Environmental impacts of fat blends

Environmental Life Cycle Analysis (LCA) has emerged over the past years as a method to assess environmental impacts of products and processes. In this case study we use LCA to obtain an environmental measure for refined oils, which are inputs for fat blends. As a start, an inventory is drawn up of the environmental effects of the oils. Then we use the Analytic Hierarchy Process (AHP) to aggregate the scores of these effects to one environmental index for each oil. This multiple criteria decision tool involves making pairwise comparisons between the environmental effects, resulting in relative weight factors. Multiplying the effect scores with the relative weights yields an environmental index. It is now possible to improve the environmental impact of a fat blend composition using the environmental index in a linear programming (LP) blending model. With this combination of methods, environmental aspects of products can become part of product portfolio management.     

Revisiting the Link Between Stock Prices and Goods Prices in OECD Countries

Fisher hypothesis postulates positive relation between stock return and inflation; however early studies document negative relationship between the two and they conclude that stock cannot be used as a hedge against inflation. In this paper we explore long‐run nonlinear relationship between stock price and goods price. Our sample consists of 19 OECD countries; all or some of these countries have been studied before with the findings of linear cointegration between the stock index and goods price index. Based on unit root tests and linear cointegration test, we apply threshold cointegration tests, Autoregressive Distributed Lag (ARDL) cointegration test and panel VAR method. With all these econometric methods we arrive at heterogeneous findings as follows: two countries have linear cointegration, five countries have threshold cointegration, nine countries do not have any cointegration and finally two countries provide inconclusive results. Estimates of Fisher coefficient provided by linear and nonlinear cointegration methods, which range between 1.27 and 1.86, are consistent with previous studies. Impulse response analysis from panel VAR for countries having no cointegrating relation shows that shock to inflation produces negative response in stock return, which supports findings of earlier studies.     

Contemporaneous and long run canonical correlations in the linear IV model: Implications for instrument selection

In the normal linear simultaneous equations model, we demonstrate a close relationship between two recently proposed methods of instrument selection by presenting a fundamental relationship between the two sets of canonical correlations upon which the methods are based.     

Similarity in trade structures,integration and catching‐up1

In this paper, we look at the role of export composition in the growth process, considering how increased similarity in trade structure among countries can induce catching‐up in income levels in a group of countries in transition. We analyze the sectoral export patterns of the Central and Eastern European countries (CEECs) by comparing them to those of the current members of the European Union (EU), focusing on countries’ specialization as suppliers for the EU market, and we assess whether similar export patterns foster the catching‐up process of the CEECs. Our main result is that similarity in export composition has a positive, significant and non‐linear impact on catching‐up, and seems to be driven by the growth of the main export market and delocalization of production more than by other factors.     

Semi-parametric models for satisfaction with income

An overview is presented of some parametric and semi-parametric models, estimators, and specification tests that can be used to analyze ordered response variables. In particular, limited dependent variable models that generalize ordered probit are compared to regression models that generalize the linear model. These techniques are then applied to analyze how self-reported satisfaction with household income relates to household income, family composition, and other background variables. Data are drawn from the 1998 wave of the German Socio-Economic Panel. The results are used to estimate equivalence scales and the cost of children. We find that the standard ordered probit model is rejected, while some semi-parametric specifications survive specification tests against nonparametric alternatives. The estimated equivalence scales, however, are often similar for the parametric and semi-parametric specifications.JEL Classification: C14, C35, D12Correspondence to: Charles BellemareWe are grateful to an anonymous referee and to participants of a CeMMAP/ESG workshop at University College London and seminars at CentER (Tilburg University) and Humboldt University Berlin for useful comments.     

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.     

金融危机后物流产业绿色化发展战略研究——基于国家竞争优势的视角

以减少物流成本以及增加产业增加值为目标的绿色物流无疑是金融危机后我国物流产业发展的最佳选择之一。运用线性回归方法进行分析可得出物流成本、物流增加值与国家经济发展水平具有相关关系。在基于国家竞争优势与＂物流产业钻石模型＂的基础上,得出物流绿色化发展战略,其中包括从绿色物流需求条件到政府行为等五个方面。     

线性回归模型参数线性约束检验的Eviews实施

线性回归模型是计量经济模型的主要形式,其参数除了需要显著性检验和方程显著性检验外,有时还需要对其参数线性约束条件的检验。本文介绍运用Eviews软件对模型参数线性约束的F检验、沃尔德检验与t检验三种方法。     

BREAKING THE GLASS CEILING: SLOW PROGRESS AHEAD

Studies show that the percentage of female senior managers in large corporations continues to grow slowly. I consider a firm that initially has an entirely male management structure. If this firm suddenly shifts its behavior and begins to hire male and female managers in equal numbers and treats them equally, then the gender composition of the firm's managers will change over time. Using well‐established mathematical methods, I derive equations that show how rapidly this change will occur. Using data from previously published studies to establish parameter bounds, I draw random samples for parameter values and use these to investigate how quickly the gender composition of a firm's management structure can change. I find that the gender composition at lower management levels changes quickly, compared to the upper management levels. (JEL J71)     

Distributive and Additive Costsharing of an Homogeneous Good

Individual users demand different quantities of a homogeneous good produced under variable returns. We describe the family of costsharing methods that allocate costs in proportion to demands when returns are constant, and commute with the additivity and composition of cost functions. Two simple such methods are average cost pricing and incremental costsharing. All other methods in the family combine elements of the average cost and incremental ones. Serial costsharing stands out prominently in the family, whereas the Shapley–Shubik method, and all values from the associated stand alone cooperative game, are excluded.Journal of Economic LiteratureClassification Numbers: D63, C71.     

The Distribution and Composition of Personal Sector Wealth in Australia

This article begins by noting the scarcity of information on the distribution of wealth in Australia, and the many reasons for wanting to have such information. The potential role of the tax system in affecting the composition of wealth is noted, and the taxation of savings is briefly described. A number of different methods of estimating the distribution of wealth are discussed. Estimates for the distribution and composition of wealth in Australia in 1986 are derived from the 1986 Income Distribution Survey, which suggest that the wealthiest ten per cent of income units hold 55 per cent of total wealth. The composition of wealth is broadly consistent with the expected impact of the tax system.     

Non‐Linear Pricing and Price Indexes: Evidence and Implications from Scanner Data

Non‐linear pricing, the fact that prices do not necessarily change in proportion to size, is a ubiquitous phenomenon. However, it has been neither particularly well understood nor well measured. Non‐linear pricing is of practical importance for statistical agencies who, in constructing price indexes, are often required to compare the relative price of a product‐variety of two different sizes. It is usually assumed that prices change one‐for‐one with package and pack size (e.g. a 1‐liter cola costs half as much as a 2‐liter bottle). We question the wisdom of such an assumption and outline a model to flexibly estimate the price‐size function. Applying our model to a large U.S. scanner dataset for carbonated beverages, at a disaggregated level, we find very significant discounts for larger‐sized products. This highlights the need to pursue methods such as those advocated in this paper.     

Variable selection and estimation in high‐dimensional models

Models with high‐dimensional covariates arise frequently in economics and other fields. Often, only a few covariates have important effects on the dependent variable. When this happens, the model is said to be sparse. In applications, however, it is not known which covariates are important and which are not. This paper reviews methods for discriminating between important and unimportant covariates with particular attention given to methods that discriminate correctly with probability approaching 1 as the sample size increases. Methods are available for a wide variety of linear, nonlinear, semiparametric and nonparametric models. The performance of some of these methods in finite samples is illustrated through Monte Carlo simulations and an empirical example.     

Model selection for nonlinear time series

We investigate the finite-sample performance of model selection criteria for local linear regression by simulation. Similarly to linear regression, the penalization term depends on the number of parameters of the model. In the context of nonparametric regression, we use a suitable quantity to account for the Equivalent Number of Parameters as previously suggested in the literature. We consider the following criteria: Rice T, FPE, AIC, Corrected AIC and GCV. To make results comparable with other data-driven selection criteria we consider also Leave-Out CV. We show that the properties of the penalization schemes are very different for some linear and nonlinear models. Finally, we set up a goodness-of-fit test for linearity based on bootstrap methods. The test has correct size and very high power against the alternatives investigated. Application of the methods proposed to macroeconomic and financial time series shows that there is evidence of nonlinearity.First version received: September 2002/Final version received : October 2003I would like to thank Cees Diks, Cars Hommes and an anonymous referee for useful comments that significantly improved the paper.     

Environmental impacts of China's WTO-accession

China's accession to the WTO in 2001 completed the country's entry into the global economy. We investigate environmental implications of WTO-accession. There are several hypotheses in this area: The scale hypothesis says that production is scaled up and in turn, pollution increases. The technique hypothesis says that production methods become cleaner and pollution decreases. The composition hypothesis says that composition of industries changes and pollution reflects the new composition. We analyse the relative strength of the hypotheses by means of an environmental CGE-model, and in the case of air pollution find support for a composition effect in favour of clean industries. Thanks to the composition effect, emissions to air of greenhouse gases fall. Emissions of particles and SO₂ also fall, but emissions of NO_x and VOC rise. Since particle and SO₂-emissions fall we estimate that public health improves.     

The separability axiom and equal-sharing methods

A quasi-linear social choice problem is defined as selecting one (among finitely many) indivisible public decision and a vector of monetary transfers among agents to cover the cost of this decision. This decision is based upon individual preferences, which are assumed to be additively separable and linear in money. The Separability axiom is a consistency property for choice methods on societies with variable size: the decision is not affected if we remove an arbitrary agent under the condition that he be guaranteed his original utility level and the cost to the remaining agents is modified accordingly. Thus the utility level assigned by the social choice function to agent i is the price at which the other agents are unanimously willing to buy agent is share of the decision power. A general characterization of choice methods satisfying this axiom is provided. Three subclasses of particular interest are characterized by additional milder axioms. Those are: (i) equal sharing of the surplus left over some reference utility (e.g., the utility at a status quo decision), (ii) utilitarian methods that merely select the efficient public decision and perform no monetary transfers, and (iii) equal allocation of nonseparable costs, which divides equally the surplus left over from the utility derived from the pivotal mechanism (also known as the Vickrey-Clarke-Groves mechanism).     

避孕知情选择对中国人工流产的影响分析

随着避孕知情选择的逐步展开,我国已婚育龄人群的避孕模式发生了较大变化。其中,短效自控型避孕措施构成的升高,减弱了原来以长效医控型避孕措施为主的避孕模式所固有的高避孕效果,也增加了意外妊娠的可能性。人工流产作为意外妊娠的主要补救措施,其发生的可能性是否随知情选择的开展而有所变化?目前,鲜有学者对此进行过全国层面的系统量化分析。利用1988～2001年全国计划生育/生殖健康抽样调查数据,比较知情选择开展前后人工流产行为的变化。伴随知情选择的全面展开,已婚育龄妇女人工流产发生可能性降低的趋势在各个孩次上都有明显的体现,表明我国知情选择的逐步推广已产生了一定的良性效果。     

Comparison of alternative methods of updating Input-Output tables: A note

Various methods for updating Input-Output tables have been proposed and comparisons have been made on statistical bases. In this note we show on theoretical bases that several linear programming formulations are not suitable to this problem, since a large proportion of the resulting coefficients assume arbitrarily preset values.     

Semiparametric Estimation of Simultaneous-Equation Microeconometric Models with Index Restrictions

This article introduces semiparametric methods for the estimation of simultaneous-equation microeconometric models with index restrictions. The methods are motivated by a semiparametric minimum-distance procedure, which unifies the estimation of both regression-type and linear or nonlinear simultaneous-equation models without emphasis on the construction of instrumental variables. Single-equation and systematic estimation methods and optimal weighting procedures are considered. The estimators are √ n -consistent and asymptotically normal. For the estimation of nonparametric regression and some sample selection models where the variances of disturbances are functions of the same indices, the optimal weighted estimator attains Chamberlain's efficient bound for models with conditional moment restrictions. The weighted estimator is shown to be optimal within a class of semiparametric instrumental variables estimators.
JEL classification numbers: C14, C24, C34.     

生态水利工程系统服务功能的评价方法与指标体系建立

本文从了解生态服务功能的内涵出发，主要讨论对生态水利工程系统的服务功能的评价方法的选择、评价指标体系的种类以及评价指标体系的具体项目组成情况。