convergence to the law of one price without trade barriers or currency fluctuations using a panel of 51 prices from 48 cities in the united states we provide an upper bound estimate of the rate of convergence to purchasing power parity we find convergence rates substantially higher than typically found in cross country data we investigate some potentially serious biases induced by i i d measurement errors in the data and find our estimates to be robust to these potential biases we also present evidence that convergence occurs faster for larger price differences finally we find that rates of convergence are slower for cities farther apart however our estimates suggest that distance alone can only account for a small portion of the much slower convergence rates across national borders

spot and forward volatility in foreign exchange this paper investigates the empirical relation between spot and forward implied volatility in foreign exchange we formulate and test the forward volatility unbiasedness hypothesis which is the volatility analogue to the extensively researched hypothesis of unbiasedness in forward exchange rates using a new data set of spot implied volatility quoted on over the counter currency options we compute the forward implied volatility that corresponds to the forward contract on future spot implied volatility known as a forward volatility agreement we nd statistically signi cant evidence that forward implied volatility is a systematically biased predictor that overestimates future spot implied volatility the bias in forward volatility generates high economic value to an investor exploiting predictability in the returns to volatility speculation and indicates the presence of predictable volatility term premiums in foreign exchange

labour quality and aggregate real wage dynamics the real wage plays an important role in many aggregate econometrics studies of the labour market however average wages like any other average quantity can change for two reasons either through an underlying movement in the earnings potential of a unit of labour of given quality or alternatively through compositional changes which alter the relative proportions of different types of labour within the employed labour force using data from the general household survey to estimate earnings functions the paper seeks to examine the contribution of these two factors for britain from 1979 to 1989 it is shown that in periods of rising unemployment compositional changes can have a bigger effect on real earnings growth than any underlying change in reward to labour of give quality this raises the question of what economists actually are measuring when considering the behaviour of the aggregate real wage

price index convergence among united states cities we study the dynamics of price indices for major u s cities using panel econometric methods and find that relative price levels among cities mean revert at an exceptionally slow rate in a panel of 19 cities from 1918 to 1995 we estimate the half life of convergence to be approximately nine years the surprisingly slow rate of convergence can be explained by a combination of the presence of transportation costs differential speeds of adjustment to small and large shocks and the inclusion of nontraded goods prices in the overall price index do price indices in major u s cities share a common trend and if so how quickly do they revert to that trend following a local shock to the price index to answer this question we study the dynamics of consumer price indices for 19 major u s cities over the period from 1918 to 1995 the panel time series methods we employ are now commonly used for studying real output growth rates and levels of real exchange rates across countries we estimate that price index divergences across u s cities are temporary but surprisingly persistent with a half life of nearly nine years our research has two primary motivations first we hope to gain a better understanding of the sources of persistence in the deviations from purchasing power parity ppp found in studies of national price indices and exchange rate data second and more importantly we see the european monetary union as having many similarities to the united states and believe that studying the behavior of prices across u s cities will help us in understanding the likely nature of inflation convergence in the euro area the european central bank s stated inflation objective is a year on year change in the harmonized index of consumer prices hicp of not more than 2 but how large might we expect regional deviations from this euro area wide average to be and how long are they likely to persist the lack of data prevents us from answering this question directly using european prices under monetary union instead we look to the united states a mature common currency area of similar regional diversity size and industrial development

fiscal solvency and price level determination in a monetary union abstract this paper applies the fiscal theory of price level determination to the case of a monetary union a fiscal perspective suggests first that the focus of past studies on seigniorage per se may be misplaced second a rise in the level of debt by one member government can raise the common price level throughout the union suggesting a role for fiscal rules third conditions are discussed under which fiscal solvency is not necessary for each member government in a monetary union

relative implied volatility arbitrage with index options in the study reported here we investigated the efficiency of markets as to the relative pricing of similar risk by using implied volatilities of options on highly correlated indexes and a statistical arbitrage strategy to profit from potential mispricings we first analyzed the interrelationships over time of the three most highly correlated and liquid pairs of u s stock indexes based on this analysis we derived a relative relationship between implied volatilities for each pair if this relationship was violated i e if we detected a relative implied volatility deviation we suspected a relative mispricing we used a simple no arbitrage barrier to identify significant deviations and implemented a statistical arbitrage trade each time such a deviation was recorded we found that although many deviations can be observed only some of them are large enough to be exploited profitably in the presence of bid ask spreads and transaction costs

one market stocks futures and options during october 1987 we provide new evidence regarding the degree of integration among markets for stocks futures and options prior to and during the october 1987 market crash where previous analyses have resulted in recommendations for the implementation of circuit breakers the coordination of margin requirements across markets and changes in regulatory jurisdiction our analysis indicates that delinkage between markets during the crash was primarily caused by an antiquated mechanism for processing stock market orders the results suggest that market integration may be better served by efficient order execution than by further restricting markets

s p 100 index option volatility using transaction data on the s p 100 index options we study the effect of valuation simplifications that are commonplace in previous research on the timeseries properties of implied market volatility using an american style algorithm that accounts for the discrete nature of the dividends on the s p 100 index we find that spurious negative serial correlation in implied volatility changes is induced by nonsimultaneously observing the option price and the index level negative serial correlation is also induced by a bid ask price effect if a single option is used to estimate implied volatility in addition we find that these same effects induce spurious and unreasonable negative cross correlations between the changes in call and put implied volatility an important area of current research is the estimation and behavior of market volatility implied by option pricing models for example stein 1989 concludes that the s p 100 index option market is inefficient because longer term options overreact to changes in the implied volatility of short maturity options day and lewis 1988 document an increase in volatility around the quarterly expiration cycle schwert 1990 draws conclusions about the behavior of volatility around the stock market crash of 1987 by using implied volatility all of these studies use a simplified option pricing framework to estimate implied market volatility previous research generally assumes that the s p 100 index option is european style this option is actually american style it is also common to assume that the dividend yield is constant the dividends are not constant and exhibit distinct seasonal patterns harvey and whaley 1991b show that large pricing errors can be induced in the option prices if the american feature and the discrete dividends are ignored option pricing errors translate into errors in the implied volatility estimates this paper uses s p 100 index call and put transactions and an american style option pricing model with the exact discrete dividend series to calculate a time series of implied volatilities this valuation method

unemployment a survey this paper presents a survey of the economics of unemployment it covers competitive and imperfect competition models the role of different methods of wage determination and explanation of postwar unemployment patterns in the oecd countries copyright 1990 by royal economic society

the risk premium of volatility implicit in currency options this article provides an empirical investigation of the risk neutral variance process and the market price of variance risk implied in the foreign currency options market there are three principal contributions first the parameters of heston s mean reverting square root stochastic volatility model are estimated using dollar mark option prices from 1987 to 1992 second it is shown that these implied parameters can be combined with historical moments of the dollar mark exchange rate to deduce an estimate of the market price of variance risk these estimates are found to be nonzero time varying and of sufficient magnitude to imply that the compensation for variance risk is a significant component of the risk premia in the currency market finally the out of sample test suggests that the historical variance and the hull and white implied variance contain no more information than that imbedded in the heston implied variance

the costs of recession a reply pemberton i 995 raises the important issue of what is the most appropriate way to measure business cycle costs from an individual perspective as always in these matters it is not nor should it be a case of outright victory of one side over the other rather it is a question of which approach is the more plausible and on this we would wish to defend our shade of grey as being the more plausible measure this brief reply explains why imagine the simplest possible textbook experiment used to explain some of the principles of expected utility maximisation a prize in our case employed consumption c can be won with a given probability and the alternative is the booby prize of unemployed consumption let c be the expected value of this gamble and let c be the amount for which the player would be indifferent to the gamble the risk premium is then simply the difference between c and c this is exactly what is given by equation 9 in clark et al i994 equation 2 in pemberton s comment where the risk premium is measured as a proportion of employed consumption so there is nothing mysterious about our recession cost measure it is simply the standard textbook risk premium it would seem to us to be a very natural experiment to consider when measuring the cost of agents exposure to risks and we termed it the net cost measure our gross cost measure is given by i c c which is described by our equation 7 this is just the risk premium plus the difference between employed consumption and expected consumption again all measured relative to employed consumption we argued that the gross measure was one which would appeal to keynesians who because they view cycles as disequilibrium events would wish to include losses in consumption as part of the costs pemberton s statement that a high equilibrium natural rate of unemployment is surely a major problem is an implicit endorsement of the keynesian cost measure in our view the net measure because it measures the risk premium obviously abstracts away from any consumption losses as a result of drawing the booby prize this is exactly the same idea as lucas in his proposed cost measure who because of his view that business cycles are equilibrium events does not accept consumption losses as a proper part of costs the lucas measure and our own compare a risky consumption path with a riskless stream our measure differs from lucas however in one important respect from the macro perspective that he adopts the important comparison when measuring economic fluctuations and their impact on the welfare of representative agents is the deviation of consumption from its trend path thus lucas recession cost measure depends on the variance of consumption around that path unusually high aggregate consumption is as costly as unusually low

overreactions in the options market this paper examines the term structure of options implied volatilities using data on s p 100 index options because implied volatility is strongly mean reverting the implied volatility on a longer maturity option should move by less than one percent in response to a one percent move in the implied volatility of a shorter maturity option empirically this elasticity turns out to be larger than suggested by rational expectations theory long maturity options tend to overreact to changes in the implied volatility of short maturity options are investors rational do they behave like bayesian statisticians when it comes to incorporating new information into asset prices proponents of the efficient markets hypothesis would answer this question in the affirmative many others however believe that bayesian rationality is a poor description of investor behavior and that as a consequence asset prices tend to be informationally inefficient one way in which inefficiencies might arise is through the overreactions of traders to the arrival of new information 1 this possibility is raised by experimental and survey findings which indicate that people have a systematic tendency to overemphasize recent data at the expense of other information when making projections 2 the objective of this paper is to search for evidence of such overreactive behavior in a semingly peculiar place the options market options may appear to be unlikely candidates for overreaction because unlike primary securities their prices are closely tied down by arbitrage considerations as black and scholes 1973 demonstrate if stock price volatility is known options prices are completely determined any deviation from the prescribed value implies a riskless profit opportunity however given that volatility is in fact unknown and changing options do retain something of an independent nature not wholly redundant with their underlying stocks options can be thought of as reflecting a speculative market in volatility the implied volatility on a given option obtained by inverting a

fiscal and monetary rules for a currency union abstract this paper addresses the optimal joint conduct of fiscal and monetary policy in a two country model of a currency union with staggered price setting and distortionary taxes a tractable linear quadratic approximation permits a representation of the optimal policy plan in terms of targeting rules in the optimal equilibrium monetary policy should achieve aggregate price stability following a flexible inflation targeting rule fiscal policy should stabilize idiosyncratic shocks allowing for permanent variations of government debt but should abstain from creating inflationary expectations at the union level simple policy rules can approximate the optimal commitment benchmark through a mix of strict inflation targeting and flexible budget rules conversely the welfare costs of balanced budget rules are at least one order of magnitude higher than conventional estimates of the costs of business cycle fluctuactions

predicting volatility in the foreign exchange market measures of volatility implied in option prices are widely believed to be the best available volatility forecasts in this article we examine the information content and predictive power of implied standard deviations isds derived from chicago mercantile exchange options on foreign currency futures the article finds that statistical time series models even when given the advantage of ex post parameter estimates are outperformed by isds isds however also appear to be biased volatility forecasts using simulations to investigate the robustness of these results the article finds that measurement errors and statistical problems can substantially distort inferences even accounting for these however isds appear to be too variable relative to future volatility it is widely believed that the volatility implied in option prices is the market s best estimate of future volatility after all if it were not one could devise a trading strategy that could generate profits by identifying mispriced options the purpose of this article is to investigate the information content and predictive power of volatility implied in options on foreign currencies the paper focuses on options on currency futures traded on the chicago mercantile exchange cme because of the depth and liquidity of cme futures and options traded side by side in the same market implied standard deviations isds allow for clean tests of the predictive power of implied volatilities early studies of the information content of isds have generally found that these contain substantial information for future volatility latane and rendleman 1976 chiras and manaster 1978 and beckers 1981 for example regress future volatility on the weighted implied volatility across a broad sample of chicago board options exchange cboe stocks and find that options contain volatility forecasts that are more accurate than historical measures 1 these studies performed shortly after the 1973 beginning of the cboe option market could only use a relatively short time span and therefore focused on cross sections rather than time series predictions

stock market structure and volatility the procedure for opening stocks on the nyse appears to affect price volatility an analytical framework for assessing the magnitude of the structurally induced volatility is presented the ratio of variance of open to open returns to closeto close returns is shown to be consistently greater than one for nyse common stocks during the period 1982 through 1986 tbe greater volatility at the open is not attributable to the way in which public information is released since both the opento open return and the close to close return span the same period of time instead the greater volatility appears to be attributable to private information revealed in trading and to temporaryprice deviations induced by specialist and other traders the implied cost of immediacy at the open is significantly higher than at the close other empirical evidence in this article documents the volume of trading at the open the time delays between the exchange opening and the first transaction in a stock the difference in daytime volatility versus overnight volatility and the extent to which volatility is related to trading volume

the behavior of the volatility implicit in the prices of stock index options abstract we examine stock market volatility around the quarterly expirations of stock index futures contracts and nonquarterly expirations of stock index options using estimates of the volatility implicit in the option prices the option prices reflect increases in the volatility of the underlying stock indexes around both quarterly and nonquarterly expiration dates analysis of the residual returns on index options provides evidence consistent with an unexpected increase in market volatility around expiration dates

analysis of the term structure of implied volatilities from various empirical work it is well known that the volatility of asset returns changes over time this might be one of the reasons that implied volatilities differ for options that only differ in time to maturity we construct models for the relation between short and long term implied volatilities based on three different assumptions of stock return volatility behavior i e mean reverting garch and egarch models we test these relations on option price data and conclude that egarch gives the best description of asset prices and the term structure of options implied volatilities

the role of unemployment insurance in an economy with liquidity constraints and moral hazard the potential welfare benefits of unemployment insurance along with the optimal replacement ratio are studied using a quantitative dynamic general equilibrium model to provide a role for unemployment insurance agents in our economy face exogenous idiosyncratic employment shocks and are unable to borrow or insure themselves through private markets in the absence of moral hazard replacement ratios as high as 65 are optimal and the welfare benefits of unemployment insurance are quite large however if there is moral hazard and the replacement ratio is not set optimally but is instead set to an empirically plausible value the economy can be much worse off than it would be without unemployment insurance

insurance within the firm we evaluate the allocation of risk between firms and their workers using matched employer employee panel data unlike previous contributions this paper focuses on idiosyncratic shocks to the firm which are the correct empirical counterpart of the theoretical notion of diversifiable risk we allow for both temporary and permanent shocks to output and find that firms absorb temporary fluctuations fully but insure workers against permanent shocks only partially risk sharing considerations can account for about 15 percent of overall earnings variability the remainder originating from idiosyncratic shocks to individual workers our welfare calculations indicate that firms are an important vehicle of insurance provision

the fear and exuberance from implied volatility of s p 100 index options i study the relation between option traders risk perception and contemporaneous market conditions risk perception tends to increase when downside volatility increases more than upside volatility the risk return relation is asymmetric and nonlinear best described as a downward sloping reclined s curve that prior gains appear to have some mitigating effect on the fear of loss relative to prior losses points to a house money effect broader market conditions influence the perception of risk in a manner consistent with the keeping up with the joneses effect leverage is a weak explanation for the risk return relation

exchange rate systems and macroeconomic stability abstract we examine macroeconomic stability and the properties of the international transmission of business cycles under three exchange rate systems a flexible a unilateral peg ems and a single currency emu the subjects of study are germany and france in france macroeconomic volatility under emu is comparable to that under a flexible exchange rate system but considerably lower than that under ems in germany output volatility is significantly higher under ems relative to the flexible regime and increases even further under emu inflation though becomes more stable emu also induces a strong negative international transmission of country specific supply shocks and amplifies their role this fact may complicate ecb policymaking

the rationality of early exercise decisions evidence from the s p 100 index options market this study provides a comprehensive empirical analysis of the early exercise bistoty of sp but we show that a substantal number of these decisions are clearly irratonal since it would bave been possible to realize a larger riskless net cash jlow by seuling unlike p us studies of early exercise our tests of efflciency and the rationat decions tbatpresumably lead to eficient markets are model independet we also provide evidence concerning the relatve significance of dividends and the wild card to index optonpricing models and introduce and document the importance of the opton to exercise and avoid the indirect costs oftbe spread we alsofind evidence of a significant day of tbe week exercise effect and present some likely explanations for that effect

risk inflation and the stock market most explanations for the decline in share values over the past two decades have focused on the concurrent increase in inflation this paper considers an alternative explanation a substantial increase in the riskiness of capital investments we show that the variance of firms real gross marginal return on capital has increased significantly increasing the relative riskiness of investors returns on equity and that this can explain a large part of the market decline we also assess the effects of increase in the mean and variance of the inflation rate and a decline in firms expected return on capital this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item

errors in implied volatility estimation estimating implied volatility by inverting the black scholes formula is subject to considerable error when option characteristics are observed with plausible errors especially for options away from the money large changes in volatility produce small changes in option prices conversely small errors in option prices and other option characteristics produce large errors in implied volatilities in the presence of small measurement errors unobserved truncation of option prices that violate lower bounds for absence of arbitrage can also lead to systematic volatility smiles the paper proposes feasible gls estimators that reduce the noise and bias in implied volatility estimates

market risk and the concept of fundamental volatility measuring volatility across asset and derivative markets and testing for the impact of derivatives markets on financial markets this paper proposes an unobserved fundamental component of volatility as a measure of risk this concept of fundamental volatility may be more meaningful than the usual measures of volatility for market regulators fundamental volatility can be obtained using a stochastic volatility model which allows us to filter out the signal in the volatility information we decompose four ftse100 stock index related volatilities into transitory noise and unobserved fundamental volatility our analysis is applied to the question as to whether derivative markets destabilise asset markets we find that introducing european options reduces fundamental volatility while transitory noise in the underlying and futures markets does not show significant changes we conclude that for the ftse100 index introducing a new options market has stabilised both the underlying market and existing derivative markets

the terms of trade the real exchange rate and economic fluctuations this paper examines the relationship between terms of trade and business cycles using a three sector intertemporal equilibrium model and a large multicountry database results show that terms of trade shocks account for nearly one half of actual gdp variability the model explains weak correlations between net exports and terms of trade the harberger laursen and metzler effect and produces large and weakly correlated deviations from purchasing power parity and real interest rate parity terms of trade shocks cause real appreciations and positive interest differentials although productivity shocks have opposite effects the puzzle that welfare gains of international asset trading are negligible is left unresolved copyright 1995 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the persistence of volatility and stock market fluctuations this paper examines the potential influence of changing volatility in stock market prices on the level of stock market prices it demonstrates that volatility is only weakly serially correlated implying that shocks to volatility do not persist these shocks can therefore have only a small impact on stockmarket prices since changes in volatility affect expected required rates of return for relatively short intervals these findings lead us to be skeptical of recent claims that the stock market s poor performance during the 1970 s can be explained by volatility induced increases in risk premia this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item

cost of business cycles with indivisibilities and liquidity constraints it is almost universally agreed that individuals face incomplete insurance markets and cannot perfectly insure against the idiosyncratic risk in this paper simple general equilibrium models with incomplete insurance markets are examined in order to assess the impact of imperfect insurance on the magnitude of the welfare costs of business cycles two versions of incomplete insurance markets are considered and certain statistical properties of the equilibrium stochastic processes in these environments are compared with those of a perfect insurance economy

intraday price change and trading volume relations in the stock and stock option markets this study investigates intraday relations between price changes and trading volume of options and stocks for a sample of firms whose options traded on the cboe during the first quarter of 1986 after purging the price change series of the effects of bid ask spreads multivariate time series analysis is used to estimate the lead lag relation between the price changes in the option and stock markets the results indicate that price changes in the stock market lead the option market by as much as fifteen minutes the analysis of trading volume indicates that the stock market lead may be even longer the intense trading activity in and in fact the very existence of organized stock option markets attest to the economic benefits that these financial contracts provide reduced transaction costs and increased financial leverage are two reasons why trading in the stock option market may be more attractive than trading in the market for the underlying stock in addition these cheaper and more flexible trading opportunities attract new and differently informed investors to the marketplace the resulting increase in trading activity together with the inextricable arbitrage linkage between stock and option prices imply an increase in market efficiency this study investigates empirically the intraday price change and trading volume relations between stocks and options for a sample of firms whose options were actively traded on the chicago board options exchange during the first quarter of 1986 in particular intraday call option price changes are translated into implied stock price changes using the american call option pricing model these intraday implied stock price changes are then compared with the actual stock price changes to identify which if either market leads the other in perfectly functioning capital markets there should be complete simultaneity between the series that is new information disseminating into the marketplace should be reflected in the prices and the trading activity of both securities simultaneously institutional factors however may make the stock option market more attractive to information traders this may cause price changes and trading activity due to new information to be observed in the option market first followed by price

a note on a simple accurate formula to compute implied standard deviations abstract we derive a simple accurate formula to compute implied standard deviations for options priced in the classic framework developed by black and scholes 1973 and merton 1973 when a stock price is equal to a discounted strike price this formula reduces to a formula provided by brenner and subrahmanyam 1988 however their formula s accuracy is sensitive to stock price deviations from a discounted strike price the formula derived here extends the range of accuracy to a wide band of option moneyness

the costs of recession the paper measures the cost of business cycles by asking what proportion of consumption representative households whose head is currently employed would be prepared to give up to avoid the risk of unemployment previous estimates by lucas suggested that the costs of macroeconomic fluctuations measured in this way are surprisingly small the first part of the paper presents a critique of the lucas aggregate method showing that his estimates are not robust an alternative disaggregated framework is then developed and shows that the costs of macroeconomic fluctuations are significantly higher than those obtained by lucas consequently the view that inflation matters whereas business cycles are unimportant events is questioned copyright 1994 by royal economic society

endogenous growth and the welfare costs of inflation a reconsideration abstract many economists share the view that the welfare costs of moderate rates of money growth cum inflation are generally modest or small this paper investigates the sensitivity of this result to alternative model specifications and behavioral assumptions we first construct a monetary endogenous growth model with romer s 1986 style of capital externality and find that the real growth rate effect is substantially large thus lending to much higher welfare costs than those in existing studies to investigate the robustness of the result we then conduct a series of experiments by exploring the romer model with an alternative specification of money demand and a class of other endogenous growth models it is demonstrated quite consistently that our finding is confirmed in these models

fiscal policy and regional inflation in a currency union abstract substantial attention has been devoted to inflation differentials within the european monetary union including suggestions that inflation differentials are a policy issue for national governments this paper investigates the ability of a region participating in a currency union to affect its inflation differential with respect to the union through fiscal policy in a two region general equilibrium model with traded and nontraded goods lowering the labor income tax rate in response to positive inflation differentials succeeds in compressing inflation differentials such policies can lead to higher volatility of domestic inflation while leaving the volatility of real output roughly unchanged regional fiscal policies also have spill over effects on the volatility of union wide and foreign inflation in our model

market timing with option implied distributions a forward looking approach we address the empirical implementation of the static asset allocation problem by developing a forward looking approach that uses information from market option prices to this end we extract constant maturity s p 500 implied distributions and transform them to the corresponding risk adjusted ones then we form optimal portfolios consisting of a risky and a risk free asset and evaluate their out of sample performance we find that the use of risk adjusted implied distributions times the market and makes the investor better off than if she uses historical returns distributions to calculate her optimal strategy the results hold under a number of evaluation metrics and utility functions and carry through even when transaction costs are taken into account not surprisingly the reported market timing ability deteriorated during the recent subprime crisis an extension of the approach to a dynamic asset allocation setting is also presented this paper was accepted by wei xiong finance