further evidence on business cycle asymmetries in g7 countries this paper tests for business cycle symmetry in g7 countries during the post world war ii period using a number of tests each reflecting alternative definitions of business cycle asymmetry the tests are applied to monthly coincident economic indicators of business cycles this found that business cycles in the us are characterized by both longitudinal deepness and transversal steepness and sharpness asymmetries further it is found that asymmetric transition probabilties and time irreversibility are due to nonlinearities on the contrary business cycles in germany exhibits a symmetric behaviour between these extremes are the other countries for which at least one of the tests here considered rejects the null of cyclical symmetry particularly business cycle is characterized by deepness and sharpness in canada asymmetry in persistence in france and japan and asymmetric transition probabilities in france and united kingdom

u s and canadian industrial production indices as coupled oscillators abstract this paper uses ozaki s 1985 variable amplitude coefficient model to explore the impact of different types of dynamical linkages coupling between the indices of industrial production for the u s and canada empirical analysis reveals that for each country the requisite lag structure extends for up to six years and that the coupling linkages are functions of lagged changes in growth rates incorporating these linkages leads to an increased degree of oscillation in the equilibrium paths a marginal improvement in stability and somewhat greater synchronization between the two series the out of sample forecasts for each series are improved by the coupling

state lotteries and consumer behavior abstract this paper investigates two central issues regarding state lotteries first analyses of multiple sources of micro level data demonstrate that household lottery spending is financed primarily by a reduction in non gambling expenditures not by a reduction in expenditures on other forms of gambling the introduction of a state lottery is associated with an average decline of 46 per month or 2 4 percent in household non gambling expenditures low income households reduce non gambling household expenditures by 2 5 percent on average 3 1 percent when the state lottery includes instant games these households experience statistically significant declines in expenditures on food and on rent mortgage and other bills second consumer demand for lottery products responds positively to the expected value of the gamble controlling for other statistical moments and product characteristics including the nominal top prize amount this finding is consistent with informed choice among consumers of lottery products although other forms of irrational or misinformed choice cannot be ruled out

the brevity and violence of contractions and expansions abstract early studies of business cycles argued that contractions in economic activity were briefer shorter and more violent rapid than expansions this paper systematically investigates this claim and in the process discovers a robust new business cycle fact contractions in employment are briefer and more violent than expansions but we cannot reject the null of equal brevity and violence for expansions and contractions in output the difference arises because employment typically lags output around peaks but they coincide in their troughs we discuss the performance of existing business cycle models in accounting for this fact and conclude that none can fully account for it we then show that a business cycle model with asymmetric adjustment costs on employment and a choice of when to scrap old technologies can account for the business cycle fact both qualitatively and quantitatively

regional spending a comment on mackay mackay 2001 recently examined the regional pattern of taxation and spending in the uk concluding that for four regions london the south east scotland and northern ireland public expenditure was well above the level expected for their degree of prosperity mackay 2001 had a very approximate measure of the regional pattern of non identifiable government expenditure a major component of the latter is defence spending and a more precise allocation of this suggests that london and the south east get very preferential treatment moreover so does the south west which should be added to the list of well favoured regions this raises important issues of spatial balance and efficiency

policy debates government output and expenditure in uk regions and sub regions an analysis of the new experimental accounts data gripaios p and bishop p 2005 government output and expenditure in uk regions and sub regions an analysis of the new experimental accounts data regional studies 39 805 813 this paper examines the regional and sub regional distribution of uk state spending by analysing new data available from recently published regional government accounts the data indicate wide variations in public spending per head across regions with london being a particular beneficiary the results do not indicate any relationship between gross domestic product per head and public spending and they suggest that in total government spending is doing little to ameliorate regional inequality if the state wishes to pursue an active regional policy it hence needs to consider the regional dimension of all state functions not simply those associated with traditional regional policy

a lottery within a lottery an examination of the distribution of lottery funds in england the uk national lottery has been in operation since 1994 an examination of the regional distribution of awards per head of population suggests marked spatial disparities with london doing particularly well and scotland northern ireland wales and the north east faring much better than other regions such disparities also exist at english local authority level with london and some major provincial centres doing much better than more rural authorities such inequalities may give grounds for concern given that they appear to replicate those for other types of government spending the results of an empirical model designed to explain the spatial distribution of awards suggest that in addition to a london effect levels of deprivation have a positive impact another important explanatory variable which has a positive impact on lottery funding is the qualifications of residents which might plausibly reflect the quality of lottery bids received from an area however once these factors are taken account of

are business cycles asymmetric some european evidence economic thought has often regarded business cycles as asymmetric this study examines the existence of asymmetries over the business cycle in seven european countries france germany ireland italy luxembourg the netherlands and the united kingdom to analyse this issue industrial production in these countries from 1957 to 1998 is examined and quarterly contractions and expansions in this variable are compared the results obtained with both parametric and non parametric methods allow the existence of asymmetries in these countries to be questioned

time irreversibility and egarch effects in us stock index returns in this paper we suggest using a modified version of the time reversibility tr test of chen chou and kuan 2000 as a complementary diagnostic test for time series models the modified cck test is easy to compute and requires weaker moment conditions than existing tests our simulations demonstrate that this test is powerful against asymmetry in volatility but the bds test is not in the empirical study of us stock index returns we first find that these returns are all time irreversible applying the garch and egarch models to these returns we also find that the q and bds tests always accept the null hypothesis and cannot distinguish between these models by contrast the modified cck test accepts only the egarch model with an order that can accommodate the underlying asymmetry in volatility our results suggest that the detected time irreversibility in these return series may be attributed to volatility asymmetry and that such asymmetry may be captured using a proper egarch model copyright 2002 john wiley sons ltd

steepness and deepness in the australian macroeconomy this study uses nonparametric tests the triples test and the bds test to examine whether key australian macroeconomic aggregates exhibit nonlinearities and important steepness and deepness asymmetries at the business cycle frequency evidence is found of nonlinearities but there is little evidence of deepness in the australian macroeconomy however there is evidence of steepness especially concerning labour market variables as well as both the cpi and m3 the evidence suggests that unemployment employment rises falls rapidly in recessions and only recovers slowly over time also positive asymmetries in m3 are reflected in similar asymmetries in the cpi but not in output consumption or investment

regional taxing and spending the search for balance the financial settlement has been described as the key to devolution public spending above tax in scotland and wales has been criticized public spending is above tax in seven uk regions including four english regions if we treat equal citizens equally public spending will be above tax in poorer regions there is nothing extraordinary about spending above tax but there are important questions with regard to regional levels of expenditure in four regions london south east scotland and northern ireland public expenditure is well above the level expected for their degree of prosperity this article provides possible explanations

a periodic review production planning model with uncertain capacity and uncertain demand optimality of extended myopic policies increasing product complexity manufacturing environment complexity and an increased emphasis on product quality are all factors leading to uncertainties in production processes these uncertainties are in the form of unplanned machine maintenance varying production yields and rework among others in planning for production an adequate model must incorporate these uncertainties into the representation of the production process this paper treats the aggregate planning problem for a single product with random demand and random capacity in the single period problem random capacity does not affect the optimal policy but results in a unimodal nonconvex cost function in the multiple period and infinite horizon settings order up to policies that are dependent on the distribution of capacity are shown to be optimal in spite of a nonconvex cost in the infinite horizon setting an intuitive description of the situation leads to the notion of a class of extended myopic policies requiring the consideration o

the structure of periodic review policies in the presence of random yield this work provides a comprehensive analysis of a general periodic review production inventory model with random variable yield existence of an order point whose value does not depend on yield being random is proved in the single period case without specifying the yield model and using a very general cost structure when yield is a random multiple of lot size the nonorder up to optimal policy is characterized for a finite horizon model the finite horizon value functions are shown to converge to the solution of an infinite horizon functional equation and the infinite horizon order point is shown to be no smaller than when yield is certain

slow boom sudden crash abstract many asset markets exhibit slow booms and sudden crashes this pattern is explained by an endogenous flow of information in the model agents undertake more economic activity in good times than in bad economic activity generates public information about the state of the economy if the economic state changes when times are good and information is abundant asset prices adjust quickly and a sudden crash occurs when times are bad scarce information and high uncertainty slow agents reactions as the economy improves a gradual boom ensues data from u s and emerging credit markets support the theory

cointegration and threshold adjustment this article proposes an extension to the engle granger testing strategy by permitting asymmetry in the adjustment toward equilibrium in two different ways we demonstrate that our test has good power and size properties over the engle granger test when there are asymmetric departures from equilibrium we consider an application namely whether there exists cointegration among interest rates for instruments with different maturities this issue has been widely tested with mixed results we argue that either cautious policy or possibly opportunistic behavior on the part of the federal reserve implies that an equilibrium relationship between short and long term interest rates exists but that adjustments from disequilibrium are asymmetric in nature empirical tests using u s yields confirm the asymmetric nature of error correction among interest rates of different maturities

multi country tests for the oscillator model with slowly varying coefficients abstract this paper applies ramsey s 1992 forced oscillator model discovered with us data to canada japan uk belgium france germany and italy we also examine the aggregate production index for consumer goods in the us thus the model is applied to and the results checked against data that were not involved in the discovery of the model in the original paper the adequacy of the model is evaluated and international comparisons are made the similarity of the estimates for all of the data sets examined suggest that the model may be widely applicable for consumer goods production indices although france and italy provide partial exceptions to this statement

long run purchasing power parity with asymmetric adjustment further evidence from african countries this study applies threshold cointegration test advanced by enders and siklos 2001 to investigate the properties of asymmetric adjustment in long run purchasing power parity ppp in 22 selected african countries during the period of january 1980 to december 2003 although there is evidence of long run ppp for most african countries the adjustment mechanism is asymmetric these results have particularly important policy implications for african countries

probability of purchase amount of purchase and the demographic incidence of the lottery tax abstract when consumers indifference curves are discontinuous at zero perhaps due to stigma or fixed costs of purchase then factors influencing the amount purchased will have a different effect on the probability of purchase estimation of the demand for a commodity like lottery tickets requires a procedure that accounts for this tobit estimation commonly used in this literature does not allow for this generalization we investigate individual lottery ticket purchases using data from a survey of households our results are quite disparate from earlier studies regarding the effects of many demographic variables on probability of play level of play and expected lottery ticket purchases and imply a different demographic incidence of the lottery tax than previous studies suggest

the regional dimension of public expenditure in england public expenditure in the uk has a location dimension with respect to the devolved arrangements for scotland wales and northern ireland there is no location dimension to the allocation of public expenditure to the regions of england nevertheless whether planned or not public expenditure impacts on the regions through the provision of services and associated employment and income generation this paper examines the methodological issues in assigning public expenditure to countries and regions and reviews existing and past patterns of public expenditure in english regions it then considers the relevance of this analysis to policy options for introducing an explicit regional dimension to the public expenditure allocation mechanism in england paradoxically english regional devolution is potentially more radical in its implications in terms of rupturing existing allocative mechanisms that lead to flows of expenditure than devolution in the territories where it can be interpreted as putting democrat

world business cycles under fixed and flexible exchange rates this paper studies the behavior of monthly industrial production indices during the recent periods of fixed and flexible exchange rate s the central conclusions are as follows industrial production indices are subject to stochastic trend growth the variances of the monthly growth rates are higher in the flexible exchange rate period than in the fixed exchange rate period and are related to the degree of openness and to national income more open economies tend to experience more variability while richer more diversified economies experience less and output movements have been correlated across countries under both exchange rate regimes and there is evidence of a world business cycle copyright 1988 by ohio state university press

replenish up to inventory control policy with random replenishment intervals abstract the multi period inventory problems have been studied under two main assumptions continuous review assumption where an order can be made at any time depending on inventory position and periodic review assumption where an order can be initiated only at discrete time epochs in this study we analyze a multi period inventory problem that falls under neither of these two assumptions in the case we consider there are periodic replenishments but the replenishment intervals are taken to be i i d random variables this setting represents the real life cases where a supplier visits a retailer with random inter arrival times and the retailer replenishes his inventories based on a replenish up to level inventory control policy we also assume that only a certain fraction of unmet demand is backordered and the rest of it is lost in this setting under general distribution between replenishment epochs we show the concavity of the expected profit function and give the condition that must hold for the optimal replenish up to level we also present the specific solutions and analysis under two different distributions namely uniform and exponential distributions together with some numerical examples

inventory control in a fluctuating demand environment we present an inventory model where the demand rate varies with an underlying state of the world variable this variable can represent economic fluctuations or stages in the product life cycle for example we derive some basic characteristics of optimal policies and develop algorithms for computing them in addition we show that certain monotonicity patterns in the problem data are reflected in the optimal policies

the welfare effects of lotto evidence from the uk abstract this paper estimates the demand for lottery tickets using pooled cross section data that contain individual incomes and extensive information about characteristics one of the cross sections corresponded to a draw which was a double rollover the jackpot was enhanced by adding the two previous draws jackpots which had not been won together these datasets provide sufficient observations facing different prices to allow us to estimate the price elasticity as well as the income elasticity of demand we estimate tobit and other specifications and use the estimates to evaluate the welfare effects arising from the introduction of the lottery

analysis of an inventory system under supply uncertainty in this paper we analyze a periodic review single item inventory model under supply uncertainty the objective is to minimize expected holding and backorder costs over a finite planning horizon under the supply constraints the uncertainty in supply is modeled using a three point probability mass function the supply is either completely available partially available or the supply is unavailable machine breakdowns shortages in the capacity of the supplier strikes etc are possible causes of uncertainty in supply we demonstrate various properties of the expected cost function and show the optimality of order up to type policies using a stochastic dynamic programming formulation under the assumption of a bernoulli type supply process in which the supply is either completely available or unavailable and when the demand is deterministic and dynamic we provide a newsboy like formula which explicitly characterizes the optimal order up to levels an algorithm is given that computes the optimal inventory levels over the planning horizon extensions and computational analysis are presented for the case where the partial supply availability has positive probability of occurrence

government expenditures and revenues evidence from asymmetric modeling 1 introductionexamining the empirical relationship between government revenues and expenditures is a crucial step in understanding the future path of the budget deficit four alternative explanations have been used to describe the relationship between these variables in the budgetary process i the tax and spend hypothesis ii the spend and tax hypothesis iii the fiscal synchronization hypothesis and iv the institutional separation hypothesis the issue of which hypothesis best describes the nature of the budgetary process has yet to be resolved in the literature however existing research has implicitly assumed that the state of the budget and whether or not the budget deficit or surplus is worsening or improving does not matter we argue that government decision makers may take these factors into account when determining expenditures and tax policy as such this article reexamines the tax spend debate by using a more robust econometric technique that allows for asymmetry in the relationship between revenues and expenditures until now the empirical evidence on the tax spend debate has focused almost exclusively on two conventional econometric techniques depending on the cointegrating properties between revenues and expenditures these techniques are based on either variations of the unrestricted vector autoregression uvar or the vector autoregression error correction model ecm 1 if for example the two budgetary variables are not cointegrated then the application of causality2 tests requires the use of stationary variables in the uvar model 3 on the other hand if the two budgetary variables are cointegrated then the application of causality tests requires an ecm specification it is important to note that the ecm specification implicitly assumes that the adjustment process of expenditures and revenues due to disequilibrium between the variables is strictly symmetric indeed if the adjustment is asymmetric then the symmetric adjustment implicitly assumed in the conventional techniques to ascertain causality implies model misspecification this specification error may lead to misguided and perhaps inappropriate fiscal policy decisions accurate estimation of the revenue and expenditure process is especially important as changes in taxes and spending alter incentives for work investment and productive activity cea 2004 thus the anticipated behavioral responses of households and businesses may be better captured by more general models that allow for asymmetry in the tax spend relationship to this end this article examines the existence of cointegration between revenues and expenditures and the corresponding ecm specification by using the recently developed techniques of asymmetric modeling in particular we employ the threshold autoregression tar and momentum threshold autoregression m tar models developed by enders and granger 1998 and enders and siklos 2001 within the context of these models we shed new light on whether budget surpluses versus budget deficits or an improving budget versus a worsening budget have asymmetric effects on the dynamic behavior of expenditures and revenues there is an a priori rationale for modeling asymmetry in the budget and for the response of its components to disequilibrium this rationale can be categorized into four factors first the fiscal policymakers may respond differently to a deviation of the deficit or surplus from its long run trend one would expect for example that the response would be more aggressive if the deficit was greater than its long run trend than if it was less than its trend second it is widely acknowledged that there is a very close connection between the budget and the business cycle through automatic fiscal stabilizers and discretionary fiscal measures to the extent that the business cycle is asymmetric the associated change in the budget may also be asymmetric

the equilibrium relationship among money income prices and interest rates evidence from a threshold cointegration test the long run equilibrium relationship among money income prices and interest rates in japan is investigated by the threshold cointegration test which allows for asymmetric adjustment introduced by enders and siklos 2001 the threshold cointegration approach provides clear evidence of the cointegration relationship characterized by asymmetric adjustment by allowing for asymmetric adjustment results are obtained showing the stability of the money demand function similar to lucas 1988 who pointed out that the money demand function is stable if unit income elasticity is imposed in particular the estimated results show that the adjustment process toward equilibrium is highly persistent above an appropriately estimated threshold whereas the adjustment process toward equilibrium quickly converges below it this finding indicates that deviations from equilibrium resulting from increases in money or decreases in income and prices are highly persistent

do recessions permanently change output abstract this paper examines whether negative innovations to gnp are more or less persistent than positive innovations we find that once we allow for the impulse response of gnp to be asymmetric negative innovations to gnp are observed to be much less persistent than positive ones in particular the effect of a recession on the forecast of output is found to be negligible after only eight to twelve quarters while the effect of a positive shock is estimated to be persistent and amplified over time our results may therefore help reconcile two antagonistic views about the nature of business cycle fluctuations

time irreversibility and business cycle asymmetry the problem of business cycle symmetry is addressed within the context of time reversibility to this effect the authors introduce a time domain test of time reversibility the tr test in an application they show that time irreversibility is the rule rather than the exception for two well known representative macroeconomic data sets this shows that many components of the business cycle have asymmetric fluctuations the characterization of asymmetry provided by the tr test shows that many series exhibit steepness asymmetry a few series appear to be either deep or sharp copyright 1996 by ohio state university press

asymmetry in business fluctuations international evidence on friedman s plucking model abstract friedman s plucking model of business fluctuations suggests that output cannot exceed a ceiling level and it is occasionally plucked downward by recession output has depth and steepness this study uses a sample of 12 industrial and emerging economies and finds some evidence that negative shocks are largely transitory while positive shocks are mostly permanent in a few cases as implied by the plucking model output fluctuations tend to be asymmetric recessions are transitory and duration dependent although expansions are not there is however serial correlation in almost all cases international evidence on friedman s plucking model is far from robust

are statistical reporting agencies getting it right data rationality and business cycle asymmetry this article provides new evidence on the rationality of early releases of industrial production ip and producer price index ppi data rather than following the usual practice of examining only first available and fully revised data we examine the entire revision history for each variable thus we are able to assess for example whether earlier releases of data are in any sense less rational than later releases and when data become rational our findings suggest that seasonally unadjusted ip and ppi become rational after approximately 3 4 months whereas seasonally adjusted versions of these series remain irrational for at least 6 12 months after initial release for all variables examined we find evidence that the remaining revision is predictable from its own past or from publicly available information in other economic and financial variables in addition we find a clear increase in the volatility of revisions during recessions suggesting that early data releases are less reliable in toughe

inventory models with random yield in a random environment abstract we consider a single item inventory model which is observed periodically in a randomly changing environment all model parameters are specified by the state of the environment which is assumed to be a time homogeneous markov chain yield is random due to the random capacity of the vendor i e a given order is fully received if the order quantity is less than this capacity otherwise the quantity received is equal to the available capacity the problem is analyzed in single multiple and infinite periods and it is shown that in all cases the optimal policy is the well known base stock policy where the optimal order up to level depends on the state of the environment the results are compared with the solutions of the certain yield model when there is infinite capacity we show that the order up to levels are equal in the single period case however in multiple and infinite periods we order the same or more if the yield is random

non linearities in the dynamics of oil prices abstract examining stationarity is of particular importance and represents the first step in empirical time series research non stationarity invalidates many of the results obtained from standard techniques and therefore requires special treatment because oil prices play an important role in affecting economic variables this paper examines the stationarity of real oil prices brent dubai wti and the world over the period 1973 2 2011 2 real oil prices are expressed in the currencies of seven asian countries indonesia japan korea malaysia the philippines singapore and thailand and in the u s dollar while using linear unit root tests without structural breaks shows no evidence of stationarity allowing for breaks shows very limited evidence of stationarity we argue that these results are attributed to the presence of nonlinearities in the behavior of oil prices testing for nonlinearity shows significant evidence of nonlinearity in all the cases with evidence of exponential smooth transition autoregression estar nonlinearity type in most cases applying unit root tests that account for two types of nonlinearities smooth transition and nonlinear deterministic trends reveals evidence of stationarity in all the cases

an empirical characterization of the dynamic effects of police spending on violent and property crime the study estimates the dynamic effects of shocks to police expenditures on measures of violent and property crime rates using annual u s state level data for the period 1960 2015 we employ a structural panel var model and achieve identification by imposing the restriction that police spending responds to structural shocks to crime with at least a lag of 1 year results indicate that a shock to police spending leads to a persistent and significant decreases in violent and property crime rates and b significant and persistent negative impacts on crime rates in periods of high crime but little impacts in periods of low crime variance decompositions show that shocks to police spending account for moderate to large proportions of the variability of u s state level crime rates our findings are robust across separate measures of violent and property crime rates as well as to the inclusion of additional variables to the baseline panel var model jel k42

the economic analysis of lotteries lotteries determinants of ticket sales and the optimal payout rate this paper considers policy issues arising in the design regulation and taxation of lotteries focusing on the market for an on line lottery game demand determines who buys lottery tickets and in what quantities the design of lotteries affects the terms on which tickets are supplied uk data suggest that its lottery may be priced too high to maximize lottery revenue more revenue might be raised if the proportion of sales allocated to tax and other levies were smaller having established the positive economics of lotteries the paper then assesses their welfare implications pari mutuel lotteries enjoy scale economies and as natural monopolies are invariably run either by government agencies or a regulated licensee i estimate consumer surplus and identify the excess burden that arises from existing over taxation of lotteries the large price elasticity of demand implies that revenue raised from the lottery is raised very inefficiently moreover the demand for lottery tickets is inferior and there is some evidence that such games are contagious and addictive so using lotteries as a vehicle for raising revenue is extremely regressive finally i consider other policy implications induced effects on charitable giving and on other forms of gambling the impact on the government budget perceptions of risk and distributional considerations ian walker

inventory control with information about supply conditions this paper presents an inventory control model which includes a markovian model of the supply system as that system evolves over time so do the replenishment leadtimes the optimal policy has the same structure as in standard models but its parameters change dynamically to reflect current supply conditions in this setting contrary to conventional wisdom a longer leadtime does not necessarily imply more inventory the leadtime is important but so is a concept we call order coverage

optimal policies for inventory systems with finite capacity and partially observed markov modulated demand and supply processes we analyze a single item periodic review inventory system with random yield and finite capacity operating in a random environment the primary objective is to extend the model of gallego and hu 2004 to the more general case when the environment is only partially observable although our analysis is specific to inventory systems it can also be applied to production systems by replacing the fixed capacity supplier with a fixed capacity producer using sufficient statistics we consider single period multiple period and infinite period problems to show that a state dependent modified inflated base stock policy is optimal moreover we show that the multiple period cost converges to the infinite period cost as the length of the planning horizon increases

is investment time irreversible some empirical evidence for disaggregated uk manufacturing data it has long been suggested that investment may be time irreversible and consideration of the option value of waiting to invest has aroused renewed interest in this issue this study tests for time irreversibility in uk investment according to disaggregation by type of investment expenditure and across manufacturing sector groupings the test results reported indicate that the irreversibility of investment patterns varies not only from industry to industry but also according to the type of capital being purchased with significant time irreversibility detected in gross fixed capital formation and aggregate vehicles expenditure and industrial sector groupings comprising fuels and oil refining engineering and vehicles and textiles and leather however only in the first and last of these series is time irreversibility attributable to non linearities in the underlying data generating process and consistent with threshold effects which may be associated with s s type models of investment dynamics

periodic review production models with variable capacity random yield and uncertain demand we investigate a production planning problem in a periodic review environment with variable production capacity random yields and uncertain demand the implications of random yields and variable capacity for lot sizing previously have been explored separately but not jointly many production environments are likely to be subject to both types of uncertainties to minimize the total discounted expected costs production holding and shortage costs we formulate the problem as a stochastic dynamic program for the finite horizon problem we prove that the objective function is quasi convex and that the structure of the optimal policy is characterized by a single critical point for the initial stock level at each period that is if the initial stock is greater than this critical point the optimal planned production is zero otherwise it is greater than zero expressions for solving the critical point and the optimal planned production are obtained we further show that the solution for the finite horizon problem converges to that of the infinite horizon problem

robust measures of skewness and kurtosis for macroeconomic and financial time series abstractthe sample skewness and kurtosis of macroeconomic and financial time series are routinely scrutinized in the early stages of model building and are often the central topic of studies in eco

are health expenditures and gdp characterized by asymmetric behaviour evidence from 11 oecd countries in this article we examine whether per capita health expenditures and per capita gdp for 11 oecd countries can be characterized by asymmetric behaviour we achieve this goal by using the nonparametric triples test suggested by randles et al 1980 we examine two forms of asymmetries namely deepness and steepness our main finding is that for 6 out of 11 countries namely for the usa the uk japan spain finland and iceland either per capita health expenditures or per capita gdp are characterized by asymmetric behaviour this finding to some extent casts doubt on those studies that model the relationship between health and gdp using unit root and cointegration tests that assume symmetric disturbances

time reversibility tests of volume volatility dynamics for stock returns abstract non parametric tests based on the concept of time reversibility in statistical mechanics are applied to assess the dynamic implications of the mixture of distributions hypothesis mdh the tests show that shocks to volume and volatility are dynamically asymmetric thus rejecting the one factor mdh

adaptive inventory control for nonstationary demand and partial information this paper examines several different policies for an inventory control problem in which the demand process is nonstationary and partially observed the probability distribution for the demand in each period is determined by the state of a markov chain the core process however the state of this core process is not directly observed only the actual demand is observed by the decision maker given this demand process the inventory control problem is a composite state partially observed markov decision process pomdp which is an appropriate model for a number of dynamic demand problems in practice managers often use certainty equivalent control cec policies to solve such a problem however this paper presents results that demonstrate that there are other practical control policies that almost always provide much better solutions for this problem than the cec policies commonly used in practice the computational results also indicate how specific problem characteristics influence the performance of each of the alternative policies

inventory management with random supply and imperfect information a hidden markov model in most of the papers on inventory models operating in a random environment the state of the environment in each period is assumed to be fully observed with perfect information however this assumption is not realistic in most real life situations and we provide a remedy in this paper by assuming that the environment is only partially observed with imperfect information we accomplish this by analyzing two formulations of single item models with periodic review and random supply in a random environment in the first one supply is random due to random capacity of production and random availability of transportation we show that state dependent base stock policy is optimal if the capacity and all costs are observed while demand and availability are unobserved in the second model we consider a model with random availability only with fixed ordering cost we show that state dependent s s policy is optimal if the availability process is observable