the tail index of exchange rate returns in the literature on the empirical distribution of foreign exchange rates there is now consensus that exchange rate yields are fat tailed three problems however persist 1 which class of distribution functions is most appropriate 2 are the parameters of the distribution invariant over subperiods 3 what are the effects of aggregation over time on the distribution in this paper we employ extreme value theory to shed new light on these questions we apply the theoretical results to ems data

intertemporal pricing and price discrimination a semiparametric hedonic analysis of the personal computer market we apply a smooth coefficient semiparametric model to a unique high frequency data set to examine the intertemporal pricing of personal computers furthermore we test whether firms charge differential component prices for their top performance personal computers and whether premium firms charge both a premium for all their computers and a premium for their top performance ones we find nonlinear effects in the pricing of personal computer components we also find that firms in general do not charge differential prices for the components of their top performance computers in addition high quality firms charge higher premia only for their most advanced products copyright 2006 john wiley sons ltd

demand elasticities for food products in brazil a two stage budgeting system the object of this article is to estimate demand elasticities for a basket of staple food important for providing the caloric needs of brazilian households these elasticities are useful in the measurement of the impact of structural reforms on poverty a two stage demand system was constructed based on data from household expenditure surveys pof produced by ibge the brazilian bureau of statistics in 1987 88 and 1995 96 we have used panel data to estimate the model and have calculated income own price and cross price elasticities for eight groups of goods and services and in the second stage for 11 sub groups of staple food products we estimated those elasticities for the whole sample of consumers and for two income groups

u s bilateral trade flows and exchange risk during the floating period abstract this paper tests for real exchange rate risk effects on u s bilateral trade flows during the floating period using several new as well as previously used risk measures significant negative effects occur in five of six u s import flows and in two of six u s export flows with one export flow showing a significant positive effect these results are consistent with several previous findings for aggregate u s trade two risk measures using the forward exchange rate and assuming a time varying risk premium provide marginally more significant results than the others

semiparametric estimation and consumer demand this paper considers the implementation of semiparametric methods in the empirical analysis of consumer demand the application is to the estimation of the engel curve relationship and uses the british family expenditure survey household composition is modelled using an extended partially linear framework this is shown to provide a useful method for pooling non parametric engel curves across households of different demographic composition c 1998 john wiley sons ltd

preference heterogeneity and the rank of demand systems this article examines the effect of preference heterogeneity on nonparametric and parametric tests of the rank of demand systems using samples of households drawn from the u k family expenditure survey we find that preference heterogeneity increases the rank of demand systems when the effects of household characteristics on demand are removed by semiparametric techniques a rank 3 demand system appears to be an adequate empirical specification for all samples

some models for estimating technical and scale inefficiencies in data envelopment analysis in management contexts mathematical programming is usually used to evaluate a collection of possible alternative courses of action en route to selecting one which is best in this capacity mathematical programming serves as a planning aid to management data envelopment analysis reverses this role and employs mathematical programming to obtain ex post facto evaluations of the relative efficiency of management accomplishments however they may have been planned or executed mathematical programming is thereby extended for use as a tool for control and evaluation of past accomplishments as well as a tool to aid in planning future activities the ccr ratio form introduced by charnes cooper and rhodes as part of their data envelopment analysis approach comprehends both technical and scale inefficiencies via the optimal value of the ratio form as obtained directly from the data without requiring a priori specification of weights and or explicit delineation of assumed functional forms of relations between inputs and outputs a separation into technical and scale efficiencies is accomplished by the methods developed in this paper without altering the latter conditions for use of dea directly on observational data technical inefficiencies are identified with failures to achieve best possible output levels and or usage of excessive amounts of inputs methods for identifying and correcting the magnitudes of these inefficiencies as supplied in prior work are illustrated in the present paper a new separate variable is introduced which makes it possible to determine whether operations were conducted in regions of increasing constant or decreasing returns to scale in multiple input and multiple output situations the results are discussed and related not only to classical single output economics but also to more modern versions of economics which are identified with contestable market theories

the structure of technical efficiency it is common practice to decompose measures of efficiency into component measures of technical and allocative efficiency in this paper we show how and why to decompose a general measure of technical efficiency into component measures of purely technical efficiency congestion and scale efficiency and we investigate the properties of each measure we do so for a multiple output technology which satisfies a weak axiom system that does not include either constant returns to scale or strong input disposability

the statistical properties of daily foreign exchange rates 1974 1983 abstract this paper examines the statistical properties of daily rates of change of five foreign currencies from 1974 to 1983 the main purpose is to discriminate between two competing explanations for the observed heavy tails of the distribution that the data are independently drawn from a heavy tail distribution which remains fixed over time and that the data come from distributions which vary over time evidence point to the rejection of the first hypothesis further investigations show that the rejection can be attributed to changing means and variances in the data which can be described by a simple statistical model

upward bias in the consumer price index under the zero inflation economy abstract this study estimates the demand system using japanese microdata and calculates the cost of living index coli in the recent zero inflation situation the consumer price index cpi can approximate the coli while there are upward biases in the cpi during the 1980s

the statistical distribution of exchange rates empirical evidence and economic implications the abundant evidence that changes in exchange rates have distributions with fatter tails than the normal distribution has led researchers to consider non normal distributions including the student the stable paretian and mixtures of distributions this paper compares the empirical fits of three non normal candidates and the normal distribution for daily changes in the logarithms of exchange rates using maximum likelihood estimation of the parameters and chi square goodness of fit tests the student and mixture of two normals provide the best fits but there is evidence that the distribution parameters may vary over time

a life cycle consistent empirical model of family labour supply using cross section data this paper estimates a utility maximising model of the joint determination of male and female labour supplies using a sample of married couples from the u k family expenditure survey the emphasis is on the estimation of within period preferences that are consistent with intertemporal two stage budgeting under uncertainty however the approach we adopt provides an alternative method of estimating certain aspects of life cycle behaviour to the fixed effects constant approach of heckman and macurdy 1980 macurdy 1981 and browning deaton and irish 1985 moreover it relaxes some of the underlying restrictions that are implicit in these constant models under uncertainty

the engel curve for alcohol and the rank of demand systems this paper shows that the quadratic shape of the engel curve for alcohol is induced by preference heterogeneity between drinkers and abstainers in a japanese data set with controlling the heterogeneity it is shown that the engel curve for alcohol slopes monotonically downwards for drinkers and that the probability of being a drinker is an increasing function of total expenditure these two relationships generate a quadratic shape for the engel curve for alcohol other goods in this data set appear to have nearly linear engel curves so if the alcohol engel curve for drinkers is also linear then after controlling for this preference heterogeneity the rank of this demand system would be two copyright 2006 john wiley sons ltd

equivalence scales in a rank 3 demand system abstract in the context of a rank 3 demand system equivalence scales measuring the cost of demographic characteristics independently of the base utility level can be identified from cross section data without demographic separability restrictions although this can also be achieved with a rank 2 demand system that contains a nonlinear log expenditure term in its budget shares tests performed in a nested framework suggest that the rank 3 demand system approach is empirically superior the informative structure of the rank 3 demand system is used to estimate a detailed pattern of demographic costs including the cost of single parenthood and economies of scale within the family

estimates of the black economy based on consumer demand approaches we propose a consumer demand system approach to estimating the size of the black economy where alternative hypotheses affecting the empirical results can be tested in a nested framework this approach allows for the estimation of the under reporting of household income from various sources dispensing with the need to use arbitrary criteria to classify households by their main source of income it also avoids potential bias in black economy estimates arising from mistaking preference heterogeneity substitution as income effects we illustrate these arguments by estimating the extent to which self employment income in the uk is underreported using parametric and nonparametric techniques the black economy broadly defined as the economic activities that are hidden from public authorities to avoid taxation has recently received increased attention in the literature due to arguments that the rising tax burden and state regulation is driving economic activity underground tanzi and schuknecht 1997 enste and schneider 1998 the usefulness of attempts to estimate the size of the black economy however is a controversial issue the sceptics emphasise the difficulties associated with the precise definition of black economy activities and point to the widely different estimates of the size of these activities resulting from alternative methods dixon 1999 tanzi 1999 thomas 1999 authors approaching the subject in an optimistic frame of mind emphasise positive aspects of estimating the size of the black economy such as the correct measurement of gdp and other macroeconomic variables e g employment and the design of policy and econometric models bhattacharyya 1999 giles 1999 the controversy on estimation issues however does not subtract from the widespread concern about the undesired consequences of the black economy undeclared economic activities reduce the tax base thereby undermining the financing of public goods and social protection a country trying to curtail the loss of tax revenue by raising tax rates can create a vicious cycle as this reinforces the incentive not to declare economic activities to the public authorities high tax rates have a distorting effect resulting in inefficient allocation of resources due to unequal opportunities and willingness to evade in different sectors of the economy and can undermine the ability of the country to compete internationally distortions in the labour market can also arise because individuals working in the black economy may have difficulty in moving from one job to another furthermore in countries where health pension and other social security payments are not universal individuals working in the black economy and their families are outside the

welfare comparison under exact aggregation new econometric model of aggregate consumer behavior in the united states and to apply this model to the analysis of impacts of alternative economic policies on the welfare of individual consuming units the model incorporates time series data on quantities consumed prices the level and distribution of income and demographic characteristics of the population it also incorporates cross section data on the allocation of consumer expenditures for households with different demographic characteristics our econometric model is based on the theory of exact aggregation developed by lau 1977a c this theory makes it possible to dispense with the notion of a representative consumer in constructing models of aggregate consumer behavior one of the most remarkable implications of lau s theory of exact aggregation is that systems of demand functions for individuals with common demographic characteristics can be recovered uniquely from the system of aggregate demand functions using the individual demand functions we can analyze the impact of economic policy on consumer welfare

simple tests of distributional effects on macroeconomic equations the presence of distributional effects in macroeconomic equations is shown to coincide with nonlinearity in micro behavioral relationships parameters estimated with aggregate data as in representative agent models contain distributional biases that are not measurable using aggregate data alone tests for distributional effects and other measures of the extent of aggregation problems are derived using distributional data observed over time significant distributional effects are noted for a model of annual aggregate u s commodity expenditure data a static model that accommodates individual heterogeneity is found to be statistically equivalent to a simply dynamic model that accommodates first order autocorrelation

nesting quadratic logarithmic demand systems abstract we propose a new generalised rank 3 demand system which nests all known and new rank 3 and rank 2 demand systems derived from the quadratic logarithmic ql cost function we investigate its statistical adequacy against commonly encountered alternatives using uk household data

on estimating the cost of characteristics indices from consumer demand analysis we examine the information content of relative equivalence scales using a multiperiod framework and argue that in the absence of independence of base ib these scales can be uniquely identified from demand analysis only when the transformations of preferences through time are the same for all household types a property termed as intertemporally invariant base iib utility restrictions imposed by iib on conditional demands are tested empirically and found rejected within the context of a rank 3 demand system applied to individual household data drawn from the u k family expenditure survey 1970 86 welfare implications of false iib assumptions are also empirically investigated jel classification d1 a propos de l estimation du cout des indices caracteristiques a partir de l analyse de la demande des consommateur ce memoire examine le contenu informationnel des echelles d equivalence relative en utilisant un cadre d analyse sur plusieurs periodes et suggere que en l absence d une independance de la base ib ces echelles peuvent etre identifiees d une maniere univoque seulement si les transformations de preferences dans le temps sont les memes pour tous les types de menages on nomme cette propriete utilite de base invariante dans le temps iib les restrictions verifiables imposees par iib sur les demandes conditionnelles sont verifiees empiriquement et sont rejetees dans le contexte d un systeme de demande de rang 3 applique aux donnees des menages individuels dans une etude des depenses des menages de la grande bretagne 1970 86 les implications de faux postulats iib sont analysees empiriquement

measuring productivity growth under factor non substitution an application to us steam electric power generation utilities a theoretical framework is developed for decomposing partial factor productivity and measuring technical inefficiency when the underlying technology is characterized by factor non substitution with farrell s 1957 radial index of technical inefficiency being inappropriate in this case russell non radial indices are adapted to measure technical inefficiency in a leontief type model a system of factor demand equations with a regime specific technical inefficiency term is proposed and estimated allowing for dependence across inputs using a copula approach then the paper presents a complete decomposition of partial factor productivity changes using a dataset of us steam power electric generation utilities

the effects of male and female labor supply on commodity demands we examine the effects of male and female labor supply on household demands and present a simple and robust test for the separability of commodity demands from labor supply using data on individual households from six years of the uk fes we estimate a demand system for seven goods which includes hours and participation dummies as conditioning variables allowance is made for the possible endogeneity of these conditioning labor supply variables we find that separability is rejected furthermore we present evidence that ignoring the effects of labor supply leads to bias in the parameter estimates

bilateral trade flows the linder hypothesis and exchange risk bilateral trade flows are used to examine the linder hypothesis and the effect of exchange rate variability in a gra vity type trade model derived from an underlying demand and supply mo del a behavioral model is used to justify examining these issues joi ntly the model performs well empirically using a sample of seventeen countries for the period 1974 82 the authors find overwhelming supp ort for the linder hypothesis and this version of the gravity model moreover they find strong support for the hypothesis that increased exchange rate variability affects bilateral trade flows copyright 1987 by mit press

a rational rank four demand system past parametric tests of demand system rank employed polynomial engel curve systems however by gorman s 1981 theorem the maximum possible rank of a utility derived polynomial demand system is three the present paper proposes a class of demand systems that are utility derived are close to polynomial and have rank four these systems nest rational polynomial demands and so can be used to test ranks up to four these systems are suitable for applications where high rank is likely such as demand systems involving a large number of goods a test of rank using this new class of systems is applied to uk consumer demand data

semi radial technical efficiency measurement semi radial efficiency measurement combines technical efficiency as captured by the classical farrell measure with an economically meaningful mix efficiency component the semi radial evaluation we propose proceeds in two steps first we build on the price interpretation of the generally accepted koopmans efficiency notion to characterize appropriate benchmarks next we present both a quantity based distance measure and its dual price based equivalent to evaluate the mix efficiency factor the type of measures we propose may e g be used to provide a price rationale for the zieschang technical efficiency evaluation procedure

product mixes as objects of choice in non parametric efficiency measurement abstract non radial measures of technical efficiency essentially differ from their radial counterparts in that the product mix of the efficient reference is allowed to be different from the product mix of the evaluated observation whereas existing non radial measures are still based on the product mix of the evaluated i e possibly inefficient observation we change the perspective and propose a measure based on the mix properties of the efficient reference the resulting inverse measure can be considered as complementary to the fare lovell or russell efficiency measure

estimates of semiparametric equivalence scales within the semiparametric framework introduced by pendakur 1999 we introduce a new loss function to estimate equivalence scales this loss function uses all available information from the total expenditures of both the reference and nonreference households and as such it produces more reliable estimates using canadian family expenditure data for 1996 we apply this loss function to obtain equivalence scale estimates for a variety of expenditure share categories such as food fuel and clothing copyright 2006 john wiley sons ltd

testing the rank of engel curves with endogenous expenditure abstract we find that the endogeneity of consumer expenditure tends to increase the estimated rank of engel curves this result based on nonparametric procedure is in line with previous results obtained in the context of parametric specifications

measures of technical efficiency abstract fare and lovell j econom theory 19 1978 150 162 suggest four properties that a measure of technical efficiency should satisfy the commonly employed debreu farrell measure fails three of them necessary and sufficient conditions for a measure to satisfy the four conditions are provided and recently proposed measures are analyzed in the light of this result also it is argued that the debreu farrell measure has several desirable properties when one takes account of 1 perhaps unknown market prices and the relationship between technical and economic efficiency and 2 its characterization as a measure of economic efficiency using the shadow prices implicit in the production technology

what do we learn about consumer demand patterns from micro data the aim of this paper is to assess the importance of using micro level data in the econometric analysis of consumer demand to do this we utilize a time series of repeated cross sections covering some 4 000 households in each of 15 years employing a number of different aggregation procedures we conclude that aggregate data alone are unlikely to produce reliable estimates of structural price and income coefficients however once certain aggregation factors as well as trend and seasonal components are included an aggregate model is not necessarily outperformed across all demand equations in terms of forecasting ability jel d12 c52 c31 the purpose of this paper is to develop a complete consumer demand system based on a time series of individual household data and to use it to measure the biases introduced into the study of consumer de mand behavior when aggregate data are used in place of the appropriate microeco nomic data we assess the suitability of ag gregate data through the impact on income and price elasticities and by evaluating the ability of both micro and aggregate based models to forecast aggregate consumer de mand the biases introduced by the use of aggregate data depend upon the way that household characteristics interact with in come and price effects and on departures of demand systems from linearity we explore the structure of microeconomic demand sys tems and the role of household characteris tics in the behavior of consumer demand both for the light this may shed on the pattern of future demands and for the im plications this behavior has for issues of aggregation consumer demand patterns typically found in micro data sets vary considerably across households with different household characteristics and with different levels of income we model this variability by making intercept and slope parameters in the budget share equations of our demand sys tem depend on household characteristics and by allowing for nonlinear total log expenditure terms in fact in theory consistent demand systems it is total ex penditure rather than disposable income that is allocated across goods we find that this general framework leads to a well specified data coherent demand system which is a quadratic extension of the popu lar almost ideal model of angus s deaton and john muellbauer 1980 the micro level estimates are shown to be sensitive to the treatment of endogeneity of total expen diture and to the specification of interaction terms with household characteristics in ad dition this specification is also shown to possess many attractive features for the evaluation of aggregate models

estimation of complete demand systems from household budget data the linear and quadratic expenditure systems in this paper we explore two issues in empirical demand analysis the estimation of complete systems of demand equations using household budget data section i and the incorporation of demographic characteristics into such systems section ii although there are numerous studies which use time series data to estimate complete demand systems and many which estimate engel curves from household budget data there are virtually none which combine budget data from different periods to estimate complete systems since each budget study corresponds to a single price situation one might conjecture that estimation of complete systems would not be possible unless budget studies were available from a large number of periods this is incorrect in section i we argue that interesting complete demand systems can be estimated from a small number of budget studies despite the limited price variability represented in such data to demonstrate this we use budget study data for two periods to estimate a pair of related demand systems the familiar linear expenditure system les and a quadratic expenditure system qes a generalization of les in which the demand equations are quadratic in total expenditure the inclusion of demographic variables in the analysis of household consumption patterns is desirable because there are likely to be systematic differences in the consumption behavior of households with different demographic characteristics but the effects of demographic characteristics have seldom been studied within the framework of complete demand systems in section ii we propose translating as a general method for incorporating demographic variables into complete systems of demand equations this method has not previously been discussed as a general technique for bringing demographic variables into demand systems although it has been employed in several studies to improve the estimates of the les and the qes presented in section i we reestimate these two systems using translating to incorporate family size

quadratic engel curves and consumer demand this paper presents a model of consumer demand that is consistent with the observed expenditure patterns of individual consumers in a long time series of expenditure surveys and is also able to provide a detailed welfare analysis of shifts in relative prices a nonparametric analysis of consumer expenditure patterns suggests that engel curves require quadratic terms in the logarithm of expenditure while popular models of demand such as the translog or the almost ideal demand systems do allow flexible price responses within a theoretically coherent structure they have expenditure share engel curves that are linear in the logarithm of total expenditure we derive the complete class of integrable quadratic logarithmic expenditure share systems a specification from this class is estimated on a large pooled data set of u k households models that fail to account for engel curvature are found ro generate important distortions in the patterns of welfare losses associated with a tax increase

robust non parametric measures of exchange rate variability changes in exchange rates are well known to possess non gaussian distributions yet in testing for differences in exchange rate volatility few researches have examined measures that do not assume gaussian data this paper develops a robust non parametric measure for comparing exchange rate variability across time the measures are applied to monthly exchange rate data to test for differences in exchange rate variability across different monetary policy regimes the comparison show inconsistencies between conclusions based on the classical f test and the robust non parametric equivalent using the robust test for changes in exchange rate variability we do not conclude that variability has increased over time increases in variability do occur but usually only in specific percentiles of the data