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     

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.     

An Almost Ideal Cost of Living Index for Food in Spain Using a Microeconomic Approach and Censored Data

Abstract

A true cost of living (COL) index should compare the cost derived by two consumption levels and two price vectors maintaining the same utility in the two cases. Its application and empirical testing has been, generally, focalized on a temporal perspective. A spatial perspective it is also interesting for economic analysis because it allows for making comparisons of COLs across geographical units. This spatial approach, however, it is not so frequent in the literature. The aim of this paper is to calculate a spatial COL index for the regions of Spain. For this purpose, we use microdata from the 2010 Households Budget Survey (HBS, Encuesta de Presupuestos Familiares) provided by the Spanish Statistical Institute (INE, Instituto Nacional de Estadística). We will denominate this index spatial cost of living index (SCOL). We use a microeconomic approach that keeps the level of utility of households constant across space but allows for substitution among different baskets of goods. The results reveal large differences in COL across the Spanish regions. The estimates of the SCOL index allows for reconsidering regional comparisons in terms of average wages. Even when nominal monetary figures from official Regional Accounts show huge regional disparities, regional differences are largely moderated when the wage figures are corrected by our SCOL index.     

经济发展、危险行为与艾滋病传播

经济发展通过影响人们的危险（易感）行为来影响艾滋病的传播。本文提出的一个简单两时期代际模型表明：随着经济发展,个人财富的增加提高人们对于未来生活的预期,这将抑制人们的危险行为;但经济发展带来的应对疾病能力的提高又会增加人们的类似行为。因此,经济发展对于艾滋病传播的最终影响具有不确定性。本文在此基础上对中国各地区的艾滋病发病率进行检验,确实发现经济发展对艾滋病传播的影响不显著,个人财富确实抑制了艾滋病的流行,但未发现公共医疗水平提高对于艾滋病传播有显著正影响。     

艾滋病与普通服刑人员心理健康状况比较研究

以清流监狱服刑人员为调查对象,采用SCL-90症状自评量表对64名艾滋病服刑人员和普通服刑人员进行心理健康状况调查,结果表明：普通服刑人员和艾滋病服刑人员都存在比较普遍的心理健康问题,总均分都显著高于全国常模群体;二者相比较,艾滋病服刑人员在总均分和躯体化、强迫、人际关系、抑郁、焦虑、恐怖6个因子上存在更加严重的问题。因此,监狱应重视服刑人员的心理健康教育,特别是对艾滋病服刑人员要给予特别的关心和帮助,尽可能提高艾滋病服刑人员的心理健康水平。