the effect of supply uncertainty in price setting newsvendor models abstract we consider a price setting newsvendor model in which a firm needs to make joint inventory and pricing decisions before the selling season the supply process is uncertain such that the received quantity is the product of the order quantity and a random yield rate two cost structures are investigated the in house production case in which the firm pays for the input quantity and the procurement case in which the firm pays for the quantity received only our objective is to investigate the effect of yield randomness on optimal decisions and expected profit by using the theory of stochastic comparisons we find that under both cost structures a less variable yield rate leads to a lower optimal price and a higher expected profit moreover we show that in the in house production case a stochastically larger yield rate also results in a lower optimal price and a higher profit but this is not true in the procurement case examples show that the effect of supply uncertainty on optimal order quantity is not universal

optimal supply diversification under general supply risks we analyze a planning model for a firm or public organization that needs to cover uncertain demand for a given item by procuring supplies from multiple sources the necessity to employ multiple suppliers arises from the fact that when an order is placed with any of the suppliers only a random fraction of the order size is usable the model considers a single demand season with a given demand distribution where all supplies need to be ordered simultaneously before the start of the season the suppliers differ from one another in terms of their yield distributions their procurement costs and capacity levels the planning model determines which of the potential suppliers are to be retained and what size order is to be placed with each we consider two versions of the planning model in the first the service constraint model scm the orders must be such that the available supply of usable units covers the random demand during the season with at least a given probability in the second version of the model the total cost model tcm the orders are determined so as to minimize the aggregate of procurement costs and end of the season inventory and shortage costs in the classical inventory model with a single fully reliable supplier these two models are known to be equivalent but the equivalency breaks down under multiple suppliers with unreliable yields for both the service constraint and total cost models we develop a highly efficient procedure that generates the optimal set of suppliers as well as the optimal orders to be assigned to each most importantly these procedures generate a variety of important qualitative insights for example regarding which sets of suppliers allow for a feasible solution both when they have ample supply and when they are capacitated and how various model parameters influence the selected set of suppliers the aggregate order size and the optimal cost values

limited commitment and the demand for money understanding money demand is important for our comprehension of macroeconomics and monetary policy its instability has made this a challenge common explications for the instability are financial regulations and financial innovations that shift the money demand function we provide a complementary view by showing that a model where borrowers have limited commitment can significantly improve the fit between the theoretical money demand function and the data limited commitment can also explain why the ratio of credit to m1 is currently so low despite that nominal interest rates are at their lowest recorded levels this article is protected by copyright all rights reserved

demand for money in open economies abstract the demand for real cash balances deduced from an underlying portfolio model of the financial market is shown to depend upon domestic variables and foreign monetary developments the model is estimated using quarterly postwar data for canada germany uk and us there is clear evidence that demand for money is affected not only by changes in domestic variables such as permanent income domestic interest rate and price expectations but also by fluctuations in exchange rate expectations and foreign interest rates the conclusion that domestic monetary policy is fairly ineffective and domestic financial markets are highly vulnerable to changes in foreign financial and monetary developments need to be modified in light of the results presented in this paper

re examining the buffer stock model of money this paper critically examines recent papers in the buffer stock or supply side disequilibrium models of money the paper first investigates the assumptions at the m icroeconomic level and concludes that even with these assumptions aggregate behavior does not necessarily follow buffer stock models in which excess cash balances are held involuntarily in a simple model with uncertain cash flows it is shown that in the aggregate short run involuntary cash holdings are negligible if the buffer stock story is applicable it is to a broader definition of money than used in most empirical work the second part of the paper examines empirical work and argues that the buffer stock idea cannot be implemented using single equation techniques and that when viewed appropriately current empirical result s refute the buffer stock idea as it is currently modeled copyright 1987 by royal economic society

the demand for money in developing countries assessing the role of financial innovation traditional specifications of money demand have commonly been plagued by persistent overprediction implausible parameter estimates and highly autocorrelated errors the authors argue that some of these problems stem from the failure to account for the impact of financial innovation they estimate money demand for ten developing countries using various proxies for financial innovations they also assess the relative importance of this variable finding financial innovation can be better modeled as a stochastic random walk trend rather than a deterministic time trend financial innovation plays an important role in determining fluctuations of the demand for money the importance of this role increases with the rate of inflation

effects of financial innovations on the money demand function a canadian evidence a money demand function for the candian economy has been estimated to explore if recent financial innovations have caused any significant change in the structural relationship between the demand for money and its determinants two sets of estimation results have been analysed the first set is obtained by estimating a standard money demand function for several overlapping sample periods and the other set is obtained by estimating a modified version which included a dummy or a ratchet variable to capture the effects of innovations the estimated equations have been used to generate ex post simulations and forecasts the results suggest that innovations have displaced the money demand function in the early 1980s it also appears that the incorporation of approriate innovation variables improves the predictive performance of the money demand function

modelling money demand in open economies over the modern floating rate period the role of open economy factors in influencing domestic money demand in major industrial countries over the modern floating rate period is examined the theoretial model for the empirical analysis is derived from a general two country portfolio balance framework that determines the demand for domestic and foreign monetary and non monetary assets in each country the ecm estimates indicate that capital mobility plays an important role in the money demand function in all seven counteries considered currency substitution in contrast is not an important phenomenon

an improved model for supplier selection under capacity constraint and multiple criteria abstract ghodsypour and o brien 2001 the total cost of logistics in supplier selection under conditions of multiple sourcing multiple criteria and capacity constraint international journal of production economics 73 1 15 27 study multiple sourcing problem with multiple criteria and capacitated suppliers considering the buyer s quality requirements as a constraint they develop a mixed integer non linear programming model to find the least cost cyclic ordering policy for the buyer they propose to solve the model by enumerating over all possible supplier combinations although the problem is interesting and their analysis is correct we point out two issues with their assumptions namely capacitated suppliers and cyclic ordering policy we discuss two different capacitated supplier settings i long run average annual capacity and ii exact annual capacity first under long run average annual capacity assumption we propose a model which provides the same or a better solution and is much easier to solve than their model then we discuss how to modify our and their models to handle exact annual capacity assumption

does the federal reserve respond to errant money growth evidence from three monetary regimes this paper tests the hypothesis that the federal reserve responds to deviations between actual and targeted money growth with a corrective adjustment in their policy instrument the authors divide the sample period of 1975 87 into three monetary regimes their results suggest that the fed responded to errant money growth in the pre 1979 and the 1979 82 subperiods however the authors find no evidence that the fed responded to errant money growth in the post 1982 subperiod these results yield some insights into the source of the money supply announcement puzzle by lending support for what has been termed the policy anticipation effect copyright 1992 by ohio state university press

estimating money demand functions the question of which functional forms of money demand regression equations are useful for empirical work is addressed here specifically it is argued that a functional form that focuses attention on the ability of the growth rate of nominal money to predict the inflation rate is a useful way of summarizing empirical evidence on the existence of a stable money demand function the results of estimating and simulating this functional form as well as standard functional forms are presented in the final part of this paper a typical equation expressing the public s demand for real money balances m is as follows

the identification of monetary policy disturbances explaining the liquidity puzzle abstract this paper examines recent work on the identification of monetary policy disturbances its main finding is that the empirical anomalies found in the literature reflect a failure to properly address the federal reserve s policy of accommodating reserve demand shocks a new method of identifying monetary policy using nonborrowed reserves is proposed using this specification policy has a strong persistent liquidity effect regardless of subsample policy granger causes output even in the presence of interest rates explaining approximately 49 of the variance in output at a two year horizon and the residual explanatory power of interest rates for output is negligible

nominal costs and the demand for real transactions balances the standard specification of constant real transactions costs assumes that over the sample period transactions costs move in lock step with the gnp deflator our model assumes that transactions costs move negligibly compared to the gnp deflator that is nominal transactions costs are assumed constant here rather than real transactions costs as in other estimates of money demand we find with this nominal transactions cost specification that the real money demand function is more stable in terms of the stability of the coefficients and the accuracy of out of sample predictions than indicated by earlier studies

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

analysis of compound bullwhip effect causes abstract this research investigates compound causes of the bullwhip effect bwe by considering an inventory system with multiple price sensitive demand streams joint price and demand dynamics are captured by a vector time series process that incorporates the stochastic co movements in price and demand we study two bwe measures one for each demand stream individually and one for the aggregated demand we show that demand parameters including demand autocorrelation cross correlation and price sensitivity serve as root causes of the bwe we prove that the impact of these parameters on the bwe can be additively decomposed conditions are established under which a pair of simultaneous compound causes may attenuate or dampen the bwe when demand streams are aggregated we derive a pooling factor that quantifies the impact of demand aggregation on order stability when positive the pooling factor corresponds to a synergy effect that captures the gain in the stability of the pooled orders conditions for the existence of the synergy effect are obtained for several special cases involving a zero leadtime we also discuss how our analytical findings can be managerially applied to bullwhip mitigation strategies

the effect of changes in the federal reserve s policy rule on the stochastic structure linking reserves interest rates and money in october 1979 the federal reserve announced a fundamental reform in its monetary control procedures 2 the alleged rationale for abandoning the old procedures utilized more or less continuously since 1970 was to improve the fed s control over the growth of the monetary aggregates the so called intermediate policy targets as often accompanies political and social reform the spectrum of criticism of the fed s alteration in procedures was wide this criticism ranged from the charge that the fed had gone too far or alternatively had regressed to ironically the charge that nothing had changed such competing contentions are in this case largely generated by the lack of incontrovertible evidence that monetary control improved after 1979 and the considerable increase in the volatility of interest rates which ensued

tangible and intangible sunk costs and the entry and exit of firms in a small open economy the case of austria the paper provides evidence on the role of sunk costs as mobility barriers an empirical study of the austrian manufacturing industry explicitly considers sunk costs related to investment in dedicated intangible assets the results confirm the relevance of sunk costs as mobility barriers their symmetry with respect to entry and exit and show that the influence of sunk costs is robust to aggregation

money demand instability has it ended abstract some researchers suggest that much of the seeming instability in the post 1973 money demand occurred because of financial innovation and deregulation money demand was in transition further unprecedented declines in the income velocity of circulation during 1985 and 1986 indicate that this hypothesized transition continues have the effects of financial innovation and deregulation run their course do additional unexpected shifts in velocity loom in the near future or has the transition come to a halt these questions are examined using the methodology of hafer and hein 1982 as modified by miller 1986 no evidence of structural shifts exists beyond 1986 m1 growth may have become a reliable monetary aggregate target again further the missing money has more than returned more money is held today than predicted by the pre 1973 money demand function since m1 now includes interest bearing transactions accounts and incorporates a saving motive the finding is not counterintuitive

outsourcing and capacity planning in an uncertain global environment firms employing offshore outsourcing strategies may face both exchange rate and demand uncertainties in this paper we show that the firms may benefit from operational option to switch production by keeping capacities with both domestic and foreign suppliers the value of the operational option increases as the exchange rate uncertainty or demand uncertainty increases in addition when the firms become risk averse they may use domestic capacity to hedge against offshore capacity as a result the firms may choose to hold local capacity even if it exhibits negative marginal contribution to the profit furthermore risk averse firms may keep more total capacity than risk neutral firms

cross country estimates of the demand for money and its components the demand for money aggregates m1 m2 and their components currency demand deposits and time deposits are estimated using a sample of 103 countries at two time periods money demand is found to be affected by age literacy industrial development and political structure as well as income and inflation this expanded demand function helps to explain the considerable changes in money demand that have occurred over long periods and the large variation in money demand found across countries the knowledge thus gained is useful for understanding differences in monetary and taxation policies across countries

sunk costs profit variability and turnover i introduction the dynamic competitive approach to the study of industrial organization highlights the role of sunk costs and the associated hysteresis effects in determining how industries behave over time the theoretical models are inherently difficult commenting on his own work jovanovic 1982 651 remarked that a curious feature of the paper is that proofs of obvious results are complicated such complexity precludes a canonical dynamic competitive model but favors the development of various models focusing on different aspects of reality in spite of this the dynamic competitive approach has yielded some predictions that are intuitively compelling and consistent with a variety of dynamic competitive models two such predictions are the focus of this article industries exhibiting higher sunk costs should also exhibit greater intertemporal variability of firm level profit and lower intertemporal variability in the number and identity of active firms examples of models that are broadly supportive of these predictions include those by dixit 1989 lambson 1991 1992 and hopenhayn 1992 dixit 1989 developed a continuous time model of a single firm facing an exogenous output price that follows a geometric brownian motion if entry costs are sunk then the firm s entry provoking price say alpha exceeds the firm s exit provoking price say omega furthermore alpha is increasing and omega is decreasing in the sunk cost suggesting that the range of profit is greater if sunk costs are higher this firm level model is poorly suited for studying industry level questions of entry and exit but caballero and pindyck 1996 considered an industry level extension of dixit s model 1989 657 58 and concluded that higher sunk costs increase the variability of the output price and hence of profit and decrease turnover lambson 1992 constructed a discrete time model of an industry that is subjected to exogenous stochastic shocks that are common to the firms such shocks might include changes in input prices demand conditions and the regulatory environment among others firm values above the entry cost xi induce entry whereas firm values below the scrap value chi induce exit the intertemporal range of firm values is thus approximately xi chi which is also a natural definition of sunk costs in the model with the intertermporal range of firm value being thus identified with sunk cost if the range of current profit is positively related to the range of firm values then the range of profit will be higher in high sunk cost industries yielding the first prediction less obvious but no less true in this model is the proposition that the intertemporal range of the number of active firms will be lower in high sunk cost industries lambson 1991 allows for endogenous heterogeneity because entering firms pay a sunk cost to install one of several available technologies this generates simultaneous entry and exit when for example there is a large change in relative input prices general proofs are lacking but examples suggest that higher sunk costs will tend to coexist with higher variability of profit and lower turnover hopenhayn 1992 modeled an industry in discrete time where firms are buffeted by idiosyncratic shocks to their productivity firms that suffer a series of negative shocks suffer such a decrease in their productivity that they find it optimal to exit the market the productivity level that triggers exit is lower when the entry cost is higher the lower trigger level implies a lower rate of turnover it also implies that a firm s profit can be lower without provoking exit this suggests that high sunk cost industries will exhibit more variability in firm level profits over time ii empirical precedents section i reviews two predictions from the theoretical literature using dynamic competitive models intertemporal profit variability should be higher in higher sunk cost industries and turnover should be lower in higher sunk cost industries

structural changes and the us money demand function previous literature on the stability of the us money demand function suggests mixed results in this article we study the stability of the money demand function from the standpoint of structural changes in the function we first investigate if a stable money demand function can be found for the us for the period from the first quarter of 1959 to the fourth quarter of 2000 the results show that a stable long run money demand function does not exist for the sample period under consideration we then estimate unknown structural break points in the variables of the money demand function using bai and perron s 1998 method and test if there is a stable relationship in each sub sample period of the break points the results show that a stable relationship exists for each sub sample period the estimated income elasticity and interest rate semi elasticity are relatively smaller than ball s 2001 estimates but consistent with his argument

modeling the demand for narrow money in the united kingdom and the united states abstract despite the importance of well specified empirical money demand functions for inference forecasting and policy problems in modeling have arisen concerning the economic theories of money demand the data institutional frameworks financial innovation and econometric implementation by developing constant data coherent m 1 demand equations for the u k and the u s we investigate these issues and explain such puzzles as missing money the great velocity decline and the recent explosion in m 1 the endogeneity of money the lucas critique and the non invertibility of our m 1 models are also discussed

determining the optimal size of supply base with the consideration of risks of supply disruptions abstract determining the optimal size of the supply base has haunted managers for years a small supply base gives rise to the risk of supply disruption whereas a large supply base increases the fixed cost in this paper we consider the risks of supply disruption due to occurrence of super semi super and unique events in order to formulate a model to determine the optimal size of supply base we depict the model in a decision tree like structure and forward a tabular method of solution that obviates the need avoids evaluation of a majority of non optimal solutions and thus overcomes the problem of dimensionality

the scourge of the monetarists kaldor on monetarism and on money nicolas kaldor s critique of monetarism from 1970 until his death is described and evaluated it is argued that subsequent events as well as empirical research vindicate his critique kaldor s critique of john maynard keynes s monetary theory is then seen as an extension of his radcliffe views and this paper argues that in this matter kaldor was mechanical in his modeling of the endogeneity of money supply it is suggested that the work of hyman minsky and victoria chick has the potential for further work in this area copyright 1989 by oxford university press

the money supply process under alternative federal reserve operating procedures an empirical examination increasing reliance on the monetary aggregates as indicators of economic activity in conducting monetary policy led the federal reserve to change its operating procedure in october 1979 in an attempt to gain greater control over the monetary aggregates the fed switched from using the federal funds rate as its operating instrument to operating by means of nonborrowed reserves subsequent increased volatility in interest rates coupled with sharp fluctuations in money growth and economic activity led the fed to modify its procedure once more in the autumn of 1982 switching its operating target from nonborrowed to borrowed reserves this paper examines empirically the money supply process from 1970 to 1986 we find that the process itself was not invariant to the fed s changes in operating procedure thus the effect of these changes did not lead to more or less control of money by the fed under the same money supply process rather the changes in the fed s procedure led to changes in the money supply process which in the case of the first change in procedure at least largely thwarted the aims of the fed regarding money control we show that the switch to a reserves operating procedure which has since been modified but not completely abandoned has failed to overcome the short run endogeneity or demand determination of money which the fed had experienced prior to october 1979 because the banking system has changed its behavior with respect to the link between reserves and money supply under the newer procedure

speculative production and anticipative reservation of reactive capacity by a multi product newsvendor in this paper the optimal sourcing decisions of a multi product newsvendor prior to the selling season of the products are studied to satisfy the uncertain demands the newsvendor can either utilize speculative production or anticipatively reserve capacity during the selling season when demand has become known the newsvendor can utilize its reserved capacity and reactively satisfy demand uncovered by its speculative production for the case where capacity for speculative production may be limited but potential reservation of reactive capacity is unlimited two capacity reservation settings are analyzed and compared in the first one capacity for each product has to be reserved separately while in the second setting one joint capacity reservation for all products is permitted which can then be allocated to the different products optimally during the selling season for the case of separate individual reservations the optimal strategies are analytically derived and structural insights concerning their existence are presented as the model allowing for joint reservation can not be tackled analytically in general an approximation based on an lp formulation is used through a numerical example insights on the value of the increased flexibility induced by joint reservation the cost premium acceptable for joint reservation and the relative levels of capacity reservation in the two settings are given

new concepts of aggregated money the federal reserve board s recent redefinition of its monetary aggregates followed three years of intensive board staff research on monetary aggregation while the new aggregates ultimately were selected along conventional lines some of the staff s research was oriented towards more fundamental changes in monetary aggregation methods this paper reviews such proposals which are based upon the rigorous application of index number and aggregation theory and of principal components analysis in the construction of economic monetary aggregates the usefulness of aggregation and index number theory in acquiring price indices is widely known the theory of the true cost of living index is an application of aggregation theory examples of applied index number theory include the commerce department s implicit price deflator which is a paasche index and the labor department s consumer price index which is a laspeyres index somewhat less well known is the fact that dual to the theory of economic price aggregates and indices is a theory of economic quantity aggregates and indices an example of a highly reputable quantity index is the divisia quantity index the monetary aggregates traditionally are thought to measure the supplied quantity of an economic good called money whenever monetary aggregates are used in the context of economic theory rather than as simple accounting identities the theory of economic quantity aggregation is specifically applicable however published monetary aggregates in all countries have always been computed as simple sums but as fisher 1922 p 29 observed in the conclusion to his classic treatise on index number theory the simple arithmetic average produces one of the very worst of index numbers and if this book has no other effect than to lead to the total abandonment of the simple arithmetic type of index number it will have served a useful purpose with an example of the simple sum index fisher 1922 p 363 found that the bias alone reaches 36 percent although index number theory has not yet found its way into the monetary theory literature all of the literature on index number theory and aggregation theory for the past half century supports the result long ago deduced by fisher 1922 p 361 that the simple arithmetic index should not be used the views expressed herein are solely those of the authors and do not necessarily represent the views of the board of governors of the federal reserve system this research was partially supported by national science foundation grant soc 76 84459 we are deeply indebted to the conference session s discussant of this paper w erwin diewert for volunteering to cede his allocated journal space to us so that the paper could take its current extended form federal reserve board washington d c

diversification under supply uncertainty supply chain management is becoming an increasingly important issue especially when in most industries the cost of materials purchased comprises 40 60 of the total sales revenue despite the benefits cited for single sourcing in the popular literature there is enough evidence of industries having two three sources for most parts in this paper we address the operational issue of quantity allocation between two uncertain suppliers and its effects on the inventory policies of the buyer based on the type of delivery contract a buyer has with the suppliers we suggest three models for the supply process model i is a one delivery contract with all of the order quantity delivered either in the current period with probability or in the next period with probability 1 model ii is also a one delivery contract with a random fraction of the order quantity delivered in the current period the portion of the order quantity not delivered is cancelled model iii is similar to model ii with the remaining quantity delivered in the next period we derive the optimal ordering policies that minimize the total ordering holding and penalty costs with backlogging we show that the optimal ordering policy in period n for each of these models is as follows for x a n order nothing for vi n x a n use only one supplier and for x vi n order from both suppliers for the limiting case in the single period version of model i we derive conditions under which one would continue ordering from one or the other or both suppliers for model ii we give sufficient conditions for not using the second more expensive supplier when the demand and yield distributions have some special form for the single period version of models ii and iii with equal marginal ordering costs we show that the optimal order quantities follow a ratio rule when demand is exponential and yields are either normal or gamma distributed

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

diversification under yield randomness in inventory models abstract in this paper we consider the case of random yield and diversification in two different inventory models it is assumed that two sources suppliers exist who ship an amount which is a random function of the amount requisitioned since they may charge different prices and their reliability in terms of the variance of the yield random variable may be different diversification may be more desirable than using a single supplier we analyze this problem for both the eoq model and the newsboy model analytic results for the optimal order quantities and the minimum cost are obtained for the eoq model convexity of the objective function is also discussed we develop the necessary conditions for the newsboy model and propose an approximate solution technique the concavity of the expected profit function is shown numerical examples are provided for both models

cointegration and structural change an application to the u s demand for money wankeun oh i perform the cointegration tests for the trivariate model of real monetary aggregates real personal income and short term interest rate i find the existence of a long run relationship among these three variables to check the stability of a long run money demand relationship i implement a rank constancy test and cusum test the test results show that real mi is relatively more stable than other aggregates but structural change occurred during the 1970s and early 1980s this is consistent with prior research on money demand jel e41 i introduction incorporating structural change when performing tests on the properties of stochastic processes is important because structural breaks may cause misspecification problems most tests of structural change consider the stability of the parameters over time tests for structural breaks and parameter stability have been studied extensively a partial list includes chow 1966 brown et al 1975 harvey and collier 1977 king 1987 ploberger et al 1989 in the context of unit root processes perron 1989 showed that the presence of a one time change in the level or slope of the trend function can severely distort the results of unit root tests and it is natural to ask how structural change can distort the results of cointegration tests 1 traditional tests of parameter stability ask if the parameters of the model are constant in contrast quintos 1993 proposed a test for stability of the long run relationship s in a cointegrating regression the test is based on johansen s 1988 framework and the test statistic is simply the weighted sum of the likelihood ratio test as given in johansen 1988 quintos s rank test is very different from the traditional cusum and chow tests for parameter stability because her rank test checks for stability of the cointegrating relationship between variables in other words the rank test checks whether cointegration holds for the full period the traditional cusum and chow tests assume that cointegration holds for the full period or does not hold for the full period and tests simply whether the cointegration vector changes for example if there is cointegration from 1960 1990 between revenues and expenditures with cointegrating vector 1 1 then the cusum and chow tests check whether the cointegra ting vector 1 1 is stable throughout the period the rank constancy test checks whether the cointegration rank is stable throughout the period not whether the cointegrating vector is stable at 1 1 in other words the rank test will check whether for example there is cointegration from 1960 1980 and no cointegration from 1980 onward the chow and cusum tests are not designed to check for this the structural stability of money demand relationships has been the issue of a substantial number of empirical studies 2 in general structural stability means stability of the underlying behavioral equations 3 this term includes parameter stability and stability of functional form friedman s 1990 research on the money demand function assumes that a long run equilibrium relationship exists between real money balances real income or real wealth and the opportunity cost of holding real money balances recently there has been strong evidence of cointegration between real income real money balances and a nominal interest rate for instance engle and granger 1987 dickey et al 1991 hafer and jansen 1991 hoffman and rasche 1991 mehra 1993 miller 1991 fischer and nicoletti 1993 and baba et al 1992 report on cointegration among variables in u s aggregate money demand jain and moon 1994 report on cointegration in u s sectoral money demand yashiv 1994 and engsted 1993 on money demand in a high inflation country and hoffman et al 1995 report on international money demand comparison this article asks if long run money demand relationship is stable and if so for which measure of money is it stable over time

finance capital in dynamic factor demand models the lagged partial adjusment money demand function has been studied theoretically and empirically for the aggregate economy this paper focuses on a sectoral analysis of two partial adjustment functions one for optimal money demand and another for optimal loans demand the two partial adjustment equations are derived employing a representive firm approach a dynamic factor demand model with internal costs of adjustment is utilized to generate euler equations for the demand for money and short term business loans these euler equations parallel the aggregate partial adjustment money demand equations typically employed in applied monetary research the significant difference between the ad hocderivation and the microtheoretic derivation employed here is that desired money and loan holdings are found by solving the euler equations these particular definition of desired money and loan holding are model consistent and depend upon the predetermined and exogeneous variables of the model empirical analysis ge

an exact algorithm for the capacitated total quantity discount problem in this paper we analyze the procurement problem of a company that needs to purchase a number of products from a set of suppliers to satisfy demand the suppliers offer total quantity discounts and the company aims at selecting a set of suppliers so to satisfy product demand at minimum purchasing cost the problem known as total quantity discount problem tqdp is strongly np hard we study different families of valid inequalities and provide a branch and cut approach to solve the capacitated variant of the problem capacitated tqdp where the quantity available for a product from a supplier is limited a hybrid algorithm called help heuristic enhancement from lp is used to provide an initial feasible solution to the exact approach help exploits information provided by the continuous relaxation problem to construct neighborhoods optimally searched through the solution of mixed integer subproblems a streamlined version of the proposed exact method can optimally solve in a reasonable amount of time instances with up to 100 suppliers and 500 products and largely outperforms an existing approach available in the literature and cplex 12 2 that frequently runs out of memory before completing the search

macroeconomic disequilibrium structural changes and the household savings and money demand in china abstract this paper presents an empirical study of the chinese personal money demand and savings in an economy of disequilibrium and structural changes we propose specifications capable of encompassing and testing the two competing hypotheses which have been advanced to explain the case of the chinese household money demand and savings based on the national and provincial data we find that both repressed inflation and structural changes are significant suggesting the need to capture both the possible disequilibrium and structural shifts further statistical evidence shows that there might have been multiple regime shifts during the post 1949 period which is at variance with the conventional approach of exclusive focus of the effects of the recent reforms nesting the competing hypotheses appears to be the key in providing an adequate account of the savings and money demand of the chinese household sector the evidence seems to favor the repressed inflation hypothesis

recent instability of the demand for money an international perspective aggregate money demand functions once an apparent bulwark for macroeconomic research have had to be re examined in the light of the events and discoveries of the 1970s following goldfeld s extensive analysis it now is widely recognized that the demand for mi balances in the united states cannot be explained satisfactorily by standard functions apparently because of shifts occurring in the early 1970s similar reservations see below have been expressed with respect to m3 balances in the united kingdom where the demand relationships appear to have been upset by the introduction of regulatory reforms in 1971 in both cases part of the problem can be traced to specific events but the possibility remains that a more general instability may be present the rapid inflation experienced by all major industrial countries after 1973 the concurrent collapse of the bretton woods system of fixed exchange rates and the attempts by most major central banks to control growth in domestic money stocks may all have altered the responses of the demand for money to the standard functional arguments this paper presents a range of stability tests for a set of demand functions estimated for two monetary aggregates in each of six countries in order to determine whether money demand functions more generally have been stable over the recent period and to attempt to identify the nature and causes of any observed instabilities the major conclusions are that none of the other functions examined displays instabilities as severe as those of the mi function for the united states and that the latter may be unstable in a more persistent and fundamental way than has heretofore been recognized the equations estimated for this study are based on a variant of goldfeld s log linear real balances function the deflated value of money balances is related to real income interest rates and inflation with lagged adjustments introduced via a simple koyck transformation this function obviously is in a simplified form especially with respect to the lag struc

short run money demand abstract the conventional wisdom holds that the short run demand for money is unstable this paper challenges the conventional view by finding a stable demand for m1 in u s data from 1959 through 1993 the approach follows previous work in interpreting long run money demand as a cointegrating relation and it uses goldfeld s partial adjustment model to interpret short run dynamics the key innovation is the choice of the interest rate in the money demand function most previous work uses a short term market rate but this paper uses the average return on near monies the savings accounts and money market mutual funds that are close substitutes for m1 this choice helps rationalize the behavior of money demand in particular the increase in the volatility of velocity after 1980 is explained by increased volatility in the returns on near monies

regression direction and weak exogeneity abstract the absence of testing for weak exogeneity in money demand has often led to stark conditioning claims regarding the validity of price equations this paper uses the johansen procedure to explore the conditioning properties of money demand systems for nonborrowed reserves m1 and m2 our results show that irrespective of the specification of the cointegrating relation a feedback mechanism enters the equation for money the opposite however is not true for the price equations the results also cast a warning for single equation models of money demand in that weak exogeneity is sensitive to how the system is defined

money and credit confused an appraisal of economic doctrine and federal reserve procedure it is a serious error to suppose that if the monetary authorities are to alter the actual quantity of money people must first be persuaded through interest rate movements to alter the quantity of money they wish to hold nevertheless the error in one guise or another pervades the literature on monetary policy as a result of the fed s willingness to prevent or moderate a demand induced movement in the interest rate write lombra and kaufman 16 1156 in this very journal shifts in money demand cause shifts in the same direction in reserve supply and therefore money supply econometrically determined money supply functions are thus not what they

ordering and production decisions with supply quality and demand uncertainty in this paper we solve a production planning problem that has a direct bearing on the cost to a facility of vendor quality and reliability this solution is also an important first step in solving the multi plant coordination problem we consider a manufacturing facility with one critical raw material and one or more products whose demand needs to be met it is assumed that demand for finished goods and the arrival process for raw material are stochastic we calculate simultaneously the optimal production level and the raw material order quantity which minimize the total expected cost subject to capacity and release level constraints the results obtained by our model the integrated model show that the production level should be no larger than the production level obtained by solving the traditional nonintegrated models and that major savings are obtained by solving the integrated model we are also able to characterize and evaluate the cost of reliable supplies of raw material in addition we solve the above problem in the presence of capacity constraints a procedure which allocates capacity to different products is presented

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

the money supply process identification stability and estimation questions regarding the structure and stability of money demand and money supply functions lie at the heart of many unresolved issues in macroeconomics in general and monetary theory and policy in particular general recognition of the problem probably accounts in part for what appears to be an insatiable appetite of the major journals for papers on money demand and money supply among the many issues addressed in the recent literature the stability of money demand has perhaps attracted the most attention an unsettling characteristic of all the tests for stability has been an underlying often implicit assumption that the money supply has been exogenously determined by the central bank the presumed exercise of federal reserve control over the money supply so as to make it statistically independent of disturbances is in turn predicated on the twin premises that the money supply function is in itself structurally stable and in addition is independent of fluctuations in money demand 2

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

on cash in advance models of money demand and asset pricing this paper shows how a cash in advance model of money can be written in a way that combines a simple yet empirically defensible money demand function with an asset pricing equation that is similar to the standard barter economy euler equations return premia are determined as in the barter exchange model except that a short term risk free nominal interest rate enters into the first order conditions in special cases asset prices satisfy the barter economy euler equations exactly in the empirical analysis the interest rate factor adds some explanatory power but both the barter and the monetary asset pricing model perform rather poorly copyright 1991 by ohio state university press

unstable money demand and the monetary model of the exchange rate in this paper the authors investigate the importance for the monetary model of exchange rate determination of j frankel 1979 of allowing unrestricted dynamics and of accounting for shifts in the demand for money due to financial innovation based on estimation and simulation results for the canada u s bilateral exchange rate over the 1970 85 period the aut hors find strong evidence in favor of a generalized approach to dynamic specification but find that the shif t adjustment of official money supply data has only minor implications for the empirical results moreover neither modification is sufficient to generate a monetary model that is well supported by the data

sweep programs the fall of m1 and rebirth of the medium of exchange this paper investigates the effect of sweep programs on m1 using dynamic simulations of money demand over 1994 2000 the postsample period constitutes when sweep programs have been in effect all models generate predictions systematically above reported m1 using data on newly initiated programs test findings indicate that sweeps account for the overprediction within the conventional money demand model with a long term interest rate we construct a medium of exchange measure m1s equal to m1 plus estimated holdings of sweep balances m1s velocity compares favorably with that of broader aggregates evidence indicates cointegration within m1s money demand

caution and conservatism in the making of monetary policy does society benefit from the delegation of monetary policy to cautious and conservative central bankers we offer a critical view on the delegation literature and relax seemingly innocuous assumptions about uncertainty and preferences first caution improves credibility but does not obviate the need for central bank conservatism second previous models of delegation have focused on suboptimal forms of conservatism we derive optimal concepts of conservatism that mitigate or eliminate any residual problem of credibility third we rationalize why credible monetary policy may be conducive to stable inflation and output

are price equations really money demand equations on their heads it is often argued that the dependent variable in money demand functions is really the price level the money stock itself being exogenous a recent approach which stresses the theme is the buffer stock hypothesis in which money supply shocks explicitly appear in the demand for money function because prices and interest rates do not adjust rapidly enough to bring about short run equilibrium in the money market although this approach has been adopted by a number of authors it is not been subjected to much econometric testing in this paper we outline the economic and econometric issues involved in testing the exogenous money buffer stock hypothesis and subject it to a variety of tests using three different data sets none of our results supports the hypothesis fundamental restrictions are rejected at very high levels of significance and a reasonably good money demand equation is seen to be badly misspecified if interpreted as a price equation this abstract was borrowed from another version of this item

sunk costs and the variability of firm value over time empirical implications for the variability of firm value in various models of industry evolution are discussed under certain conditions learning models imply that industries with higher sunk costs should exhibit greater difference in firm value between entering and exiting firms whereas external shocks models imply that industries with higher sunk costs should exhibit greater variability of firm value over time relative to a numeraire industry the theoretical results from external shocks models are consistent with agricultural data from california and florida copyright 1995 by mit press

single versus multiple supplier sourcing strategies successful supply chain management necessitates an effective sourcing strategy to combat uncertainties in both supply and demand in particular supply disruption results in excessive downtime of production resources upstream and downstream supply chain repercussions and eventually a loss in the market value of the firm in this paper we analyze single period single product sourcing decisions under demand uncertainty our approach integrates product prices supplier costs supplier capacities historical supplier reliabilities and firm specific inventory costs a unique feature of our approach is the integration of a firm specific supplier diversification function we also extend our analysis to examine the impact of minimum supplier order quantities our results indicate that single sourcing is a dominant strategy only when supplier capacities are large relative to the product demand and when the firm does not obtain diversification benefits in other cases we find that multiple sourcing is an optimal sourcing strategy we also characterize a non intuitive trade off between supplier minimum order quantities costs and supplier reliabilities finally we examine the robustness of our results through an extensive numerical analysis of the key parameters of our model

the persistence of interest rate effects on the demand for currency note since the end of world war ii there has been a trend decline in the demand for real currency balances part of the decrease is due to the rise in interest rates to unprecedented heights yet this is not the complete answer since a trend term included in a simple and conventional currency demand equation that already includes an interest rate still emerges with a significant negative coefficient for example using quarterly data from 1950 i to 1981 iii a demand for currency equation can be estimated as

newsvendor competition under asymmetric cost information abstract we study the newsboy duopoly problem under asymmetric cost information we extend the lippman and mccardle 1997 of competitive newsboy to the case where the two firms are privately informed about their unit costs the market demand is initially split between two firms and the excess demand for each firm is reallocated to the rival firm we show the existence and uniqueness of a pure strategy equilibrium and characterize its structure the equilibrium conditions have an interesting recursive structure that enables an easy computation of the equilibrium order quantities presence of strategic interactions creates incentives to increase order quantities for all firm types except the type that has the highest possible unit cost consequently competition leads to higher total inventory in the industry however contrary to intuition this is only true when the firms are non identical a firm s equilibrium order quantity increases with a stochastic increase in the total industry demand or with an increase in his initial allocation of the total industry demand we demonstrate our model and results in an application in a dual sourcing procurement setting using data that obtained from a large manufacturing company finally we provide a full characterization of the equilibrium of the game for the special case of uniform demand and linear market shares

bilateral investment treaties and fdi does the sector matter summary developing and transition countries have increasingly engaged in the signing of bilateral investment treaties bits in order to attract fdi based on the widely shared view that fdi can contribute significantly to economic development and poverty reduction however the degree to which foreign investments can be expected to generate employment offer access to international technology and know how and ultimately create growth varies considerably depending on the type of investment it is therefore important to determine what type of fdi is attracted by bits by providing a legal commitment to the fair and equitable treatment of foreign investors bits aim to decrease investment risk and to attract foreign investors we argue that bits can be expected to be most effective in those sectors of the economy with a larger risk of expropriation i e sectors characterized by large sunk costs relatively low levels of firm specific know how and in sectors that are politically sensitive to foreign ownership this paper represents the first attempt to empirically study the heterogeneous effect that bits may have across different sectors of investments we analyze investments made in 13 countries in the former soviet union and central and eastern europe disaggregated over seven sectors we indeed find the effect of bits to differ considerably across sectors of investment using capital intensity as a proxy we confirm that fdi in those sectors with higher sunk costs responds more strongly to the signing of bits given the considerable differences in the development impact that can be expected from fdi in different sectors it remains to be shown whether bits are an effective tool to attract those types of investments that are most beneficial for the development of the host economy

the effects of sunk costs on entry and exit evidence from 36 countries abstract dynamic competitive models of industry evolution suggest that intertemporal variability of the number of firms should be lower in industries with higher sunk costs we test this proposition using data from 36 countries the results are consistent with the theory

a closer look at long run u s money demand linear or nonlinear error correction with m0 m1 or m2 i introduction the stability of money demand has been a long standing issue 1 lucas 1988 informally analyzes the stability of a log linear m1 money demand function and concludes that real money demand is a stable function and he supports earlier findings of meltzer 1963 with an income or wealth elasticity of around unity 2 with the development of cointegration methods engle and granger 1987 numerous empirical studies have applied these techniques to long run u s money demand examples are baba hendry and starr 1992 haferand jansen 1991 hoffman and rasche 1991 and miller 1991 who find support for a cointegrated money demand model with either m1 or m2 3 king et al 1991 also find support for cointegration with m2 and a short term interest rate in contrast to these studies others have argued against a stable u s money demand function in the postwar period for example friedman and kuttner 1992 do not find support for cointegration particularly when the period march 1970 to april 1990 is considered similarly miyao 1996 studies the behavior of the m2 money demand function over the period from 1959 to 1993 with quarterly data and various interest rates in levels and in logs miyao concludes that m2 is not a useful intermediate target for monetary policy in the 1990s 4 however carlson et al 2000 reach the conclusion that m2 does have predictive content for nominal economic activity and that the real m2 money demand function is stable but only after accounting for financial innovation in the first half of the 1990s two recent papers ball 2001 and stock and watson 1993 focus on especially long data sets for the united states and m1 stock and watson 1993 analyze various estimation methods for cointegrating relationships and illustrate their performance for money demand functions with annual data from 1900 to 1987 they pay particular attention to the postwar period and use monthly data in addition to annual data for this period they employ a semi log linear real m1 money demand model with real net national product and the level of the 6 mo commercial paper rate for the postwar period they also consider the 90 day treasury bill rate and the 10 yr treasury bond rate they compare and contrast their results to those of various others they also carry out recursive estimations to check their results for stability stock and watson 1993 conclude that a long span of data is needed to estimate long run money demand functions precisely their overall evidence is in favor of a stable long run money demand function with an income elasticity near one and an interest rate semielasticity near 0 10 however the postwar data are found to be not very informative a lack of low frequency variation in the postwar data as suggested by lucas 1988 does not allow a disentangling of the effects of output and interest rates on money demand for this time period estimates are imprecise and sensitive to subsample specifications due to substantial colinearity ball 2001 revisits the m1 money demand model of stock and watson 1993 using the same data set but extended through 1996 he applies the same array of estimation techniques as stock and watson did ball obtains precise estimates over the postwar period for his extended data set an income elasticity of approximately 0 5 and a semielasticity of 0 05 for the interest rate he does not find support for a velocity specification the m1 model is not stable over the period 1900 1996 lutkepohl terasvirta and wolters 1999 apply a nonlinear error correction model with smooth transition adjustment to capture instabilities in the linear cointegration model the long run equilibrium is described by a linear cointegrating relation and the adjustment to this long run equilibrium is nonlinear they analyze german m1 money demand granger and terisvirta 1993 terasvirta 1998 and van dijk terasvirta and franses 2002 provide details on the econometric theory for estimating and testing such nonlinear models

sole versus dual sourcing in stochastic lead time s q inventory models when supply lead times are uncertain the simultaneous procurement from two sources offers savings in inventory holding and shortage costs economies are achieved if these savings outweigh the increase in ordering costs in this paper we analyze dual sourcing in the context of the reorder point order quantity inventory model with constant demand and stochastic lead times and compare it with single sourcing two cases are studied using the uniform and the exponential distributions which may be thought of as two extreme ways of representing stochastic lead times in our two vendor model the order quantity is split equally between the two vendors and the split orders are placed simultaneously when the inventory position reaches the reorder level a comparison of the total expected costs suggests that when the uncertainty in the lead times is high and the ordering costs are low dual sourcing could be cost effective

on the markov switching welfare cost of inflation abstract this paper uses the markov switching approach to account for instabilities in the long run money demand function and compute the welfare cost of inflation in the united states in doing so it circumvents the problem of data mining of some earlier seminal contributions on these issues allowing for complicated nonlinear dynamics and sudden changes in the parameters of the money demand function moreover it extends the sample period and investigates the robustness of results to alternative money demand specifications monetary aggregation procedures and assumptions regarding dynamics aspects of the money demand specification

the newsvendor problem review and directions for future research in this paper we review the contributions to date for analyzing the newsvendor problem our focus is on examining the specific extensions for analyzing this problem in the context of modeling customer demand supplier costs and the buyer risk profile more specifically we analyze the impact of market price marketing effort and stocking quantity on customer demand how supplier prices can serve as a coordination mechanism in a supply chain setting integrating alternative supplier pricing policies within the newsvendor framework and how the buyer s risk profile moderates the newsvendor order quantity decision for each of these areas we summarize the current literature and develop extensions finally we also propose directions for future research

a comparison among partial adjustment rational expectations and error correction estimates of the canadian demand for money starting from a dynamic optimization principle the currently most popular approaches to modelling money demand functions are derived the partial adjustment adaptive expectations rational expectations and error correction mechanism formulations are then estimated using a common data set the error correction mechanism equation is found to dominate the others either because their implicit restrictions are rejected rational expectations or by employing the encompassing principle partial adjustment adaptive expectations surprisingly all three forms have similar long run solutions since the short run dynamics differ substantially the results have important implications for the conduct of monetary policy

sunk costs firm size and firm growth for several decades the conventional wisdom has been that expected firm growth rates are independent of firm size a property known as gibrat s law however recent empirical work has found a negative relation between firm growth and firm size this paper provides a theoretical explanation for this negative relation in a model of new firm growth where capacity and technology choices involve some degree of sunkness additional empirical implications of the theory of sunk costs are also developed these relate to profit rates tobin s q exit rates degree of sunkness of capacity costs as well as size and growth rates copyright 1995 by blackwell publishing ltd

an experimental test of the baumol tobin transactions demand for money historically generated data do not allow a clean test of any particular money dema nd theory by creating the artificial environment analyzed by william baumol and james tobin s work on the transactions demand for money one can observe how real people pursuing real rewards behave in that environment baumol and tobin assumed people were sufficiently rational to learn four axioms of rational behavior the authors subjects learned only three however trial and error methods plus subjects limited rationality did produce results similar to the baumol tobin predictions this supports the need to weaken the definition of rationality in the manner suggested by herbert simon copyright 1988 by ohio state university press

unanticipated money growth and unemployment post sample forecasts in the late 1970s robert j barro published what has since become a popular model of business fluctuations barro s 3 findings provide evidence advocating the short run neutrality of money under rational expectations forging an important empirical link to the theoretical studies of lucas 19 20 and sargent and wallace 33 the original barro unemployment model has received additional support from further statistical testing 5 6 15 despite criticisms and modifications some of which are considered in barro s 6 updated model these equations have inspired numerous empirical studies analyzing unanticipated effects of macroeconomic variables this paper examines post sample forecasts of barro s original 3 and revised 6 unemployment equations for the 1974 84 period mayer 23 24 harvey 13 179 80 and lovell 18 among many contend that the ability to successfully forecast outside of the sample period is an important criterion for evaluating model robustness this view is also reflected in a substantial body of studies including 10 25 26 29 39 which investigate the post sample predictive performance of macroeconomic models one year ahead forecasts indicate that the barro 3 6 equations accurately predict unemployment for the 1974 79 period during 1980 84 however the predictive performance of both models sharply deteriorates augmenting the barro models with interest rate volatility in accordance with the findings of evans 11 and tatom 38 considerably improves the overall forecasting ability this modification also rectifies the 1980s structural instability of the barro unemployment equations furthermore the basic conclusions of the seminal barro work are retained with this augmented model the results reveal that increases in interest rate volatility exert significantly adverse effects upon unemployment corroborating with the findings of evans 11 and tatom 38 still interest rate volatility could be overlooked in previous estimations of the barro or other models of business fluctuations due to the variable s relative constancy prior to 1979

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

international evidence on misspecification of the standard money demand equation abstract this paper tests the proposition that the interest rate in the standard money demand equation acts as a proxy for the expected change in interest rates if this is true the interest elasticity in the standard equation will depend on the expectations process for interest rates using cross country data we find that there does exist a relationship between the observed interest elasticity in the standard equation and the predictability of future interest rates from current interest rates

demand side reactive strategies for supply disruptions in a multiple product system abstract this research examines demand side reactive strategies for supply disruption in a multiple assemble to order system we consider an assemble to order system with two substitute products where the demand is price sensitive and disruption sensitive two different supply disruption situations are examined disruption of the low value component and disruption of the high value component we propose and compare the performance of four reactive strategies for managing supply disruptions namely the backordering strategy the upgrading downgrading strategy the compensation strategy and the mixed strategy we find that the compensation strategy and the mixed strategy can keep more customers than the backordering strategy and the upgrading strategy during the supply disruption of the low value product for the disruption of the high value product the total number of customers keeps constant but it does lead to the reallocation of customers among the products we find that the mixed strategy is the best reactive strategy and the backordering strategy is the worst one among the four reactive strategies