An Error Corrected Almost Ideal Demand System for Crustaceans in the United States

We have employed an error-corrected almost ideal demand system (ECAIDS) for major crustaceans at a disaggregated level in the United States. The proposed model can provide short- and long-run price elasticities. This article makes an important empirical contribution by reporting a set of reliable, policy-relevant estimates of the elasticities of demand for crustaceans in the United States. The habit formation behavior was significant only for crayfish. The value pricing strategy and the promotional pricing strategy are expected to benefit the domestic shrimp industry. Increasing prices through various marketing strategies can benefit domestic producers of lobsters and crabs.     

A Seasonal Inverse Almost Ideal Demand System for North American Fresh Tomatoes

Increased fresh tomato trade has prompted a number of trade disputes between the United States, Canada, and Mexico. One precondition of an antidumping dispute is meeting the “likeness of product” criterion. However, fresh tomato shipments and imports are highly seasonal, suggesting that the degree of substitutability (or product likeness) may depend fundamentally on whether fresh tomato varieties are in- or out-of-season. We develop a seasonally adjusted inverse demand system using Canadian and Mexican monthly import data along with U.S. state shipping data to address both seasonality and product substitutability in the fresh tomato market. We find that market equilibrium and the degree of product substitution are affected by seasonality and product availability in the consumer choice set. Le commerce accru de la tomate fraîche suscite des différends commerciaux entre les États-Unis, le Canada et le Mexique. L'une des préconditions d'un différend en matière d'antidumping est liée au respect du critère de la « similarité du produit ». Toutefois, les expéditions et les importations de tomate fraîche sont très saisonnières, ce qui laisse supposer que le degré de substituabilité (ou de similarité du produit) puisse reposer fondamentalement sur le fait qu'il s'agisse ou non de variétés de tomate fraîche pleine saison ou hors-saison. Nous avons mis au point un système désaisonnalisé de la demande inverse utilisant des données mensuelles sur les importations canadiennes et mexicaines et des données sur les expéditions des États-Unis pour étudier la saisonnalité et la substituabilité dans le marché de la tomate fraîche. Nous sommes arrivés à la conclusion que la saisonnalité et la disponibilité des produits offerts au consommateur influent sur l'équilibre du marché et le degré de substitution du produit.     

An Almost Ideal Demand System Analysis for Meats with Habit Formation and Structural Change

In this paper, Canadian meat consumption patterns are analyzed using a dynamic version of the almost ideal demand system (AIDS). Structural change in the demand for meats is examined by testing for non-constancy of the parameters of the non-linear system. It is concluded that Canadian meat consumption patterns can be explained by a combination of habit persistence as well as changes in prices, consumer expenditures and tastes. Incorporating the dynamic element of a habit effect in the AIDS model improves the consistency between demand theory and the observed data. The hypothesis of structural change in demand during the late 1970s cannot be rejected. The detected structural shift is related to the intercept terms of the expenditure share equations, suggesting changes in taste in the demand for different meats. Consumption expenditures have shifted from beef to chicken but remained stable for pork; a 6% decline in the expenditure share of beef and a 33% increase in the expenditure share of chicken seem to have been due to this structural shift. Le présent document analyse la consommation de viande au Canada au moyen d'une version dynamique du système de la demande quasi idéale. Les auteurs examinent le change-ment structurel de la demande de viande en vérifiant si les paramètres du système non linéaire sont constants ou non. Ils en concluent que le comportement de la demande de viande au Canada peut s'expliquer à la fois par la persistence des habitudes et par les change-ments observés au niveau des prix, des dépenses des consommateurs et des goûts de ces derniers. L'intégration d'un élément dynamique au modèle, soit l'incidence des habitudes, accroît la cohérence entre la demande théorique et les observations. L'hypothèse que la demande aurait changé vers la fin des années 1970 ne peut être rejetée. La modification structurelle décelée est associée aux coordonnées à l'origine des équations de répartition des dépenses, ce qui suggère des changements de goût en ce qui concerne les différentes viandes. Ainsi, les achats de poulet ont augmenté au détriment du boeuf mais les dépenses sont restées stables pour le porc; on a observé une régression de 6 p. 100 des achats de boeuf et une hausse de 33 p. 100 de la demande de poulet, variation qui semble à l'origine du changement structurel observé.     

Demand for Domestic and Imported Table Wine in British Columbia: A Source-differentiated Almost Ideal Demand System Approach

The premium quality wine market in British Columbia has grown substantively over the past decade. However, few empirical studies exist to quantify how consumers have responded to these wines. This paper employs a source-differentiated almost ideal demand system (AIDS) model with time-varying parameters to estimate the demand for premium quality wines using scanner sales data from the British Columbia wine market. The empirical findings reveal that consumers' response to foreign-produced wines differs from that for wine produced locally. It is evident that the expenditure elasticities for British Columbia, European and Rest-of-the-World white wines are larger than those for red wines. The high expenditure elasticities associated with British Columbia white wines may suggest that these wines are associated with higher quality. We reject the hypotheses of block separability and product aggregation. There is no evidence of structural change from the tests employed in this paper.     

Using Elasticities from an Almost Ideal Demand System? Watch Out for Group Expenditure!

Group expenditure has often been treated as exogenous when estimating demand parameters for a group of commodities with an almost ideal demand system. Researchers draw demand elasticities from past literature to use in their own analysis, but elasticities contingent on exogenous group expenditure may be inappropriate. Here, the approach is considered in the case of Japanese meat demand with a simple equation added to estimate group expenditures. The results show that elasticities should be revised and that a group expenditure equation is not a panacea as it may result in the violation of theoretical restrictions, such as symmetry.     

Testing Symmetry and Homogeneity in the Almost Ideal Demand System with Co‐integrated Data using Fully Modified Estimation and the Bootstrap

Conventional seemingly unrelated estimation of the almost ideal demand system is shown to lead to small sample bias and distortions in the size of a Wald test for symmetry and homogeneity when the data are co‐integrated. A fully modified estimator is developed in an attempt to remedy these problems. It is shown that this estimator reduces the small sample bias but fails to eliminate the size distortion. Bootstrapping is shown to be ineffective as a method of removing small sample bias in both the conventional and fully modified estimators. Bootstrapping is effective, however, as a method of removing size distortion and performs equally well in this respect with both estimators.     

An application of cointegration theory in the estimation of the Almost Ideal Demand system for food consumption in Bulgaria

The Almost Ideal Demand system is applied to consumption in Bulgaria. It is argued that the conventional estimation of the Almost Ideal model should be done within the framework of contemporary time series methodology. In this paper, the canonical comtegrating regression procedure of Park is applied. It is argued that the results of the Almost Ideal Demand system that are presented are consistent with both theory and ‘casual’ observation of consumer behaviour in Bulgaria.     

Demand System Estimation with Upward-Sloping Supply

There are three important implications of this work. First, demand systems estimates that overlook supply response are as subject to simultaneous equations bias as single ad hoc demand equations. Theil shows theoretically that assuming supply curves are perfectly elastic, when in fact they are not will underestimate price responsiveness in demand equations. An empirical example is presented that demonstrates that the price elasticities generally increase when upward-sloping supplies are assumed.
Second, the iterative testing procedure presented may provide direction for model building when the true structure of the system is unknown. For example, the results of the Wu-Hausman test indicate that assuming chicken supply is perfectly elastic in a model of the Japanese livestock industry is justified. The results also indicate that the supplies of Wagyu beef, dairy beef, pork and fish are upward-sloping and therefore should be modeled as endogenous variables in the demand system.
Third, the results emphasize the sensitivity of projections of Japanese beef imports to the assumptions underlying the demand system. If perfectly elastic meat supplies are assumed for an analysis of reducing Japanese beef import liberalization, the results will likely underestimate the impacts on beef imports.
In summary, the supply curves for agricultural products tend to slope upward within the time periods used for traditional policy analysis and demand system estimation, which in turn implies that prices are determined endogenously within the system. Endogenous price determination is contrary to the assumptions that underlie the theoretical foundations and many empirical applications of demand systems. We present a methodology to test for and adjust demand systems for endogeneity. The importance of this adjustment is demonstrated by using an analysis of the liberalization of the Japanese beef market.     

北京市食用油消费调查及消费者需求偏好研究

对北京市一般食用油和高端食用油的消费现状、消费者需求偏好进行了深入研究,提出了北京市食用油企业市场发展的合理建议。一般食用油消费主要集中在花生油、大豆油和调和油,高端食用油消费主要集中在橄榄油和山茶油。一般食用油消费者偏好食用油的营养价值和功效,而高端食用油消费者偏好产品品牌。调查结果可为食用油经营者提供决策依据,为进驻食用油市场的商家提供参考。     

人口城市化对消费需求的影响分析

改革开放以来,我国经济得到了长足的发展,但消费需求不足的问题越来越突出,在一定程度上制约了我国经济的发展。城乡二元经济结构是导致消费需求不足的根本原因,城市化是解决消费需求不足的必由之路。城市化对消费增长产生收入效应、示范效应、扩张与循环累积效应等影响。本文实证分析也表明,城市化水平的提高带动了消费需求增长。因此,加快人口城市化进程,提高人口城市化率是增加我国消费需求的根本途径。     

A Family of Differential Input Demand Systems with Application to Greek Agriculture

This paper develops a family of input demand systems via alternative parametrisations of Theil's differential model. Each member of this family is as flexible as any other locally flexible functional form. More importantly, selection among the competing family members is possible via simple parameter restrictions. The family of differential input demand systems is applied to the agricultural sector in Greece for the period 1961–96. Formal tests suggest that the model with the CBS-type effects dominates the alternative models. Divisia and price elasticities are calculated from the selected model and a decomposition of changes in the demand for inputs into technical change, total input volume, substitution, and residual effects is performed. The empirical results are quite reasonable. Overall, the analysis in this paper indicates that, in certain cases, the differential approach may provide an attractive alternative to the dual approach in modelling production behaviour.     

全球钨消费历史分析及需求预测

文章基于全球钨消费增长缓慢,美国、日本和欧盟钨消费趋于平稳,中国钨需求增速放缓的背景,通过分析全球钨消费历史和消费结构,运用情景分析方法,参考"S"形消费规律,对中国及全球钨需求进行定量预测。预测到2025年全球钨需求为11万吨,2021—2030年中国钨需求为94万吨。依据我国钨基础储量数据,判断当前我国和全球钨资源供应宽松。建议保持适度钨资源供给,提升行业盈利水平。     

Efficient Estimation of Hedonic Inverse Input Demand Systems

This article is concerned with efficient estimation of characteristics demand. We derive and estimate an inverse input demand system for quality characteristics by using 172,946 observations over 881 trading days in the Icelandic fish auctions. An improved estimation method based on an expanded random coefficient model is suggested as an alternative to the currently used two-stage method of Brown and Rosen . The estimates demonstrate the improved efficiency of the suggested method. A number of empirical results emerge, including a general increase in the demand for quality.     

Food Demand in Mexico: An Application of the Amemiya-Tobin Approach to the Estimation of a Censored Food System

The modeling of micro-level food demand patterns requires not only allowing for household heterogeneity, but also addressing the problem of censoring. In this article, we present a variation of the Amemiya-Tobin framework for estimating a censored demand system that allows for household heterogeneity. The unique aspect of our approach is the use of a procedure that ensures the adding up of both latent and observed expenditure shares and also imposes expenditure share nonnegativity. This system is applied to an analysis of food demand based on a random sample of urban Mexican households.     

优化农村消费环境与扩大农民消费需求

扩大农民的消费需求是扩大内需的重要方面。目前，农民的消费需求受到阻碍的关键因素是农村的消费环境不如人意，表现在生态环境、社会文化环境和市场环境等方面，本文就此提出了优化农村消费环境的对策思路。     

Estimation of Censored Demand Equations from Large Cross-Section Data

The article develops an alternative econometric methodology to estimate a system of censored demand equations using a large cross-section data from Colombian urban households. The approach preserves the behavioral information expressed by zero expenditures and conforms with the requirements imposed by consumer theory in a way consistent with the random utility hypothesis. We motivate the choice of the Tobit model as a statistical representation of consumer behavior and introduce the methodology by specifying the AIDS model modified according to both a translating and scaling demographic transformation. We propose to estimate each demand equation in unrestricted form using the jackknife technique. We then recover the demand parameters imposing the cross-equations restrictions by using minimum distance estimation. The empirical results of the censored demand system for specific households of policy relevance are reported.     

Consistent Estimation of Censored Demand Systems Using Panel Data

We derive a joint continuous/censored commodity demand system for panel data applications. Unobserved heterogeneity is controlled for using a correlated random effects specification and a generalized method of moments framework used to estimate the model. While relatively small differences in elasticity estimates are found between a flexible random effects specification and one that restricts the random effect coefficient to be time invariant, larger differences are observed when comparing the flexible model to a pooled cross-sectional estimator. The results suggest the limited ability of such estimators to control for preference heterogeneity and unit-value endogeneity leads to parameter bias.     

Demand Estimation in the Presence of Stochastic Trend and Seasonality: The Case of Meat Demand in the United Kingdom

If budget shares have stochastic trend or seasonality or both, then demand equations based on the assumption of deterministic trend and deterministic seasonality will be mis-specified. We test this proposition by estimating a Linearized Almost Ideal (LAI) demand system for meat demand in the United Kingdom using Harvey's structural time series methodology. We demonstrate that the model specification allowing for stochastic trend and deterministic seasonality performs best in terms of diagnostic tests and goodness of fit measures. It is also shown that the model with stochastic trend is better at out-of-sample forecasting.