基于农村物流需求量的组合预测分析

农村物流需求量的预测对于农村物流的发展有重要意义。文章把农村消费品零售总额作为农村物流需求量预测指标．通过分析各影响因素,建立了多元回归、双指数平滑及移动平均单预测模型。根据得出的单项预测误差数据,采用折扣系数法建立组合预测模型,使得组合预测模型预测误差平方和最小。预测能力明显优于单项预测模型。     

The Lowest Supply and Demand of Engineering Officers of National Vessels in Taiwan

This article is based on the number of engineering officers from 1994 to 2000 in Taiwan, and adopts a 6-year moving average to work out the transition probability of engineering officers and to construct an absorbing Markov Transition Matrix to forecast the terms of seniority and annual supply in each hierarchy. In order to estimate the minimum number of vessels needed, this article also employed the quantity of demand for imported consumer goods from 1994 to 2000 in Taiwan and applied a Grey model to predict the annual quantity of demand for imported consumer goods. Furthermore, this article estimated the minimum number of demand for engineering officers according to the minimum number of vessels needed. In addition, this paper used cross-analysis to investigate the manpower supply and demand of engineering officers in Taiwan and obtained some important results, which can be valuable references for pertinent authorities.     

Valuing intangible assets with a nested logit market share model

This paper develops an econometric method for valuing intangible assets using nested logit market share assumptions. Specifically, a method is developed to measure the value to a license holder of owning a branded consumer product. While it is well known that brands confer values to their owners, existing methods for establishing a brand's value via comparable, profit, or income methods are often fraught with imprecision or are frequently based on untested assumptions. An economic approach to brand valuation is developed in which the demand for branded goods is estimated and compared to the demand for comparable unbranded goods including both private label and generic commodities. The economic analysis relies on oligopoly pricing models and certain assumptions regarding the opportunity use of the brand holder's fixed investment. This paper extends the multinomial logit structure of preferences assumed in Dubin [1998a. The Demand for Branded and Unbranded Products—An Econometric Method for Valuing Intangible Assets. Studies in Consumer Demand—Econometric Methods Applied to Market Data. Kluwer Academic Publishers, Massachusetts, Boston, pp. 77–127] and derives trademark valuation fractions with a nested logit market share model. The market share demand model in Dubin [1998a. The Demand for Branded and Unbranded Products—An Econometric method for Valuing Intangible Assets. Studies in Consumer Demand—Econometric Methods Applied to Market Data. Kluwer Academic Publishers, Massachusetts, Boston, pp. 77–127] is re-estimated under nested logit assumptions and results for the trademark fraction are compared.     

Increasing the price variation in a repeated cross section

Insufficient price variation seriously hampers many applications of consumer demand models. This paper examines the empirical performance of a potential remedy for this problem that was suggested by [Lewbel, A., 1989. Identification and estimation of equivalence scales under weak separability. Review of Economic Studies 56, 311–316], the construction of individual specific price indices for bundles of goods. These individual specific price indices allow for a population with heterogeneity in preferences for goods within a given bundle of goods. We confine ourselves to heterogeneous Cobb Douglas within bundle preferences, while between bundles, we allow for several parametric and even general nonparametric specifications. In a variety of settings, we show that such prices produce superior empirical results than the ones obtained through the traditional practice of using aggregate price indices. Our empirical analysis is based on the British Family Expenditure Survey data, and uses several categories of food. Both in parametric as well as nonparametric models, we obtain higher precision of estimates for parameters or functions, as well as economically more plausible results.     

COMPARING ALTERNATIVE MODELS OF HETEROGENEITY IN CONSUMER CHOICE BEHAVIOR

When modeling demand for differentiated products, it is vital to adequately capture consumer taste heterogeneity, But there is no clearly preferred approach. Here, we compare the performance of six alternative models. Currently, the most popular are mixed logit (MIXL), particularly the version with normal mixing (N‐MIXL), and latent class (LC), which assumes discrete consumer types. Recently, several alternative models have been developed. The 'generalized multinomial logit' (G‐MNL) extends N‐MIXL by allowing for heterogeneity in the logit scale coefficient. Scale heterogeneity logit (S‐MNL) is a special case of G‐MNL with scale heterogeneity only. The 'mixed‐mixed' logit (MM‐MNL) assumes a discrete mixture‐of‐normals heterogeneity distribution. Finally, one can modify N‐MIXL by imposing theoretical sign constraints on vertical attributes. We call this 'T‐MIXL'. We find that none of these models dominates the others, but G‐MNL, MM‐MNL and T‐MIXL typically outperform the popular N‐MIXL and LC models. Copyright © 2012 John Wiley & Sons, Ltd.     

Comparing forecasts from fixed and variable coefficient models: The case of money demand

In this paper we introduce a class of tentatively plausible, fixed-coefficient models of money demand and evaluate their forecast performance. When these models are reestimated allowing all coefficients to vary over time, the forecasting performance improves dramatically. Aside from offering insights about improved methods of analyzing time series data, the most promising direct use for point estimates derived from time-varying coefficients is as an aid in calibrating proposed models of the kind discussed here.     

Demand for durable and nondurable goods,environmental policy and consumer welfare

If a tax on energy affects the demand for a nondurable good, the stock of a durable good, and the proportion of the energy consumption per unit of service of the durable good, an integrated approach for investigating consumer demand for durables and nondurables is required. The purpose of this paper is to employ the concept of a variable expenditure function with quasi-fixed durable goods as arguments in order to derive a demand system for nondurable goods in prices of the nondurables, in the stocks of durables, and in variable expenditure. From the envelope condition desired stocks of durables can be calculated and investment demand for durables can be determined. For an application we choose a variable expenditure function based on the almost ideal demand specification, and evaluate alternative environmental policy measures using the equivalent variation for comparing the welfare effects.     

新奢侈品的细分市场及消费者行为研究

本文在文献研究、理论分析的基础上,将新奢侈品定义为外形识别度高、具有适度品牌溢价的优质消费品,并总结了新奢侈品的特点及发展趋势;识别了目标消费者群体所在的心理学、人文的细分市场,以及分析了新奢侈品的需求曲线;在上海地区调研的基础上,总结了消费新奢侈品的产品偏好、品牌偏好。     

河南农村物流需求的组合预测及策略研究

河南作为农业大省大力发展农村物流对其率先实现中部崛起有着很重要的现实意义,预测河南农村物流需求对于制定发展战略显得尤为重要。文中以河南农村消费品零售总额为河南农村物流需求预测指标,综合一元线性回归、时间序列双指数平滑法、移动平均法,建立组合预测模型,追求预测误差平方和最小,预测出河南农村物流需求呈良性发展趋势,并就进一步发展河南农村物流提出建议。     

Predicting default risk under asymmetric binary link functions

In this article we propose the use of an asymmetric binary link function to extend the proportional hazard model for predicting loan default. The rationale behind this approach is that the symmetry assumption that has been widely used in the literature could be considered as quite restrictive, especially during periods of financial distress. In our approach we allow for a flexible level of asymmetry in the probability of default by the use of the skewed logit distribution. This enable us to estimate the actual level of asymmetry that is associated with the data at hand. We implement our approach to both simulated data and a rich micro dataset of consumer loan accounts. Our results provide clear evidence that ignoring the actual level of asymmetry leads to seriously biased estimates of the slope coefficients, inaccurate marginal effects of the covariates of the model, and overestimation of the probability of default. Regarding the predictive power of the covariates of the model, we have found that loan-specific covariates contain considerably more information about the loan default than macroeconomic covariates, which are often used in practice to carry out macroprudential stress testing.     

我国输欧消费品技术性贸易壁垒的新进展

2004～2009年,欧盟对华产品通报始终位居RAPEX系统首位。2009年,欧盟发布对华通报1993项,相比2008年增幅达7％。2009年,欧盟连续发布多项关于消费品和消费品中化学物质的安全指令,我国输欧消费品面临的技术性贸易壁垒形势愈加严峻。文章在统计和分析欧盟RAPEX对华产品通报新进展的基础上,围绕2009年欧盟新出台的法规与指令展开研究,综合分析了导致我国输欧消费品遭受技术性贸易壁垒的多方面因素,最后提出了应对策略与建议。     

Demand and supply estimation biases due to omission of durability

We build a dynamic equilibrium model of a durable goods oligopoly with a competitive secondary market to evaluate the bias in estimating the structural parameters of demand and supply when durability is omitted. We simulate data from our dynamic model and use them to estimate the model’s static counterpart. We find that the static estimate of the elasticity of demand is an overestimate of the true elasticity and that the static estimate of the markup is an underestimate. Our results provide a benchmark on the magnitude and sign of the bias when static models are used for economic inference.     

Probabilistic forecasting of heterogeneous consumer transaction–sales time series

We present new Bayesian methodology for consumer sales forecasting. Focusing on the multi-step-ahead forecasting of daily sales of many supermarket items, we adapt dynamic count mixture models for forecasting individual customer transactions, and introduce novel dynamic binary cascade models for predicting counts of items per transaction. These transaction–sales models can incorporate time-varying trends, seasonality, price, promotion, random effects and other outlet-specific predictors for individual items. Sequential Bayesian analysis involves fast, parallel filtering on sets of decoupled items, and is adaptable across items that may exhibit widely-varying characteristics. A multi-scale approach enables information to be shared across items with related patterns over time in order to improve prediction, while maintaining the scalability to many items. A motivating case study in many-item, multi-period, multi-step-ahead supermarket sales forecasting provides examples that demonstrate an improved forecast accuracy on multiple metrics, and illustrates the benefits of full probabilistic models for forecast accuracy evaluation and comparison.     

具有异质性非参数时间趋势的面板数据模型的估计

本文为一类具有异质性非参数时间趋势的面板数据模型提出了一种简单估计方法。基于局部多项式回归的思想,首先去除数据中的时间趋势成分,然后由最小二乘法来估计公共系数,同时得到时间趋势函数的非参数估计。在一些正则条件下,研究了这些估计量的渐近性质,即在时间维度T和横截面维度n同时趋向无穷时,建立了各个估计量的渐近相合性和渐近正态性。最后通过蒙特卡洛模拟,考查了这种估计方法的有限样本性质。     

Semiparametric estimation of consumer demand systems in real expenditure

Microdata concerning consumer demand typically show considerable variation in real expenditures, but very little variation in prices. We propose a semiparametric strategy for the consumer demand problem in which expenditure share equations are estimated nonparametrically in the real expenditure direction and estimated parametrically (with fixed or varying coefficients) in price directions. In our model, Engel curves are unrestricted: demands may have any rank. Because the demand model is derived from a cost function, it may be restricted to satisfy integrability and used for consumer surplus calculations. Since real expenditure is unobserved, but rather estimated under the model, we face a semiparametric model with a nonparametrically generated regressor. We show efficient convergence rates for parametric and nonparametric components. We illustrate the feasibility of our proposed strategy using Canadian expenditure and price data: Engel curves display curvature which cannot be encompassed by standard parametric models. We also find that the rationality restriction of Slutsky symmetry is rejected in the fixed‐coefficients model, but not in the varying‐coefficients model. Copyright © 2009 John Wiley & Sons, Ltd.     

Product-Line Length as a Competitive Tool

The increasing number of consumer goods and services offered in recent years suggests that product-line extensions have become a favored strategy of product managers. A larger assortment, it is often argued, keeps customers loyal and allows firms to charge higher prices. There is disagreement, however, about the extent to which a longer product line translates into higher profits. We develop an econometric model derived from a game-theoretic perspective that explicitly considers firms' use of product-line length as a competitive tool. On the demand side, we analytically establish the link between consumer choice and the length of the product line. Based on our derivations, we include a measure of line length in the utility function to investigate consumer preference for variety using a brand-level discrete-choice model. The supply side is characterized by price and line length competition between oligopolistic firms. For the empirical analysis we use market-level data for the yogurt category. We find that there are decreasing returns to product-line length. Based on a series of "what-if" experiments, we derive recommendations for effective product line decisions in a competitive environment.     

A rational rank four demand system

Past parametric tests of demand system rank employed polynomial Engel curve systems. However, by Gorman's ( 1981 ) theorem, the maximum possible rank of a utility‐derived polynomial demand system is three. The present paper proposes a class of demand systems that are utility derived, are close to polynomial, and have rank four. These systems nest rational polynomial demands, and so can be used to test ranks up to four. These systems are suitable for applications where high rank is likely, such as demand systems involving a large number of goods. A test of rank using this new class of systems is applied to UK consumer demand data. Copyright © 2002 John Wiley & Sons, Ltd.     

SMOOTH QUANTILE‐BASED MODELING OF BRAND SALES,PRICE AND PROMOTIONAL EFFECTS FROM RETAIL SCANNER PANELS

Semiparametric quantile regression is employed to flexibly estimate sales response for frequently purchased consumer goods. Using retail store‐level data, we compare the performance of models with and without monotonic smoothing for fit and prediction accuracy. We find that (a) flexible models with monotonicity constraints imposed on price effects dominate both in‐sample and out‐of‐sample comparisons while being robust even at the boundaries of the price distribution when data is sparse; (b) quantile‐based confidence intervals are much more accurate compared to least‐squares‐based intervals; (c) specifications reflecting that managers may not have exact knowledge about future competitive pricing perform extremely well. Copyright © 2013 John Wiley & Sons, Ltd.     

面向售后服务的汽车备品需求预测研究

根据面向售后服务的汽车备品需求特点的差异,本文将其分为专用配件和通用配件并分别选用不同的预测模型.对专用配件,采用基于时间序列相关的线性回归模型,并运用加权最小二乘法（WLS）估计参数.对通用配件,选用GM（1,1）模型进行需求预测.