Endogeneity in quantile regression models: A control function approach

This paper considers a linear triangular simultaneous equations model with conditional quantile restrictions. The paper adjusts for endogeneity by adopting a control function approach and presents a simple two-step estimator that exploits the partially linear structure of the model. The first step consists of estimation of the residuals of the reduced-form equation for the endogenous explanatory variable. The second step is series estimation of the primary equation with the reduced-form residual included nonparametrically as an additional explanatory variable. This paper imposes no functional form restrictions on the stochastic relationship between the reduced-form residual and the disturbance term in the primary equation conditional on observable explanatory variables. The paper presents regularity conditions for consistency and asymptotic normality of the two-step estimator. In addition, the paper provides some discussions on related estimation methods in the literature.     

国土资源标准化战略的保障体系建设浅析

本文阐述了构建国土资源标准化战略保障体系的目标与原则,详细分析、阐释了国土资源标准化战略保障体系的构成要素,并提出了国土资源标准化战略保障体系需要重点建设的几个方面。     

A Note on Minimax Mixture of Distributions Free Procedure for Inventory Model with Variable Lead Time

In recent papers, Moon and Choi (1998) and Hariga and Ben-Daya (1999)considered a continuous review inventory model with a mixture of backordersand lost sales in which the lead time, the order quantity, and the reorder pointare decision variables was studied. Moreover, they also develop a minimaxdistribution free procedure for the problem. While the demands of differentcustomers are not identical in the lead time, then we can't only use a singledistribution (such as Moon & Choi (1998) and Hariga & Ben-Daya (1999))to describe the demand of the lead time. Hence, we correct and extend the modelof Moon and Choi (1998) and Hariga and Ben-Daya (1999) by considering thelead time demand with the mixture of distributions. In addition, we also applythe minimax mixture of distributions free approach to the model by simultaneouslyoptimizing the order quantity, the reorder point, and the lead time to devise a practical procedure which can be used without specific information on demand distribution.     

基于ERP和TOC的生产物流系统研究

本文通过研究ERP和TOC相结合的生产物流系统的功能，构建了系统的功能模型，给出了模型中生产网络实现的数据模型．最后构建了二者相结告的生产物流系统的总体结构模型。     

事项会计理论:中国研究现状述评

事项会计理论首先由美国学者Sorter于上个世纪六十年代末年提出的,其目的是对传统会计进行彻底的改造。本文首先回顾了国内对这一领域的研究成果,然后做简要评价与展望,以期引起我国会计理论界对这一新领域的更多关注。     

Improving perishable product inventory management using goal programming

The multiple objectives of perishable product inventory management are examined in this paper. These objectives include: (1) satisfying demand by carrying sufficient inventories, (2) holding down inventory carrying costs, (3) keeping the amount of product spoilage (outdating) at an acceptable level, and (4) maintaining quality by using the product while it is still fresh, and (5) keeping the cost of rotation low. Some of the above objectives are in conflict. Thus, certain redistribution policies may help attain one or more of these objectives to a greater extent. Redistribution involves the transfer of the product from outlets where demand is low to outlets where demand is high. A goal programming model for solving redistribution problems is presented. An example is provided and sensitivity analysis is performed in order to determine when redistribution is advantageous. Applicability of the model is discussed.     

Who Gains from the Demographic Dividend? Forecasting Income by Age

Changes in the population age structure are known to influence the total income per person, but little is known about whether the changes are equally shared across the population or are concentrated on particular age groups and/or birth cohorts. The answer to this question has potentially important implications for income inequality, human capital investment, and fertility decision-making. We propose a new model of intergenerational transfers which distinguishes between the effects of changes in population structure and the effects of changes in family age structure. Using age-specific data from annual income and expenditure surveys of Taiwan between 1978 and 1998, we show that changes in age structure have had a very favorable effect on Taiwan's income growth. The gains are not equally shared by all age groups, however. Children and young adults have benefited the most, while the elderly have benefited the least. The population and family age structures have independent effects on per capita income; the effect of the population age structure is most important. Generational differences in per capita income are closely related to intergenerational differences in earnings, suggesting only a weak form of altruism. Finally, we predict that, on average, population aging will adversely influence the per capita income growth in Taiwan in the coming decades.     

山东省水土流失经济损失与生态价值损失评估

介绍了山东省水土流失现状，分析其危害，重点探讨了水土流失经济损失和生态价值损失的计算方法，建立经济损失计算模型，提出水土流失生态一经济面积边际比的概念，计算山东省县域边际损失比，并对其进行区域分布规律分析。     

Further development and sustainable utilization mode of grassland tourism resources: a case study of Inner Mongolia Autonomous Region, China

Tourism resources are important foundation for the development of tourism industry. Grassland is not only a kind of important resource but also a great attraction to visitors. Therefore, the integrated development and sustainable utilization of grassland tourism resources are of great significance. This paper, based on the analysis of literatures and the current problems existing in grassland tourism, summarizes the speciality of grassland tourism development, deals with the problem of speciality, and raises the modes of regional development, product development and management. This paper takes Inner Mongolia, the famous grassland tourism destination as example and carries out empirical research. Based on the status quo of grassland tourism resources in Inner Mongolia, this study analyzes the character- istics of grassland tourism resources, the necessity and feasibility of integrated development, then proposes the following suggestions: idea for development, mode of development, regional cooperation, tourism products development, espe- cially the three modes of development based on the resources conditions - the mode of relying on market, the mode of combination aggregation and the mode of relying on quality.