will tighter futures price limits decrease hedge effectiveness abstract the events triggered by the global financial crisis gfc have led to calls for the regulation of financial markets given that regulation may involve opportunity costs this paper examines whether tighter futures price limits can reduce the effectiveness of a futures hedge we propose a new model that uncovers the underlying spot futures dynamics when futures prices are subject to limits we use the model to determine the maximum number of limit days that can occur before minimum variance hedging outcomes are adversely affected application of this model to the us soybean and corn markets reveals that existing limits do not reduce hedge effectiveness if the frequency of limit days increases from current levels of 1 to approximately 3 4 conventional hedging approaches will experience economically and statistically significant increases in portfolio variance these results are important for hedgers clearing houses and regulators in light of the recent calls for derivatives regulation

some empirical evidence on the effects of shocks to monetary policy on exchange rates this paper investigates the effects of shocks to u s monetary policy on exchange rates we consider three measures of these shocks orthogonalized shocks to the federal funds rate orthogonalized shocks to the ratio of nonborrowed to total reserves and changes in the romer and romer index of monetary policy in sharp contrast to the literature we find substantial evidence of a link between monetary policy and exchange rates specifically according to our results a contractionary shock to u s monetary policy leads to i persistent significant appreciations in u s nominal and real exchange rates and ii significant persistent deviations from uncovered interest rate parity in favor of u s interest rates

a conditional variance tale from an emerging economy s freely floating exchange rate this article studies daily return and volatility dynamics in the exchange rate of an emerging market economy turkey over the recent floating period we use generalized autoregressive conditional heteroscedastic garch and fractionally integrated garch figarch models with various error distributions findings show that a parsimonious figarch model with an asymmetric error distribution characterizes the daily turkish lira tl returns against us dollar and euro considerably well we find statistically significant asymmetry and peakedness in conditional returns and time varying volatility with long range dependence in conditional volatility long memory finding is robust to different specifications for the conditional returns as well as possible shifts in the return and volatility dynamics over sub periods results in the article show that despite the decline in volatility over the course of the recent float tl returns are still wild compared to developed economies exchange rates during the same period

heterogeneous information arrivals and return volatility dynamics uncovering the long run in high frequency returns recent empirical evidence suggests that the interdaily volatility clustering for most speculative returns are best characterized by a slowly mean reverting fractionally integrated process meanwhile much shorter lived volatility dynamics are typically observed with high frequency intradaily returns the present article demonstrates that by interpreting the volatility as a mixture of numerous heterogeneous short run information arrivals the observed volatility process may exhibit long run dependence as such the long memory characteristics constitute an intrinsic feature of the return generating process rather than the manifestation of occasional structural shifts these ideas are confirmed by our analysis of a one year time series of fiveminute deutschemark u s dollar exchange rates among the most puzzling issues is the behavior of volatility while the general properties of volatility remain elusive perhaps the most intriguing feature revealed by empirical work on volatility is its long persistence such behavior has sparked a search almost akin to that for the holy grail for the perfect garch model but the underlying question of why such volatility persistence endures remains unanswered we conjecture that the ability to analyze higher frequency data may be particularly useful in pursuing this issue goodhart and o hara 1997 the pronounced volatility clustering is arguably one of the most striking features of financial price series recorded at daily or weekly intervals and a large body of literature seeking to characterize this aspect of speculative returns has emerged over the past decade 1 at the same time convincing theoretical explanations for the underlying sources of long run persistence in volatility remain elusive the recent advent of comprehensive high frequency andersen is from the j l kellogg graduate school of management of northwestern university bollerslev is from the university of virginia and is a research associate at the national bureau of economic research we gratefully acknowledge the financial support provided by a research grant from the institute for quantitative research in finance the q group special thanks are due to olsen and associates for making the intradaily exchange rate quotes and reuter s news tape available we have received valuable comments from wake epps clive w j granger stephen f gray j huston mcculloch as well as seminar participants at the december 1996 triangle econometrics workshop the 1997 afa meetings in new orleans academia sinica the wharton school usc and georgetown and york universities we remain fully responsible for the content 1 see bollerslev chou and kroner 1992 for a survey of this literature using arch type

sticky prices and volatile output abstract we examine the effect of introducing a specific type of price stickiness into a stochastic growth model subject to a cash in advance constraint as in previous studies we find the introduction of price rigidities provides a substantial source of monetary non neutrality which contributes significantly to output volatility we show that the introduction of this form of sticky prices improves the model s performance at explaining inflation but worsens it for output the most dramatic failure of the model is the extremely high frequency fluctuations in output that it generates sticky prices not only fail to produce persistent business cycle fluctuations but they generate extreme volatility at very high frequencies

structural breaks and garch models of exchange rate volatility we investigate the empirical relevance of structural breaks for garch models of exchange rate volatility using both in sample and out of sample tests we find significant evidence of structural breaks in the unconditional variance of seven of eight us dollar exchange rate return series over the 1980 2005 period implying unstable garch processes for these exchange rates and garch 1 1 parameter estimates often vary substantially across the subsamples defined by the structural breaks we also find that it almost always pays to allow for structural breaks when forecasting exchange rate return volatility in real time combining forecasts from different models that accommodate structural breaks in volatility in various ways appears to offer a reliable method for improving volatility forecast accuracy given the uncertainty surrounding the timing and size of the structural breaks copyright 2008 john wiley sons ltd

can the new open economy macroeconomic model explain exchange rate fluctuations abstract this paper explores the successes and failures of the new open economy macroeconomics more critically by addressing the performance of the model at all frequencies along the line of watson s watson m w 1993 measures of fit for calibrated models journal of political economy 101 1011 1041 measures of fit this paper shows that the noem model with either pcp or ptm is not successful in generating the spectral density of the selected variables calculated from the data in particular the model cannot generate mass spectra of the exchange rates at low frequencies as in the data it shows that the noem model with either separable preference or incomplete asset market cannot generate the typical hump shaped spectra of exchange rates

valuation of power options under heston s stochastic volatility model abstract we derive semi analytic solutions for power option prices under the heston model specifically the pricing formula is shown to be valid whenever the power of the underlying asset price has a finite moment unlike the majority of stochastic volatility models there remains a significant problem to check the existence of moments of assets prices of order higher than one fortunately the moment explosion property under the heston model is examined systematically in andersen and piterbarg 2000 incorporating with their results we present explicit formulas for moment generating function of log price and for power option prices under the circumstances when the corresponding moments are finite in case that the corresponding moment explodes we provide two numerical methods to derive prices of power put and capped power call options in spite of a simple idea numerical examples show that the approximations are extremely accurate and efficient

dynamically consistent oil import tariffs the standard solution of the open loop optimal import tariff is normally time inconsistent the paper shows why and derives the dynamically consistent markov perfect tariff the two tariffs are compared they differ except for a special class of import demands the time paths of tariffs and the welfare cost of an inability to commit are calculated for a dominant importer the welfare costs of the inability to commit are small if its market share

nominal price rigidity money supply endogeneity and business cycles abstract this paper investigates the ability of nominal price rigidity to explain the co movement of inflation with the cyclical component of output observed in the post war u s data a dynamic general equilibrium model is constructed with the introduction of monopolistic competition and nominal price rigidity in a standard real business cycle model allowing for an endogenous money supply rule it is then demonstrated that sticky price models can explain the observed associations between movements in inflation and output much better than flexible price models this result depends little on whether money supply is assumed to be endogenous or not

time consistent export quotas in an oligopolistic world market abstract we investigate the strategic behavior between exporting countries that face endogenous terms of trade on the world market in a non cooperative setting if production decisions occur before consumption decisions the ex ante optimal export quota is not time consistent as the ex post elasticity of the residual foreign import demand curve is lower than the ex ante elasticity however we show that the exporters inability to irrevocably commit to their quota may be welfare superior to the precommitment solution if exporters can sell forward a proportion of their exports before production decisions are made they will do so even though in equilibrium it may decrease welfare compared to a situation in which forward markets do not exist moreover the equilibrium with forward markets is welfare inferior to the commitment equilibrium for exporters

nonstationarities in stock returns the paper outlines a methodology for analyzing daily stock returns that relinquishes the assumption of global stationarity giving up this common working hypothesis reflects our belief that fundamental features of the financial markets are continuously and significantly changing our approach approximates the nonstationary data locally by stationary models the methodology is applied to the s p 500 series of returns covering a period of over seventy years of market activity we find most of the dynamics of this time series to be concentrated in shifts of the unconditional variance the forecasts based on our nonstationary unconditional modeling were found to be superior to those obtained in a stationary long memory framework and to those based on a stationary garch 1 1 data generating process

modeling long memory and structural breaks in conditional variances an adaptive figarch approach this paper introduces a new long memory volatility process denoted by adaptive figarch or a figarch which is designed to account for both long memory and structural change in the conditional variance process structural change is modeled by allowing the intercept to follow a slowly varying function speci ed by gallant 1984 s exible functional form a monte carlo study nds that the a figarch model outperforms the standard figarch model when structural change is present and performs at least as well in the absence of structural instability an empirical application to stock market volatility is also included to illustrate the usefulness of the technique

long range dependence in an emerging stock market s sectors volatility modelling and var forecasting abstractthis study evaluates the sector risk of the qatar stock exchange qse a recently upgraded emerging stock market using value at risk models for the 7 january 2007 18 october 2015 period after providing evidence for true long memory in volatility using the log likelihood profile test of qu and splitting the sample and dth differentiation tests of shimotsu we compare the figarch hygarch and fiaparch models under normal student t and skewed t innovation distributions based on in and out of sample var forecasts the empirical results show that the skewed student t figarch model generates the most accurate prediction of one day var forecasts the policy implications for portfolio managers are also discussed

labor adjustment and gradual reform when is commitment important we analyze a model in which a government uses a second best policy to affect the reallocation of labor following a change in relative prices we consider two extreme cases in which the government has either unlimited or negligible ability to commit to future actions we discuss the factors that determine the importance of commitment ability and provide numerical examples the degree of commitment ability can alter the equilibrium policy both quantitatively and qualitatively in both extreme cases the dying sector is protected during the transition to a free market in order to decrease the amount of unemployment

last one out wins trade policy in an international exit game this paper examines the effect of intervention on the order and timing of exit in an international industry with fixed costs and declining demand a dynamic inconsistency problem arises when policymakers are unable to precommit they always intervene to prolong the life of the local firm even when this is not socially optimal the effect of tariff intervention is in all cases to terminate production prematurely and in many cases to reverse the order of exit intervention in the absence of recommitment is never first best and actually reduces welfare when the differential between firms fixed costs is large copyright 1994 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

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

noisy news and exchange rates a svar approach abstract this paper introduces noisy news shocks into a model of exchange rate determination to measure the impact of these shocks using a svar agents in the foreign exchange market make decisions with imperfect information about economic fundamentals driving interest rate differentials between countries in that they must rely on a noisy signal of future interest rates i apply the framework to the usd gbp nominal exchange rate for the period 1986 2013 results show that noisy news explains approximately one fifth of the forecast error variance in the nominal exchange rate with noise accounting for double 12 that of news 6 a historical decomposition of the exchange rate indicates that noise shocks are especially important during periods of changing monetary policy e g the 1990 easing and 2001 tightening of u s monetary policy and the unconventional monetary policies surrounding the financial crisis of 2008

analysing inflation by the fractionally integrated arfima garch model this paper considers the application of long memory processes to describing inflation for ten countries we implement a new procedure to obtain approximate maximum likelihood estimates of an arfima garch process which is fractionally integrated i d with a superimposed stationary arma component in its conditional mean additionally this long memory process is allowed to have garch type conditional heteroscedasticity on analysing monthly post world war ii cpi inflation for ten different countries we find strong evidence of long memory with mean reverting behaviour for all countries except japan which appears stationary for three high inflation economies there is evidence that the mean and volatility of inflation interact in a way that is consistent with the friedman hypothesis

volatility of stock market indexes an analysis based on semifar models by applying semifar models we examine long memory in the volatility of worldwide stock market indexes our analysis yields strong evidence of long memory in stock market volatility either in terms of stochastic long range dependence or in the form of deterministic trends in some cases both components are detected in the data thus at least partially there appears to be even stronger and more systematic long memory than suggested by a stationary model with long range dependence

long memory and persistence in aggregate output abstract we examine persistence in u s aggregate output by estimating fractionally integrated arima models these models provide better low frequency approximations to the wold representation than previous stochastic specifications and earlier results on the importance of a permanent component emerge as special cases we find evidence of long memory which induces persistence though this long memory need not be associated with a unit root our point estimates indicate that macroeconomic shocks while persistent are distinctly less persistent than many earlier studies suggest however confidence intervals associated with the long run response are quite wide

catching up with the joneses in a sticky price model this paper examines the effect of introducing external habit formation into calvo type and taylor type sticky price models the paper shows that external habit formation improves the performance of sticky price models in explaining the selected variables at nearly all frequencies while each model has diverse successes and failures the taylor type sticky price model seems to capture more closely the hump shaped spectra of the selected real variables of the data than the calvo type sticky price model

the role of gatt wto as a commitment device in the presence of a time lag free trade time consistent tariff policy and market size we consider whether a free trade policy is superior to tariff policies in the presence of a time lag between production and trade decisions we show that the preferable choice between a free trade policy and a time consistent tariff policy depends on the market size of the importing country however because a free trade policy itself is not necessarily credible in the presence of a time lag the importing country requires an international organisation such as gatt wto as a commitment device accordingly employing a non cooperative game approach we analyse under what conditions becoming a member of such an international organisation is a subgame perfect nash equilibrium and show that free trade under the gatt wto regime is pareto improving for the importing and exporting countries

explaining saving investment correlations national saving and investment rates are highly positively correlated in virtually all countries this is puzzling as it apparently implies a low degree of international capital mobility this paper shows that the observed positive correlation between national saving and investment rates arises naturally within a quantitatively restricted equilibrium model with perfect mobility of financial and physical capital the model is consistent with the fact that saving investment correlations are larger for larger countries but are still substantial for small countries further the model is consistent with the finding that current account deficits tend to be associated with investment booms copyright 1993 by american economic association

optimal tariffs on exhaustible resources we characterize the markov perfect equilibria of two games in which oligopsonistic importers of an exhaustible resource confront competitive suppliers who have rational expectations the games differ only in the timing of moves or the speed with which participants can adjust their plans the optimal tariff when sellers move first are less flexible differs considerably from that in which buyers move first and sellers retain more control over intertemporal arbitrage opportunities if the initial stock is small buyers suffer a disadvantage from being the first mover this is reversed if the stock is large

improving daily value at risk forecasts the relevance of short run volatility for regulatory quality assessment abstract in this paper we present a novel perspective on data filtering and present an innovative wavelet based approach that leads to improved value at risk var forecasts a separation of financial conditional volatility into short mid and long run components allows us to study the relevance of these frequency components with respect to a regulatory quality assessment for daily var forecasts a simulation study and an analysis of daily market prices suggest that short and mid run information components cover the relevant information that is necessary for estimating adequate daily var excluding long run information components reduces daily var forecasts by up to 4 and does not impact the quality of regulatory back testing

on the power of dickey fuller tests against fractional alternatives abstract we examine the properties of dickey fuller unit root tests under fractionally integrated alternatives and find that these tests have quite low power

on capturing oil rents with a national excise tax this paper argues that since the supply of oil in the ground is inelastic the incidence of a sales tax on oil maintained forever at a fixed rate would fall entirely on the oil suppliers in the world economy however the elasticity of supply of oil to a single country depends on that country s imports as a share of world output and on the elasticity of demand for that country the paper calculates optimal tax rates for a country as a function of these variables and estimates optimal oil tax rates for the u s for some oecd countries separately and for the u s plus the oecd collectively current u s tax rates are shown to be far below optimal values

domestic policies national sovereignty and international economic institutions to what extent must nations cede control over their economic and social policies if global efe ciency is to be achieved in an interdependent world this question is at the center of the debate over the future role of the wto formerly gatt in the realm of labor and environmental standards in this paper we establish that the market access focus of current wto rules is well equipped to handle the problems associated with choices over labor and environmental standards in principle with relatively modest changes that grant governments more sovereignty not less these rules can deliver globally efe cient outcomes i introduction to what extent must nations cede control over their economic and social policies if global efe ciency is to be achieved in an interdependent world at a broad level this question probes the limits of any international economic institution whether geared toward real or e nancial concerns that is designed to promote global efe ciency while respecting national sovereignty naturally the answer depends upon the particular problem that the institution is meant to solve in other words the answer depends upon the inefe ciency that would arise under unilateral policy choices at a more specie c level this question is at the center of the debate concerning the appropriate scope of the world trade organization wto formerly gatt recently member countries have considered ways to broaden the wto s orientation beyond conventional trade policy measures to include labor and environmental standards there are now initiatives to introduce the issue of labor standards directly onto the negotiating agenda of the wto with the purpose of creating a wto social clause the social clause would specify a set of minimum international labor standards and then permit restrictions to be placed against imports from countries not complying with these minimum standards with regard to environmental policies a wto committee on trade and environment has been established to identify the relationships between trade and environmental measures and to

inflation real returns and capital investment we find evidence for the hypothesis of mundell 1963 and tobin 1965 that the expected real return component of interest rates is negatively related to the expected inflation component in the mundell tobin model the variation in expected real returns is caused by the variation in expected inflation our evidence suggests however that the variation in expected real returns is more fundamentally an outcome of the capital expenditures process equilibrium expected real returns vary directly with capital expenditures in order to induce equilibrium allocations of resources between consumption and investment this positive relation between expected real returns and real activity which comes out of the real sector combines with a negative relation between expected inflation and real activity which is traced to the monetary sector thus inducing the negative relation between expected inflation and expected real returns predicted by mundell and tobin but explained in terms of a model much different from theirs

true or spurious long memory in volatility further evidence on the energy futures markets abstract the main goal of this paper is to investigate whether the long memory behavior observed in many volatility energy futures markets series is a spurious behavior or not for this purpose we employ a wide variety of advanced volatility models that allow for long memory and or structural changes the garch 1 1 the figarch 1 d 1 the adaptative garch 1 1 k and the adaptative figarch 1 d 1 k models to compare forecasting ability of these models we use out of sample forecasting performance using the crude oil heating oil gasoline and propane volatility futures energy time series with 1 month and 3 month maturities we found that five out of the eight time series are characterized by both long memory and structural breaks for these series dates of breaks coincide with some major economics and financial events for the three other time series we found strong evidence of long memory in volatility

forecasting volatility in the biofuel feedstock markets in the presence of structural breaks a comparison of alternative distribution functions abstract the need for research on commodity volatility has grown considerably due to the important role and financialization of commodities in global asset markets this paper examines the volatility forecasting performance of a wide variety of garch based models in the context of biofuel feedstock markets in the presence of structural breaks our sample is also extended to several non renewable energy commodities to evaluate comparatively the volatility forecasting performance across various commodity markets the model specifications allow for different conditional distribution functions in the rolling window estimations a break detection algorithm finds significant evidence of structural breaks in the unconditional variance of all commodity returns under study the out of sample analysis which is based on an up to date model comparison testing procedure reveals that volatility models accommodating structural breaks in the data provide the best volatility forecasts for most cases regarding the relevance of distribution functions the skewed normal distribution dominates in the model confidence sets nevertheless the complex distribution functions do not always outperform simpler ones although true return distribution is asymmetric and heavy tailed

the optimal tariff production lags and time consistency the optimal tariff for a large country equals the reciprocal of the foreign export elasticity of supply however if production decisions occur before consumption decisions the ex ante optimal tariff is not time consistent because the ex post elasticity is less than the ex ante elasticity we show all countries are worse off if the large country cannot precommit to its ex ante optimal tariff and that all countries can gain if the large country taxes domestic production of importables

money prices interest rates and the business cycle the mechanisms governing the relationship of money prices and interest rates to the business cycle are the most studied and most disputed topics in macroeconomics in this paper we first document key empirical aspects of this relationship we then ask how well three benchmark rational expectations macroeconomic models a real business cycle model a sticky price model and a liquidity effect model account for these central facts while the models have diverse successses and failures none can account for the fact that real and nom inal interest rates are inverted leading indicators of real economic activity that is none of the models captures the post war u s business cycle fact that a high real or nominal interest rate in the current quarter predicts a low level of real economic activity two to four quarters in the future i introduction the positive correlation of monetary aggregates and real economic activity over the course of many business cycles is a key empirical fact about the u s economy indeed the dynamic dimension of this covariation is so strong and stable that a monetary variable has long been included in the commerce department s index of leading economic indica tors while this pattern of cyclical comovement is widely agreed upon its interpretation is not some macroeconomists view money as purely passive with a positive response to varying levels of economic activity producing the positive correlation others view changes in the quantity of money as an important perhaps dominant source of economic fluctua tions frequently the real effects of monetary changes are suggested to arise from frictions in commodity labor or financial markets in economic theories that describe the influence of these frictions the transmission mechanism from monetary changes to real activity is typically viewed as involving interest rates and the price level the primary goal of this paper is to evaluate three models that explain the link between money prices interest rates and the business cycle we do this in three steps first we docu ment the cyclical behavior of these variables in the united states over the postwar period second we construct three quantitative rational expectations models of macroeconomic activity i a real business cycle model with endogenous money ii a model of commodity market frictions with mon etary non neutralities arising from gradual adjustment of goods prices and iii a model of financial market frictions with monetary non neutralities arising from gradual adjust ments of portfolios finally we compare the models predic tion for the business cycle behavior of money prices and interest rates with the data in exploring the predictions of these models we take the stock of money to be one of several exogenous variables in the system all of our models are capable of generating a forecasting role for money relative to real economic activity similar to that found in the u s data in the real business model monetary changes can forecast real activity because productivity is related to many underlying sources of shocks and because these real shocks also affect the money stock in the models with sticky prices and liquidity effects short hand names for the models with frictions in the com modity and financial markets monetary changes have an additional direct positive effect on aggregate output the outline of the paper is as follows section ii describes the data and documents its business cycle characteristics section iii outlines the three macroeconomic models and develops the particular quantitative versions of the models used in our analysis our main empirical results are pre sented in section iv and section v summarizes our results and concludes

why industrial policies fail limited commitment the strategic effects of subsidies on output and subsidies on investment differ substantially in dynamic models where a government s commitment ability is limited output subsidies remain effective even as the period of commitment vanishes but investment subsidies may become completely ineffective this difference has been obscured because most existing models of strategic trade policy are static copyright 1995 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

real exchange rates under the gold standard purchasing power parity is one of the most important equilibrium conditions in international macroeconomics empirically it is also one of the most hotly contested numerous recent studies for example have sought to determine the validity of purchasing power parity using data from the post bretton woods float and have reached different conclusions we assert that most such studies are flawed for two reasons first the post 1973 data contain by definition only a very limited amount of the low frequency information relevant for examination of long run parity second the dynamic econometric techniques used to model deviations from parity are typically quite crude with respect to admissible low frequency dynamics both deficiencies are rectified in the present paper with dramatic results we construct a new data set of 16 real exchange rates covering more than a century of the classic gold standard period and we study deviations from parity using long memory models that allow for subtle forms of mean

futures hedging with markov switching vector error correction fiegarch and fiaparch abstract markov switching vector error correction asymmetric long memory volatility models with fat tailed innovations are proposed bivariate two state versions of the models are applied to a futures hedge of the s p500 regime switches occur between high and low cost of carry states via changes in the error correction term or basis regime identification is therefore dominated by switches in the mean not volatility relative to a number of alternatives the proposed models provide superior out of sample forecasts of the covariance matrix particularly for horizons greater than 10 days ahead when hedging markov switching with long memory improves the tail risk of hedged returns beyond 10 day horizons however there is mixed support for models with volatility asymmetries these findings have important implications for the development of multivariate models and other applications including portfolio management spread option pricing and arbitrage

rules and discretion in trade policy abstract we argue that the second best nature of trade policy suggests that the issue of time consistency will be an important consideration in determining the extent and efficacy of such intervention if production decisions are made prior to consumption decisions governments with sufficient policy discretion will be tempted to surprise producers with policies other than those announced in an effort to separate the consumption tax aspect from the production subsidy dimension of a tariff this leads optimal trade policy to be time inconsistent in a wide range of environments we explore this idea and illustrate the results with specific examples

disadvantageous oil tariffs and dynamic consistency a large importer who places relatively greater weight on future than current oil consumption will import less oil in the future than if it were able to commit itself in advance to future tariffs and may find itself worse off than if it were unable to impose tariffs at all futures markets and storage modify these adverse effects and may avoid the problem of dynamic inconsistency copyright 1990 by american economic association

the new open economy macroeconomics a survey since the 1995 publication of obsteld and rogoff s redux model there has been an outpouring of research on open economy dynamic general equilibrium models that incorporate imperfect competition and nominal rigidities this paper offers an interim survey of this recent literature 2001 elsevier science b v all rights reserved

accounting for u s real exchange rate changes this study measures the proportion of u s real exchange rate movements that can be accounted for by movements in the relative prices of nontraded goods the decomposition is done at all possible h

time inconsistency of protectionist programs protectionist trade policies have long been advocated as second best instruments to achieve certain national objectives in situations where there is a market imperfection in essence protection provides time and resources for firms to undertake cost reducing investments recently there has been an emergence of new arguments to justify the implementation of a national industrial policy to encourage investment and to ensure the competitiveness of targeted industries also at the theoretical level a new argument known as strategic trade policy has emerged according to this argument protectionism gives domestic firms strategic advantage against foreign firms to capture a greater share of export markets where rents are not competed away actually the performance of protectionist programs has been grim industries have not adapted and protection has had to be renewed again and again arguments justifying protection have avoided this issue by implicitly assuming that authorities can credibly precommit to eliminate protection this is a very strong assumption in fact government actions are not exogenous but they are rather the result of an optimization process or they are best responses to political pressures as stressed in the public choice literature 2 therefore if authorities capitulate to protectionist pressures in the present they are unlikely to resist them in the future in the event that the targeted firm would not have adapted the inability of authorities to precommit to the unconditional elimination of protection generates a trade off for the firm if during the program the firm does not invest sufficiently in cost

persistence in variance structural change and the garch model this article examines the persistence of the variance as measured by the generalized autoregressive conditional heteroskedasticity garch model in stock return data in particular we investigate the extent to which persistence in variance may be overstated because of the existence of and failure to take account of deterministic structural shifts in the model both an analysis of daily stock return data and a monte carlo simulation experiment confirm the hypothesis that garch measures of persistence in variance are sensitive to this type of model misspecification

real and spurious long memory properties of stock market data we test for the presence of long memory in daily stock returns and their squares using a robust semiparametric procedure of lobato and robinson spurious results can be produced by nonstationarity and aggregation we address these problems by analyzing subperiods of returns and using individual stocks the test results show no evidence of long memory in the returns by contrast there is strong evidence in the squared returns

short term interest rates as predictors of inflation on testing the hypothesis that the real rate of interest is constant in an innovative and provocative paper in this review eugene fama presents evidence which appears to be consistent with the joint hypothesis that the real rate of interest ignoring taxes is a constant and that the market for u s treasury bills is efficient in the sense of embodying rational expectations those findings are strikingly at variance with a long list of previous studies which seemed to support the view that the real rate of interest varies over time and can be related to economic variables such as real output monetary policy and so forth 2 the methodologies which lead to these contradictory conclusions are quite different previous studies had followed the lead of irving fisher by relating nominal interest rates to distributed lags on past rates of inflation 3 these distributed lags are generally interpreted as approximations to the market s expected rate of inflation and thus any remaining variation is attributed to variation in the real rate 4 fama s methodology on the other hand draws on the fact that the difference between the market interest rate and the subsequently observed rate of inflation the ex post real interest rate consists by definition of the ex ante real interest rate plus a pure forecasting error 5 the hypothesis of market efficiency implies that these forecasting errors must be serially random thus observing ex post real rates is equivalent to observing ex ante real rates with random measurement error these errors of course confound the problem of identifying variation in the ex ante real rate in this paper we will argue that the relative magnitude of these measurement errors is such that the tests carried out by fama were not powerful enough to reject the joint hypothesis that the ex ante real rate is a constant and expectations are rational more powerful tests which are presented in this paper using the same data do lead to rejection of that hypothesis of course rejection