Gaids: a generalised version of the almost ideal demand system

AIDS is a popular model in empirical demand literature. In this paper a generalised version of AIDS (GAIDS) is presented, estimated and statistically tested. Evidence from Italian household data suggests rejection of AIDS, also when demographic effects are considered.     

Invariance, price indices and estimation in almost ideal demand systems

Two issues are addressed in this paper. First, we explore the issue of price index invariance in the linearized Almost Ideal demand system. We establish that the Stone index, which lacks invariance, and the recently proposed invariant Laspeyres, Paasche and Tornqvist indices all generate biased and inconsistent estimators. Monte Carlo evidence shows that invariance does not necessarily lead to better estimates of price and income elasticities insofar as the Stone and Paasche indices are unambiguously inferior to the Laspeyres and Tornqvist indices, especially if prices are not strongly positively correlated. Second, we examine the merits of the widely used conditional ML estimator of the non-linear Almost Ideal system in which a prior value is chosen for the “subsistence” parameter. We find that the bias and trace mean square error increases induced by conditional estimation are modest. The choice between the linearized and the non-linear models favors the latter although in some cases linear methods are as good as non-linear. First Version Received: January 1999 / Final Version Received: March 2000     

Dynamic almost ideal demand systems: an empirical analysis of alcohol expenditure in Ireland

This paper presents a dynamic form of the Almost Ideal Demand System (AIDS). Three versions of the static AIDS model are employed to determine the preferred long-run equilibrium model and represents the short-run dynamics by an error correction mechanism. This estimation procedure is then applied to alcohol expenditure in Ireland. The estimated point elasticities are consistent with previous studies and a priori expectations. Beer and spirits are found to be price inelastic in both the short and long run. While wine is price inelastic in the short run and price elastic in the long run.     

Linear approximations to the quadratic almost ideal demand system

This paper investigates linear approximations to the recently popular quadratic almost ideal demand system (QUAIDS) by proposing a new composite variable and conducting a simulation study. The linear approximations are especially useful when one uses nonstationary time series, to which nonlinear systems are difficult to apply properly. The new composite variable performs well in combination with the price indices appropriate for linearizing the almost ideal demand system. The QUAIDS can be linearly approximated on a practical basis if the appropriate combinations of composite variables and elasticity formulas are employed and the base point is set to the point of evaluation.

The US retail demand for fish products: an application of the almost ideal demand system

The main objective is to address the limitations of past US fish demand research through the development of a variation of the almost ideal demand system model for disaggregate fish products at the retail level. Price and expenditure elasticities, as well as elasticities of substitution between fish products and other protein commodities, determined from this work may be used in the context of fisheries management and market development and promotion. Results indicate that with the exception of shellfish, demand for the various fish products is relatively inelastic. Cross-price elasticities are generally moderate while expenditure elasticities are large and positive for fresh fish and shellfish. Demographic effects, especially geographical division, season, race, occupation, age–sex household composition, and price–income interaction, as a proxy for quality, are highly significant variables.     

Estimating technology in the postal sector: a Bayesian approach

The aim of this article is to study the technology of the sector represented by the Spanish national post-office and telegraph service, Sociedad Estatal Correos y Telégrafos, S.A. trading as Correos, and denominated as such hereafter. Concretely, we analyse economic efficiency (technical and allocative) and scale economies of the production units (cost centres) of Correos. To do this, we employ a methodology based on an input distance function which is the dual of the cost function. Moreover, and applying duality theory, we develop an economic model to assess the effect of postal infrastructures on the operators’ costs. In order to carry out the empirical model, Bayesian econometrics is applied to estimate the parameters in the input distance function and the technical and allocative efficiency terms.     

Forecasting with the almost ideal demand system: evidence from some alternative dynamic specifications

The almost ideal demand system is used as a representation of long run demands in discrete time and continuous time error correction models to produce forecasts of budget shares beyond the sample period. The estimated models are subjected to a battery of tests, and an analysis of the forecasts indicates that continuous time adjustment mechanisms, based around fully modified estimates of the long run preference parameters, provide a remarkably accurate method of forecasting budget shares.     

An almost ideal demand system for alcoholic beverages in British Columbia

An almost ideal demand system for alcoholic beverages in British Columbia is estimated based on five beverage categories. Estimates of the model unrestricted and restricted to satisfy homogeneity and symmetry are presented. The restrictions are tested: as is common in applied demand analysis a number of rejections are encountered, although within-equation tests tend to support homogeneity. The rejections which are encountered are not mitigated by the inclusion of dynamic elements. The Slutsky matrix is used to examine the concavity of the expenditure function, which is found to be mildly violated. Marshallian and Hicksian own-, cross-price, and income elasticities are calculated and are found to be largely consistent with previous findings, although some noteworthy results are obtained.     

Aggregation effects on price and expenditure elasticities in a quadratic almost ideal demand system

Abstract.  While it is well known that demand elasticities calculated at the macro level will in general differ from those calculated at the micro level because of aggregation effects, there remain the questions of how large the effects are and how they vary with the degree of inequality in the income distribution. We explore these questions with models based on a quadratic version of the Almost Ideal Demand System. We investigate the elasticity differences theoretically and then calibrate the models and generate numerical results, using income data for seven countries with widely different distributions. The aggregation effects are found generally to be rather small, even with highly unequal income distributions.     

A Bayesian approach to aggregation in demand systems: smoothing with perfect substitution priors

Demand analysis requires aggregation of commodities. Some are imposed at the data collection level, leaving some for the estimation level. When data are collected, the implicit assumption underlying the aggregation is perfect substitutability: one gallon of gasoline is viewed by consumers as equivalent to another gallon; hence, the two are added together. While such aggregation can be carried out further by the data analyst, it is difficult to incorporate perfect substitutability into the estimation of direct demand systems. Perfect substitution in that context implies discontinuous demand functions, which are not nested within standard empirical demand systems. Perfect substitution is much more easily handled in a system of inverse demands, though an empirical method to impose perfect substitutability in an inverse demand system has not previously appeared in the literature. In this article, we develop such a method, which allows perfect substitutability to be imposed as a prior restriction. We use Leamer’s information contract curve as a tool to flexibly impose the substitution restriction and to investigate consistency between the data and prior. We illustrate the method with an application to inverse demands for fish in Korea.     

Testing for negativity in a demand system: A Bayesian approach

The paper introduces Bayesian inference into a demand model. This allows us to test for the negativity condition of the substitution matrix which is difficult to handle directly in the traditional approach. To illustrate the Bayesian inference procedures, we estimate the Rotterdam model and test the demand properties using Japanese data. The empirical results show the importance of specifically considering negativity in demand analysis. First version received: September 1997/final version received: February 1998     

An investigation into the demand for alcoholic beverages in Canada: a choice between the almost ideal and the Rotterdam models

In this article I investigate the historical pattern of interactions in the demand for three categories of alcoholic beverages in Canada, using both the differential Almost Ideal and the differential Rotterdam demand systems. I evaluate these models based on several decision criteria including model encompassment (based on the J-test), structural stability, conformity with demand theory and the credibility of the estimated price and income responses, in an attempt to determine which of these models is better suited for explaining the demand for alcoholic beverages. The results reveal that both models satisfy the restrictions of demand theory and of structural stability but the Rotterdam model is preferable on grounds of the remaining two criteria.     

A globally flexible,quadratic almost ideal demand system: an application to demand for meats and fish in Taiwan

A new demand system, called a globally flexible, quadratic almost ideal demand system (GF–QUAIDS), integrates both the quadratic Engel curve and the Fourier series. This novel GF–QUAIDS model is applied to study the demand for meats and fish in Taiwan. Empirical results show that the GF–QUAIDS fits the data well and that, by using the likelihood ratio test, its nested models are rejected, including the locally flexible functional form and the linear Engel curve. Nevertheless, other empirical model-selection measures indicate that the GF–QUAIDS can be as good as its famous nested models such as the AIDS, QUAIDS and GF–AIDS.     

Estimating the elasticities of gasoline demand: an instrumental variable approach

This article uses a new identification strategy to estimate the demand for gasoline. I show that the monthly gasoline price is endogenous to gasoline demand at the state level, and that gasoline tax and domestic oil first purchasing price together are strong and valid instruments to correct for the endogeneity bias. In addition to estimating the price elasticity, this article also provides an estimate of the income elasticity. These updated estimates are critical factors in evaluating the environmental effect of gasoline tax and forecasting gasoline consumption.     

Revisiting the interest rate–exchange rate nexus: a Markov-switching approach

In this paper the interest rate–exchange rate nexus and the effectiveness of an interest rate defense are investigated empirically. I present a reduced form evidence which characterizes the empirical relationship between interest rates and exchange rates. I use a Markov-switching specification of the nominal exchange rate with time-varying transition probabilities. Empirical evidence from six developing countries: Indonesia, South Korea, the Philippines, Thailand, Mexico, and Turkey indicates that raising nominal interest rates leads to a higher probability of switching to a crisis regime. Thus, the empirical results presented here may support the view that a high interest rate policy is unable to defend the exchange rate. Unlike other studies which consider linear models only, my findings are robust and consistent over different countries and crisis episodes (Asian 1997 crises, Mexico 1994 crisis, and Turkey 1994, 2001 crises). In order to explain the empirical findings, I construct a simple theoretical model by incorporating an interest rate rule in the model proposed by Jeanne and Rose (2002) [Jeanne, O., Rose, A.K., 2002. Noise trading and exchange rate regimes, Quarterly Journal of Economics. 117 (2) 537–569]. The model has multiple equilibria, and under plausible conditions, higher exchange rate volatility is associated with higher interest rates.     

On estimation of almost ideal demand system using moving blocks bootstrap and pairs bootstrap methods

This paper applies a bootstrap method to the Almost Ideal Demand System (AIDS) proposed by Deaton and Muellbauer (Am Econ Rev 70:312–326, 1980), where the moving blocks bootstrap (MBB) and pairs bootstrap (PB) methods are adopted taking into account serially correlated error terms and limited dependent variables (note that the dependent variables in the AIDS model lie on the interval between zero and one). We aim to obtain the empirical distribution of the expenditure and price elasticities. Note that, the expenditure and price elasticities are obtained using the parameter estimates included in the AIDS model. In the past, a few studies report both the elasticity estimates and their standard errors obtained from the Delta method, but most of studies show only the elasticity estimates (i.e., statistical tests have not been done in most of the past studies). Applying MBB and PB methods to the AIDS model and using Japanese monthly household expenditure data from January, 1975 to December, 2012, we show in this paper that a few elasticities are statistically insignificant. We also compare the standard errors based on the bootstrap method with those based on the Delta method. We obtain the results that the differences between the Delta method and the bootstrap method are not negligible. In addition, the validity of the linear approximated AIDS (LA–AIDS) model which is commonly used in empirical studies is examined. In consequence, we find that the LA–AIDS model shows a poor performance, compared with the AIDS model, because the LA–AIDS model yields inconsistency on the elasticity estimates.     

Time-varying effects of fiscal policy in Spain: a Markov-switching approach

How have the effects of Spanish fiscal policy varied over time? Given this starting point, in this article we analyse the regime dependence of fiscal policy in Spain by estimating a vector autoregressive model within a Markov-switching framework. Our results indicate that Spain’s membership of the Economic and Monetary Union (EMU) is the most likely source of time variation in the fiscal outcomes. Accordingly, increases in the primary deficit-to-GDP ratio do not succeed in stimulating economic activity in the first regime; rather, unexpected upsurges in the primary deficit harm economic activity (non-Keynesian effect) in the second regime, which prevails since the ratification of the Maastricht Treaty.     

Food expenditures and household demographic composition in the US: a demand systems approach

Food expenditures and subsistence quantities of poverty status and non–poverty status US households are analysed within a Linear Expenditure System that postulates subsistence quantities to be linear combinations of demographic variables. Using the US Bureau of Labor Statistics' 1992 Consumer Expenditure Survey and Detailed Monthly Consumer Price Indices, this article obtains expenditure elasticities, own–price elasticities and subsistence quantities for each income group across nine broadly aggregated food commodity groups. Elasticity estimates and subsistence quantity estimates differ across income groups, supporting the premise that policies targeted at specific income groups should be based on the target group's elasticity estimates rather than average population elasticities. Parameter estimates are then used to simulate how subsistence quantities and own–price elasticities can be expected to vary according to the demographic composition of the household within a specific income group.     

Nonlinear effects of oil shocks on stock returns: a Markov-switching approach

Using Markov-switching models, we investigate whether oil price shocks have nonlinear effects on stock returns. Empirical evidence from a set of international stock indexes suggests that an increase in oil prices has a negative and significant impact on stock prices in one state of the economy, whereas this effect is significantly dampened in another state of the economy. Furthermore, it is shown that changes in oil prices or in oil price volatility do not lead to a higher probability of switching between regimes.