the changing empirical definition of money a comment in a recent issue of this journal belongia and chalfant 1989 suggested that several groups of financial assets formed monthly economic monetary aggregates from january 1983 through february 1986 they based these findings on nonparametric revealed preference tests developed by varian 1982 1983 they implemented these tests using nominal assets data implementing these tests with nominal data is inconsistent with a neoclassical framework of consumer choice based on real variables we find that their use of nominal data led belongia and chalfant to obtain results different from those they would have obtained if they had used real assets data we reran their tests using real data and found that none of the monetary aggregates they identified can be shown to be consistent with the existence of an economic aggregate

measuring the impacts of teachers reply abstract rothstein 2017 successfully replicates chetty friedman and rockoff s 2014a b henceforth cfr s results using data from north carolina but raises concerns about cfr s methods we show that rothstein s methodological critiques are invalid by presenting simulations and supplementary empirical evidence which show that i his preferred imputation of missing data generates bias ii his placebo test rejects valid research designs and iii his method of controlling for covariates yields inconsistent estimates of teachers long term effects consistent with the conclusions of bacher hicks kane and staiger 2016 using data from los angeles we conclude that rothstein s replication study ultimately reinforces cfr s methods and results jel h75 i21 j45

financial firm production of monetary services a generalized symmetric baroett variable profit function approach an alternative monetary production model of financial firms is employed to investigate supply side monetary aggregation financial firms are conceived to produce monetary services as outputs through financial intermediation a new method for testing the existence of consistent monetary output aggregates in financial firms production technology is developed in terms of a multiproduct firm s variable profit function and the method does not require homotheticity of the aggregator function we use a generalized symmetric barnett flexible functional form that specification satisfies global curvature conditions and retains its flexibility under the null hypothesis of weak separability neither of those properties is possessed by other flexible functional forms

teacher quality in educational production tracking decay and student achievement growing concerns over the inadequate achievement of u s students have led to proposals to reward good teachers and penalize or fire bad ones the leading method for assessing teacher quality is value added modeling vam which decomposes students test scores into components attributed to student heterogeneity and to teacher quality implicit in the vam approach are strong assumptions about the nature of the educational production function and the assignment of students to classrooms in this paper i develop falsification tests for three widely used vam specifications based on the idea that future teachers cannot influence students past achievement in da ta from north carolina each of the vams exclusion restrictions are dramatically viola ted in particular these models indicate large effects of 5th grade teachers on 4th grade t est score gains i also find that conventional measures of individual teachers value added fade out very quickly and are at best weakly related to long run effects i discuss implic ations for the use of vams as personnel tools

the changing empirical definition of money some estimates from a model of the demand for money substitutes interest bearing checkable deposits are examined to test whether they should be included in measures of the u s money stock both divisia and traditional simple sum aggregates are constructed on the basis of tests for weak separability in a model of the demand for financial assets using nonparametric demand analysis we find that several groups of assets are compatible with aggregation theory we find empirical support for a narrow measure consisting of the components of current mia in tests based on a st louis equation and in terms of controllability a divisia aggregate performs better than the simple sum mia measure

using lagged outcomes to evaluate bias in value added models abstract value added va models measure agents productivity based on the outcomes they produce the utility of va models for performance evaluation depends on the extent to which va estimates are

measuring the impacts of teachers i evaluating bias in teacher value added estimates are teachers impacts on students test scores value added a good measure of their quality one reason this question has sparked debate is disagreement about whether value added va measures provide unbiased estimates of teachers causal impacts on student achievement we test for bias in va using previously unobserved parent characteristics and a quasi experimental design based on changes in teaching sta using school district and tax records for more than one million children we nd that va models which control for a student s prior test scores exhibit little bias in forecasting teachers impacts on student achievement although teachers have substantial impacts

exchange rates financial innovation and divisia money the sterling dollar rate 1972 1990 in this paper we examine the usefulness of divisia money relative to simple sum money for exchange rate modelling in a period of rapid financial deregulation this comparison is conducted using as a convenient framework the monetary model of the exchange rate we demonstrate inter alia that for the sterling us dollar exchange rate over the period 1972 q1 to 1990 q2 that the use of divisia money makes a significant difference to both the long and short run modelling of the exchange rate

money demand variability a demand systems approach this article tests the fourier flexible form on quarterly u s monetary data the data have been prescreened for consistency with the general axiom of revealed preference and subindexes are formed using the divisia approach in this article the global fourier model fits well although there is a potential problem of overfitting and certain data points exhibit behavior inconsistent with the model the elasticities are variable over time particularly around business cycle troughs it appears that financial asset demand surfaces are highly nonlinear and the many unsuccessful existing attempts to estimate money demand may not have worked well for this reason

real and monetary determinants of real exchange rate behavior theory and evidence from developing countries abstract this paper develops a dynamic model of real exchange rate rer behavior in developing countries a three goods economy exportables importables and non tradables is considered residents of this country hold domestic and foreign assets and there is a dual exchange rate regime there is a government that consumes importables and non tradables a distinction is made between equilibrium and disequilibrium movements of the rer the determinants of real exchange rate misalignment are studied with emphasis placed on the role of devaluations and balance of payments crises the implications of the model are tested using data for 12 developing countries the results obtained are generally favorable for the model the issue of rer stationarity is also analyzed

exchange rate behavior with currency inconvertibility abstract the paper analyzes exchange rate dynamics in a world where the domestic currency is inconvertible into foreign currency and there is a black market for foreign exchange the official exchnage rate is thus set by policy but the black market rate is determined by portfolio balance the stock of domestic money changes with the reported current account and the stock of foreign assets of the private sector changes with smuggling and other unreported current account transactions the effects of capital and current account disturbances as well as the effects of changes in the level and the rate of crawl of the official rate on the black market premium and on the currency substitution ratio are analyzed in variants of the basic model

an admissible monetary aggregate for the united kingdom this paper evaluates the performance of a monetary aggregate that is constructed from principles of economic and index number theory results from tests for weak separability indicate that wholesale deposits should not be aggregated with other u k financial assets they currently are included however in broad monetary aggregates published by the bank of england financial asset groupings passing the weak separability tests then were aggregated using both simple sum and divisia weights in each case the divisia aggregates were more closely related to the growth of nominal gdp and had stable demand for money functions copyright 1991 by mit press

leveraging lotteries for school value added testing and estimation conventional value added models vams compare average test scores across schools after regression adjusting for students demographic characteristics and previous scores this article tests for vam bias using a procedure that asks whether vam estimates accurately predict the achievement consequences of random assignment to specific schools test results from admissions lotteries in boston suggest conventional vam estimates are biased a finding that motivates the development of a hierarchical model describing the joint distribution of school value added bias and lottery compliance we use this model to assess the substantive importance of bias in conventional vam estimates and to construct hybrid value added estimates that optimally combine ordinary least squares and lottery based estimates of vam parameters the hybrid estimation strategy provides a general recipe for combining nonexperimental and quasi experimental estimates while still biased hybrid school value added estimates have lower mean squared error than conventional vam estimates simulations calibrated to the boston data show that bias notwithstanding policy decisions based on conventional vams that control for lagged achievement are likely to generate substantial achievement gains hybrid estimates that incorporate lotteries yield further gains

a semi nonparametric approach to the demand for uk monetary assets we estimate an asymptotically ideal model of the demand for uk personal sector monetary assets we use data that are consistent with utility maximizing behaviour and find that uk monetary assets are generally substitutes in use the estimated elasticities of substitution during the 1980s and the early 1990s indicate that a relatively broad monetary aggregate should be used in economic studies the results also suggest that any policy based on interest or user cost elasticities of substitution between financial assets should be based on the morishima elasticities as the allen uzawa calculation can give misleading results

monetary integration and currency substitution in the ems the case for a european monetary aggregate abstract this paper examines the phenomenon of cross currency substitution and the validity of monetary aggregation within the european monetary system using non parametric methods which exploit the relationship between intergroup substitution and separability the separability property is tested using the methodology developed by varian the nonparametric approach to demand analysis econometrica 50 945 974 1982 nonparametric tests of consumer behaviour review of economic studies 51 99 110 1983 and is violated in the case of most european countries suggesting that the hypothesis of zero currency substitution which forms the basis of national monetary aggregation should be rejected the results do however validate the use of monetary aggregates for the ems as a whole and i use a standard parametric demand for money approach to compare the performance of an ems divisia index with that of simple sum aggregates during the 1980s and 1990s

modeling the ecu against the u s dollar a structural monetary interpretation the proposal that a reformed international monetary system be designed around currency blocs has gained some popularity of late in europe the formation of the euro formalizes the existence of a dm based currency block little academic research has been conducted however on the properties of composite currencies such as the euro in this article we examine the properties of the precursor to the euro namely the ecu against the u s dollar using a monetary framework the article has several novel features our modeling strategy involves starting with underlying equilibrium conditions rather than a final reduced form uses divisia money rather than the more conventional simple sum money interprets in an economic sense the long run relationships and produces an appealing forecasting performance

dynamic stability in a model of dual exchange rates abstract the dynamic stability of a small open economy operating under a regime of dual exchange rates is shown to depend on residents net foreign asset position this result is in contrast to the economy s dynamic behavior under unified fixed rate and flexible rate regimes where stability is unrelated to net foreign asset position

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

portfolio redistribution impacts within the narrow monetary aggregate a number of important monetary and financial changes occurred in the 1980s a rising question among monetary economists is whether the character of m1 has changed substantially as a result in particular a frequent contention is that interest bearing checkable deposits behave as a savings type asset thus subjecting m1 to portfolio redistribution effects in the modern era this research examines the elasticities of substitution for a variety of financial assets pre and post 1980 results indicate that m1 subcomponents do show significant substitution with savings type assets however the portfolio redistribution impacts are not confined to the interest bearing checkable deposits further results indicate that this behavior is not unique to the 1980s copyright 1992 by ohio state university press

semi non parametric estimates of substitution for canadian monetary assets we estimate the dynamic fourier expenditure system to obtain consistent estimates of short run and long run morishima elasticities of substitution for canadian liquid assets we argue that the variability of the estimated elasticities and evidence of less than perfect substitution between monetary assets interferes with the successful use of simple sum aggre gates and traditional log linear money demand functions

exchange rate differential and balance of payments under dual exchange markets abstract this paper develops a model of an economy that uses two exchange markets an official market in which the exchange rate is determined by central bank intervention and a free market in which the exchange rate is determined by market forces the official market handles selected imports and exports while the free market handles the remaining imports and exports and capital transactions the model is used to discuss the effects of various policies on the differential between the free and the official exchange rates and on the balance of payments

bounding an economic monetary aggregate under nonhomothetic preferences we construct nonparametric bounds on true quantity indexes for the realistic case of nonhomothetic preferences these bounds do not require assumptions about the form of the underlying aggregator function we construct these bounds using monetary assets that meet necessary conditions for the existence of an aggregate we find that a tornqvist index of these monetary assets falls within the nonparametric bounds on true quantity indexes almost all of the time whereas a simple sum of these monetary assets falls outside these bounds more than one third of the time

using school choice lotteries to test measures of school effectiveness abstract value added models vams are increasingly used to measure school effectiveness yet random variation in school attendance is necessary to test the validity of vams and to guide the selection of models for measuring causal effects of schools in this paper i use random assignment from a public school choice lottery to test the predictive power of vam specifications in vams with minimal controls and two or more years of prior data i fail to reject the hypothesis that school effects are unbiased overall many commonly used vams are accurate predictors of student achievement gains

tests of different monetary aggregates for the monetary models of the exchange rate in five asean countries this study examines the usefulness of divisia money relative to simple sum money for exchange rate modelling in a period of rapid financial deregulation this comparison is conducted using the monetary model of the exchange rate in the long run modelling the divisia money is significantly superior to simple sum money in the case of malaysia and the philippines while indifferent for indonesia singapore and thailand

admissible monetary aggregates for the euro area we use the fleissig and whitney fleissig a r whitney g a 2003 a new pc based test for varian s weak separability conditions journal of business and economics statistics 21 1 133 144 weak separability test to determine admissible levels of monetary aggregation for the euro area we find that the euro area monetary assets in m2 and m3 are weakly separable and construct admissible divisia monetary aggregates for these assets we show that real growth of the admissible divisia aggregates enters the euro area is curve positively and significantly for the period from 1980 to 2005 out of sample we show that divisia m2 and m3 appear to contain useful information for forecasting euro area inflation

adjustment to monetary policy and devaluation under two tier and fixed exchange rate regimes abstract the purpose of this paper is to determine whether a two tier exchange rate regime is more effective than a fixed rate regime in increasing a country s ability to pursue an independent monetary policy the analysis compares adjustment to a monetary policy and to a devaluation in the two exchange rate regimes in a portfolio model under imperfect assets substitutability it is shown that a two tier exchange rate regime is capable of reducing the current account effects of monetary injection or devaluation only in the long run in the short run however we can get a larger current account response under a two tier regime these results reflect the trade off between quantity and price adjustment

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

monetary policy under dual exchange rates abstract this paper finds that the introduction of dual exchange rates gives the monetary authority greater independence from external constraints than it would otherwise enjoy the monetary authority is able to influence the level of aggregate demand in the short run and to sterilize the effects of temporary foreign disturbances in addition the paper finds that dual rates insulate the domestic economy fully from foreign interest rate changes but do not provide insulation from speculative disturbances

the black market for dollars in brazil the model of the black market for dollars focuses on the interaction of portfolio decisions relevant to the holding of asset stocks and the determinants of net flows of dollars associated with tourism and smuggling a partial equilibrium model of the black market shows that the level of the premium is determined by the official real exchange rate and the official depreciation adjusted interest differential as well as seasonal factors associated with tourism expectations of future exchange rate changes under rational expectations are shown to affect the current level of the black market premium the empirical evidence provides ample support for the role of the key determinants of the premium as well as for an important seasonal pattern the magnitude of the seasonal variation is evidence of the imperfect substitutability between black dollars and cruzeiro assets in portfolios

competitive interest payments on bank deposits and the long run demand for money reply this paper tests two assumptions made in previous demand for money studies the first assumption concerns the role assigned to the interest rate in the demand for money function common practice identifies the rate of interest with the opportunity cost of holding money in section i this formulation is shown to blur an important distinction between the price of money and the price of money substitutes and to implicitly assume that the relevant price variable is the difference between these two distinct prices a second assumption is that the current ban on interest payments on demand deposits is fully effective in section ii i operationally define these price variables and estimate perfectly competitive interest payments on commercial bank deposits this is done by crudely measuring commercial bank marginal costs and assuming that all excess profit is passed on to depositors in indirect ways section iii presents estimates of a more complete longrun demand for money relationship which explicitly includes an own price and a cross price as separate influences and assumes that the prohibition of the payment of interest on deposits is totally ineffective although no firm conclusion is reached concerning the proper functional specification of the demand function the results significantly improve upon previous demand for money estimates which assumed that the interest payment prohibition is totally effective in section iv the results are summarized and implications of the analysis for monetary theory are presented my competitive demand for money formulation leads to a reinterpretation of the existing evidence on what is generally referred to as the interest elasticity of demand for money this estimate is shown to be significantly biased downward it also implies that the demand for and supply of money are more interdependent than is usually assumed

whither armington trade models the armington trade model distinguishes commodities by country of origin and import demand is determined in a separable two step procedure this framework has been applied to numerous international agricultural markets with the objective of modeling import demand in addition computable general equilibrium cge models commonly employ the armington formulation in the trade linkage equations the purpose of this paper is to test the armington assumptions of homotheticity and separability with data from the international cotton and wheat markets both parametric and nonparametric tests were performed and the empirical results reject the armington assumptions this has important implications for international trade modeling and cge modeling

the translog utility function and the demand for money in the united states in recent years considerable effort has been directed towards establishing the nature of the relationship between money and nearmonies but with mixed success the approaches vary from multi interest rate single equation studies to the careful simultaneous equations studies summarized and amended by feige and pearce 1977 and extended recently by donovan 1978 offenbacher 1979 and barnett 1980 the empirical results also vary with numerous studies favoring only one interest rate see the surveys in fisher 1978 1983 some claiming that a variety of entities are close substitutes for money e g chetty 1969 and others showing that weak substitution or even complementarity may be the result of the measurement of elasticities of substitution between money and a number of other assets e g feige and pearce 1977 offenbacher 1979 and barnett 1980 the debate seems to have overshadowed a second and equally intriguing issue which centers on the establishment of an acceptable definition of money the basic idea of this study is to take an approach that takes account of the different degrees of moneyness possessed by the various monetary assets this paper produces quantitative estimates of the degree of substitutability of other monetary assets for money in the context of a flexible functional form model with a

one divisia money for europe in 1992 the eu monetary authorities adopted a harmonized broad money aggregate the emi was subsequently established to promote monetary policy coordination this paper considers how broad money aggregates might be used to guide eu monetary policy and whether a euro divisia monetary index might provide a better guide than a euro simple sum aggregate our findings are based on data from the uk france and germany they indicate that euromoney granger causes europrices and that the eurodivisia monetary index is a better leading indicator of euroinflation than the euro simple sum monetary aggregate

insulation properties of a two tier exchange market in a portfolio balance model when countries peg their currencies to those of their major trading partners they expose themselves to interest sensitive and speculative capital flows that can undermine their ability both to maintain their exchange rate and to pursue an independent monetary policy some countries notably france italy and the belgo luxembourg economic union bleu experimented with two tier exchange rates in the early 1970s in the hopes of insulating their economies from the effects of international capital flows while at the same time protecting foreign trade from exchange rate fluctuations france and italy soon abandoned the experiment but the bleu continues to maintain separate exchange markets with separate exchange rates for current and capital account transactions the commercial exchange rate which relates to the market for current account transactions is generally pegged by the authorities the financial exchange rate determined in the market for capital account transactions is usually free to fluctuate 1 this paper investigates how well a two tier exchange market insulates a small open economy from foreign disturbances taking into account recent developments in the theory of exchange rate determination work by branson 1977 dornbusch 1976 and kouri 1976 suggests that the short run equilibrium value of the exchange rate is determined along with interest rates by demand and supply in the markets for financial assets this asset market or portfolio balance approach to exchange rate determination is particularly well suited to a study of the two tier exchange market one can view the financial exchange rate as a relative asset price it is among the variables that equilibrate asset markets and it is determined in the short run in those asset markets previous theoretical work on the two tier exchange market has generally been within the mundellian framework the financial exchange rate has been treated as equating a flow demand and supply of foreign exchange the asset market approach has the advantage of carefully distinguishing between stocks and flows in particular it treats demands for assets as stock demands that are realized instantaneously so that actual holdings of assets always reflect the desired composition of the portfolio disturbances to portfolio equilibrium create immediate stock adjustments as portfolios are rebalanced causing instantaneous changes in endogenous market clearing variables in addition disturbances alter the rate of accumulation the flow of financial assets over time portfolio balance models of two tier exchange rates can be found in dornbusch 1976 and decaluwe and steinherr 1976 but they differ from the one presented here dornbusch partitioned the exchange market so that interest income a current account transaction was channelled through the financial market that segmentation yields a different expected rate of return on foreign

consumer theory and the demand for money the following sections are included introductionthe definition of moneythe microeconomic theory of a monetary economythe aggregation theoretic approach to money demandindex number theorythe links between aggregation theory index number theory and monetary theoryunderstanding the new divisia aggregatesthe optimal level of monetary subaggregationeconometric considerationsapproximating the monetary services subutility functionan exampleempirical dimensionsempirical comparisons of index numbersempirical results for the demand system approachextensionsconclusions this abstract was borrowed from another version of this item

the composition and construction of monetary aggregates an economic monetary aggregate is composed from a set of monetary goods that are at least weakly separable from other goods in the optimizing agent s utility function we construct such an aggregate using a divisia index number we demonstrate that through the middle of the 1980s forecasts of the inflation rate based on our economic monetary aggregate are superior to forecasts based on the simple sum monetary aggregates m1 or m2

sweep programs and optimal monetary aggregation abstract this paper examines the admissibility of monetary aggregate groupings for the us over 1993 2001 based upon weak separability we investigate the impact of retail and commercial demand deposit sweep programs on the separability of monetary asset groupings weak separability is tested using the swofford whitney and fleissig whitney tests we use varian s measurement error adjustment procedure to eliminate violations of the generalized axiom of revealed preference garp when funds from both retail and commercial demand deposit sweep programs are placed within checkable deposits all groupings narrow and broad pass garp and weak separability for groupings based on conventional money measures tests tend to favor broad aggregates

relative prices in the uk personal sector money demand function nonparametric demand analysis is used in order to establish admissible monetary aggregates and also to establish a potential role for relative prices in the money demand function a conventional money demand specification is then contrasted with a money demand function which contains the relative prices of durables nondurables and services as additional regressors evidence from long run cointegration analysis short run error correction models and nonnested testing all confirm a role for relative prices in the u k personal sector s money demand function copyright 1996 by royal economic society

a new empirically weighted monetary aggregate for the united states i introduction this article uses an approach to long run econometric modeling proposed by pesaran et al 2001 hereafter pss to develop an empirically weighted broad monetary aggregate for the united states and to demonstrate the advantages of this type of aggregate from a monetary policy perspective in particular we examine the ability of this type of approach to deal with periods of significant financial innovation and money demand instability a key requirement for monetary aggregates to provide a useful role in guiding monetary policy is that they should be stably related to the objectives of policy such as inflation or nominal income growth in this context the united states has exhibited periodic evidence of significant money demand instability most notably these have been goldfeld s 1976 case of the missing m1 in 1973 74 and the missing m2 episode of the early 1990s feldstein and stock 1996 in both cases the aggregate in question experienced a significant velocity increase and as a consequence previously established and apparently stable money demand relationships began to seriously overpredict the growth in these aggregates the missing m1 episode in 1973 74 together with subsequent evidence that m2 was more predictable than m1 led many economists to use m2 as an indicator of nominal activity hence during the 1980s m2 became the primary intermediate target of monetary policy furthermore the primacy of m2 appeared to be well supported by the available empirical evidence feldstein and stock 1994 for example established that the rate of change of m2 was a statistically significant predictor of the rate of change of nominal gross domestic product gdp over the period 1959 92 furthermore m2 remained statistically significant when short term interest rates were added to the relationship subsequent research such as miyao 1996 and estrella and mishkin 1997 however cast doubt on the robustness of this result carlson et al 2000 p 34 for example summarize the current situation by arguing that the promising empirical conclusions of feldstein and stock 1994 that established predictive content for m2 in a vector error correction setting do not seem to find support in data that extend through the mid 1990s the key factor behind the breakdown in the m2 relation appears to have been the substitution away from time deposits and into mutual funds particularly stock and bond mutual funds in the low interest rate environment of the early 1990s although the definition of m2 has been expanded by the federal reserve in the past to include money market mutual funds mmmfs and money market deposit accounts mmdas for example a number of analysts duca 1995 darin and hetzel 1994 orphanides et al 1994 have advocated that m2 should be expanded further to include these stock and bond mutual funds m2 significantly these studies typically use the simple sum aggregation approach in which all component assets are given equal and constant weights over time this approach does not seem consistent however with the accumulating evidence of a significant shift in wealth holders preferences sometime in the early 1990s carlson et al 2000 for example add to the empirical evidence that had accumulated during the 1990s by suggesting that the instability was associated with a permanent upward shift in m2 velocity between 1990 and 1994 furthermore they argue that our results support the hypothesis that households permanently reallocated a portion of their wealth from time deposits to mutual funds p 381 clearly simple sum aggregation is not able to take account of these changes in preferences more significantly however simple sum aggregation cannot take account of any changes in the relationship between component assets and nominal income over time although carlson et al 2000 do manage to reestablish a stable money demand relationship for the mzm money at zero maturity and m2m m2 minus small time deposits aggregates through the 1990s this is only possible by specifically accounting for the financial innovation that occurred in the early 1990s