cf brennan m j 1998 the role of learning in dynamic portfolio decisions european finance review 1 295 306 ziegler a 2003 incomplete information and heterogeneous beliefs in continuous time finance springer berlin chapter 2

the buffer stock notion in monetary economics not the least of harry johnson s contributions to our discipline was the series of survey papers on aspects of monetary economics which he produced during the 1960s and 1970s it is no exaggeration to say that the way in which the literature of monetary economics is organised even now follows the design which johnson first set out in 1962 and built on in the subsequent decade nevertheless the subject has not stood still and one of the more interesting developments of the last few years has involved the introduction of what has been variously described as the disequilibrium money shock absorber or as i prefer to call it the buffer stock notion into monetary economics the development of this line of thought was getting underway before johnson s untimely death much of it indeed under the auspices of his own research programme at the lse even so this did not happen early enough for the relevant ideas to be put in their proper niche by johnson himself and the buffer stock approach is not yet fully integrated into the mainstream of monetary economics much of the relevant literature is empirical concerned with modelling particular aspects of the monetary experience of specific countries hence it is fragmented and contains few papers which attempt a coherent account of just what this approach is and how it relates to other approaches to monetary analysis although essays by goodhart 1982a b and judd and scadding 1982a contain important discussions of these issues to the best of my knowledge only jonson 1976a and knoester 1979a have devoted entire papers solely to this central issue and these are relatively inaccessible and hence less widely known than they deserve to be in this lecture i shall attempt to give a brief account of the essentials of this approach first i shall sketch out its microeconomic background and then i shall discuss those theoretical characteristics which differentiate it from the neo austrian analysis of robert e lucas jr and his associates as well as from the conventional keynesian approach to monetary economics last but by no means least i shall argue that it yields simple theoretical insights into important empirical and policy related issues which are troublesome for alternative approaches in short my tribute to harry

a re examination of the q theory of investment using u s firm data investment models based on tobin s q are theoretically appealing but they have been an empirical disappointment when applied to aggregate time series data this paper explores two potential explanations for the poor empirical performance of q investment models problems arising from aggregation and imperfect competition the results suggest that aggregation is responsible for spurious evidence of dynamic misspecification and at least partially responsible for an upward bias in estimated adjustment costs the evidence also suggests that imperfect competition in output markets may have an effect on the investment behaviour of some firms