A Dual Approach to Nonconvex Frontier Models

This paper extends the links between the non-parametric data envelopment analysis (DEA) models for efficiency analysis, duality theory and multi-criteria decision making models for the linear and non-linear case. By drawing on the properties of a partial Lagrangean relaxation, a correspondence is shown between the CCR, BCC and free disposable hull (FDH) models in DEA and the MCDM model. One of the implications is a characterization that verifies the sufficiency of the weighted scalarizing function, even for the non-convex case FDH. A linearization of FDH is presented along with dual interpretations. Thus, an input/output-oriented model is shown to be equivalent to a maximization of the weighted input/output, subject to production space feasibility. The discussion extends to the recent developments: the free replicability hull (FRH), the new elementary replicability hull (ERH) and the non-convex models by Petersen (1990). FRH is shown to be a true mixed integer program, whereas the latter can be characterized as the CCR and BCC models.     

住房抵押贷款定价模型与数值分析

期权的价值取决于借款人的违约行为和提前偿还行为,而借款人的违约行为和提前偿还行为又取决于当前的利率水平和房屋价格。CTR模型表明,住房抵押贷款合同的价值满足一个偏微分方程。运用交替方向隐性有限差分法对住房抵押贷款合同的价值进行数值分析的结果表明,由于提前偿还期权和违约期权的存在,贷款合同的价值远远小于贷款总额。房屋价格的波动幅度与抵押贷款合同的价值负相关,而利率波动幅度与抵押贷款合同的价值正相关。为减少商业银行面临的提前偿还风险和违约风险,住房抵押贷款合同需要使用浮动利率贷款,同时还应加快发展我国住房抵押贷款保险市场。     

Detecting Outliers in Frontier Models: A Simple Approach

In frontier analysis, most of the nonparametric approaches (DEA, FDH) are based on envelopment ideas which suppose that with probability one, all the observed units belong to the attainable set. In these deterministic frontier models, statistical theory is now mostly available (Simar and Wilson, 2000a). In the presence of super-efficient outliers, envelopment estimators could behave dramatically since they are very sensitive to extreme observations. Some recent results from Cazals et al. (2002) on robust nonparametric frontier estimators may be used in order to detect outliers by defining a new DEA/FDH deterministic type estimator which does not envelop all the data points and so is more robust to extreme data points. In this paper, we summarize the main results of Cazals et al. (2002) and we show how this tool can be used for detecting outliers when using the classical DEA/FDH estimators or any parametric techniques. We propose a methodology implementing the tool and we illustrate through some numerical examples with simulated and real data. The method should be used in a first step, as an exploratory data analysis, before using any frontier estimation.     

Interpolation of Air Quality Measures in Hedonic House Price Models: Spatial Aspects

Abstract

This paper investigates the sensitivity of hedonic models of house prices to the spatial interpolation of measures of air quality. We consider three aspects of this question: the interpolation technique used, the inclusion of air quality as a continuous vs discrete variable in the model, and the estimation method. Using a sample of 115,732 individual house sales for 1999 in the South Coast Air Quality Management District of Southern California, we compare Thiessen polygons, inverse distance weighting, Kriging and splines to carry out spatial interpolation of point measures of ozone obtained at 27 air quality monitoring stations to the locations of the houses. We take a spatial econometric perspective and employ both maximum-likelihood and general method of moments techniques in the estimation of the hedonic. A high degree of residual spatial autocorrelation warrants the inclusion of a spatially lagged dependent variable in the regression model. We find significant differences across interpolators in the coefficients of ozone, as well as in the estimates of willingness to pay. Overall, the Kriging technique provides the best results in terms of estimates (signs), model fit and interpretation. There is some indication that the use of a categorical measure for ozone is superior to a continuous one.

RÉSUMÉ

Interpolation des Mesures de la Qualité de l'Air dans les Modèles Hédoniste de l'Estimation Immobilière: Aspects Spatiaux

Cet article examine la sensibilité de l’évaluation hédoniste des prix de l'immobilier à l'interpolation spatiale des mesures de la qualité de l'air. Nous avons envisagé la question sous trois aspects: la technique d'interpolation utilisée, l'introduction de la qualité de l'air comme variable continue ou discrète dans le modèle et la méthode d'estimation. Nous avons utilisé un échantillon de 115 732 ventes de maisons individuelles, en 1999, dans le district Côte Sud de la gestion de la Qualité de l'Air en Californie du Sud. Nous avons comparé les polygônes de Thiessen, la pondération inversement proportionnelle à la distance, le krigeage et les courbes splines pour mener l'interpolation des mesures ponctuelles de l'ozone, obtenues dans 27 stations de suivi de la qualité de l'air en fonction des lieux où étaient situées les maisons. Nous avons pris une perspective spatiale économétrique et employé aussi bien la probabilité maximale que la méthode générale des moments techniques dans l’évaluation de l'hédonique. Un degré élevé d'auto corrélation spatiale résiduelle garantie l'inclusion d'une variable dépendante spatialement décalée dans le modèle de régression. Nous avons trouvé des différences importantes parmi les interpolateurs dans les coefficients d'ozone, ainsi que parmi les indicateurs de la volonté de payer. Surtout, la technique de krigeage donne les meilleurs résultats pour les estimations (signes), l'ajustement du modèle et l'interprétation. L'utilisation d'une mesure nominale pour l'ozone est supérieure à une mesure continue, semble-t-il.

RESUMEN

Interpolación de las medidas de la calidad del aire en los modelos de los precios hedónicos de la vivienda: aspectos espaciales

En este ensayo investigamos la sensibilidad de los modelos de lo precios hedónicos de la vivienda para la interpolación espacial de medidas de la calidad del aire. Tenemos en cuenta tres aspectos al respecto: la técnica de interpolación utilizada, la inclusión de la calidad del aire como variable continua, en vez de discreta, en el modelo, y el método de cálculo. Con una muestra de 115.732 ventas de viviendas individuales durante 1999 en el Distrito de Gestión de Calidad del Aire de la Costa Sur en California, comparamos los polígonos de Thiessen, la ponderación de la distancia inversa, métodos geoestadísticos o Kriging y métodos basados en splines para llevar a cabo la interpolación espacial de las mediciones puntuales de ozono obtenidas en 27 estaciones de control de calidad del aire en los lugares donde están situadas las viviendas. Desde la perspectiva econométrica espacial empleamos las técnicas de la probabilidad máxima del método general de momentos en el cálculo de precios hedónicos. Debido a un alto grado de autocorrelación espacial residual debemos incluir una variable dependiente espacialmente rezagada en el modelo de regresión. Se observan diferencias importantes entre los interpoladores en los coeficientes del ozono y en los cálculos de la disposición a pagar. En general, la técnica Kriging da los mejores resultados en cuanto a los cálculos (señales), la idoneidad del modelo y la interpretación. Hay indicios de que es mejor usar una medida categórica para el ozono en vez de una continua.     

Simple,Efficient and Distribution-free Approach to Interaction Effects in Complex Structural Equation Models

Structural equation models with mean structure and non-linear constraints are the most frequent choice for estimating interaction effects when measurement errors are present. This article proposes eliminating the mean structure and all the constraints but one, which leads to a more easily handled model that is more robust to non-normality and more general as it can accommodate endogenous interactions and thus indirect effects. Our approach is compared to other approaches found in the literature with a Monte Carlo simulation and is found to be equally efficient under normality and less biased under non-normality. An empirical illustration is included.     

Using Non-linear Models for a Complexity Approach to Psychological Well-being

Psychological well-being in adolescence is an increasing field of study. The literature identifies a large number of dimensions of psychological well-being. However, even when considering all these dimensions, the explanatory power of most models is rather low. Complexity theories can be a productive alternative, at the theoretical but especially the methodological level, to the limitations more traditional approaches to psychological well-being have. In this paper, we suggest a structural equation modelling approach to complexity that focuses on the non-linearity property. Given the large number of dimensions, the model is estimated in two steps as described by Jöreskog [(2000) Latent Variable Scores and Their Uses. Lincolnwood IL: Scientific Software International] First, a confirmatory factor analysis is fitted and Anderson and Rubin’s factor scores are saved. Then all possible products and squared terms of the factor scores are computed and are used as predictors of the dependent variable using an ordered logit model. The results from a sample of 968 Catalan adolescents show that a non-linear model including interaction effects among the eight dimensions, age and gender, has a higher explanatory power to predict satisfaction with life as a whole, compared to a linear model. Important consequences for the study of psychological well-being in adolescence emerge from the methodological procedure we have followed, which can be used to study any type of complex psychological and psychosocial phenomenon.     

The Expectations Hypothesis of the Term Structure and Time-Varying Risk Premia: a Panel Data Approach

One implication of the expectations hypothesis is that the yield spread should forecast subsequent changes in the long yield. However, regression tests based on this specification strongly reject the expectations hypothesis. One explanation for this rejection is that these tests fail to allow for a time varying risk premium that is correlated with this yield spread, leading to a bias in the estimated regression coefficients. This paper uses panel data in order to testm the expectations hypothesis under the assumption that risk premia are time-varying but driven by a single factor. It is found that while the expectations hypothesis is still rejected, the bias in the estimated coefficient is verysubstantially reduced.     

Technology Transfer to China: A Theoretical Approach

SUMMARY

Various economic theories can be used to shed some light on the complex phenomenon of technology transfer between two firms belonging to two distinct economies. Vernon's PLC model, Dunning's eclectic theory, and Coase's and Williamson's transaction cost theory highlight various aspects of the firm's transnational economic and business relations. Moreover, the new international trade theories and the more modern concept of National Innovation System emphasize technology as a crucial variable in the determination of commercial flows and of economic growth. Our theoretical approach goes beyond these various approaches in that it is designed to reflect the complexities of the economic, socio-cultural and political conditions prevailing in the recipient country. In particular, the ability of recipient countries to use their bargaining power is highlighted. The case of technology transfer in the Chinese telecommunications equipment industry will illustrate our general framework.     

GARCH族模型的预测能力比较:一种半参数方法

半参数GARCH模型无须设定条件分布的具体形式。本文首先将一种效率较高、易于实施的半参数方法——估计函数方法应用于10类常见的GARCH结构,并给出证据,显示该方法能显著提高GARCH族模型的波动率预测绩效。然后,应用估计函数方法,较为全面地比较各类GARCH结构的预测能力。为给出统计意义下的结果,并减少数据窥察问题,研究中分别使用OLS和SPA检验法进行绩效评价。结果发现,与其他GARCH类结构相比,EGARCH和APARCH模型能够较好地描述股市收益率的波动过程。     

Introducing Environmental Variables in Nonparametric Frontier Models: a Probabilistic Approach

This paper proposes a general formulation of a nonparametric frontier model introducing external environmental factors that might influence the production process but are neither inputs nor outputs under the control of the producer. A representation is proposed in terms of a probabilistic model which defines the data generating process. Our approach extends the basic ideas from Cazals et al. (2002) to the full multivariate case. We introduce the concepts of conditional efficiency measure and of conditional efficiency measure of order-m. Afterwards we suggest a practical way for computing the nonparametric estimators. Finally, a simple methodology to investigate the influence of these external factors on the production process is proposed. Numerical illustrations through some simulated examples and through a real data set on Mutual Funds show the usefulness of the approach.JEL Classification: C13, C14, D20     

成本管理新模式——Kaizen成本制度

Kaizen成本制度是日本的Kaizen企业文化在成本管理上的具体体现。本文对Kaizen成本制度的涵义、主要特点、基本步骤、目标确定和业绩评价进行了系统的介绍,对半生命周期模型在成本改进中的运用进行了探讨,分析比较了Kaizen成本制度与标准成本管理、成本企画之间的关系,并就这种成本制度实施过程中可能遇到的适用范围、组织文化等问题进行了讨论。     

The Estimable Functions of Age, Period and Generation Effects: A Political Application

In traditional social research, it is customary to assume that the birth cohort, period and age are scaled as follows: cohort = period – age. Starting from this constraint, the joint analysis of the three effects is not estimable, as one phenomenon is completely determined by the remaining two. In this study we will see how, in given situations, the use of the concept of political generation, to replace the cohort concept normally used, allows us to overcome this obstacle and how in this case estimable models may easily be created.     

The Impact of Manufactured Housing on Adjacent Residential Property Values: A GIS Approach Based on Three North Carolina Counties

This empirical study examines the impact of manufactured housing (MH) on the values of adjacent site-built residential properties using Geographical Information Systems (GIS) and large data samples for three counties in North Carolina, USA, for the period of 1994-2000. Both property appreciation rates (AR) and property values (PV) are examined with respect to proximity to MH. While ARs are based on a simple measure of value appreciation, PVs are estimated in a linear regression based hedonic price model, which is designed to captures the contributions of structure and location attributes to property values. Results indicate that the appreciation rates slightly decreased with distance from a MH unit in Buncombe and Wake, but the reverse is true in Pitt. The statistical analyses reveal that proximity to a manufactured home influences the value of nearby site-built residential property. Estimated property values show that the further away from a manufactured home, the higher the site-built property value, other things being equal.     

A Switching Regime Approach to Measuring the Effects of Technological Change in Ocean Shipping

this study examines the dramatic change in production technology of the U.S. ocean liner shipping industry over the period 1971 through 1982 using panel data on 15 subsidized U.S.-flag liner firms. To estimate the changes in the production function due to the new technology, the switching regime method of Goldfeld and Quandt is applied to a translog variable profit function. Three regimes based on the proportion of the new technology reflected in a firm's fleet are identified. The constant returns to scale fleet size more than doubles across the three regimes.     

A Note on Estimated Coefficients in Random Effects Probit Models

This note points out to applied researchers what adjustments are needed tothe coefficient estimates in a random effects probit model in order to make valid comparisons in terms of coefficient estimates and marginal effects across different specifications. These adjustments are necessary because of the normalization that is used by standard software in order to facilitate easyestimation of the random effects probit model.