国内外关于农机需求的理论与实证研究综述

本文从理论和实证研究两个角度回顾了国内外关于农机需求研究的重点文献，归纳了宏观和微观农机需求研究的共同理论基础，探讨了国内外对农机需求研究的进展，最后指出：农机需求的微观研究是目前国内农机需求研究的空白领域和值得进一步研究的、具有理论创新意义的发展方向。     

IntraLATA long-distance demand: carrier choice, usage demand and price elasticities

Competition in the long-distance market in the US continues to intensify; the 1996 Telecommunications Act has led to increased competition in long-distance telephony especially as the Regional Bell Operating Companies have begun to gain entry to long-haul, long-distance markets. In order to better understand the implications of having increased service offerings, models of how customers choose between carriers (and the impact of this choice on subsequent usage) will be useful. We develop the first publicly available models that simultaneously estimate choice and usage for intraLATA long-distance in the US. Utilizing a generalized Tobit model, the price responsiveness of usage and carrier choice are estimated. The results are generally consistent with expectations both in terms of theory and of practical experience in the industry.     

峰荷需求、资本配置效率与中国网络型基础产业投融资机制改革——对阿弗奇-约翰逊模型的一个扩展

阿弗奇—约翰逊模型(A—J模型)表明规制对象具有过度使用资本倾向,相应的实证检验中同时存在肯定和否定的结果,但基本的A—J模型、已有扩展和实证检验都忽略了受规制行业的峰荷需求特征。本文从基本的A—J模型出发,假定生产要素单位使用成本与规制机构所认可的单位核算成本不同,考察了峰荷需求特征下受规制网络型基础产业的投资行为,提供了资本配置效率的衡量标准。本文的基本结论在于,峰荷需求条件下受规制企业不一定投资过多,这也解释了为何A—J效应的实证检验存在相互矛盾的结果。     

中国寿险需求实证分析

本文对国内外的寿险需求分析研究进行了简单综述，在此基础上抽取全目30省市1998—2003年的数据．采取面板数据模型就收入、通货膨胀、社会保障、银行利率、死亡率等寿险需求影响因素与保费收入相关性作了Granger因果性检验分析。     

The Nested PIGLOG Model: An Application to U.S. Food Demand

A new demand system is introduced, the Nested PIGLOG model, nesting thirteen other demand systems including five that are also new. This new model and its nested special cases are applied to models of U.S. food demand that include food-at-home (FAH), food-away-from-home (FAFH), and alcoholic beverages. Although nested tests and out-of-sample forecasting performance favor generalizing models to a certain degree, statistically insignificant improvements to in-sample-fit and even poorer out-of-sample forecast accuracy undermine further generalizations. Based on a subset of preferred models, FAFH is found to be price and income elastic compared to FAH which is price and income inelastic.     

Impacts of Declining U.S. Retail Beef Demand on Farm-Level Beef Prices and Production

A systems model was estimated to determine the effects of declining U.S. retail beef demand on farm-level beef prices and production. Retail beef demand declined by nearly 66% from 1976 to 1999. Results indicate autonomous shifts in retail demand significantly impacted farm-level demands and production. Based on equilibrium multipliers, the 1976–99 reduction in beef demand decreased real slaughter cattle prices and production by 32.1% and 11.2%, respectively. Real feeder cattle prices and production decreased by 8.0% and 22.6%, respectively. Combining the decreases in farm prices and production, slaughter and feeder cattle producers experienced a real revenue reduction of $13.3 billion (61%) due to the long-term decline in demand.     

Diffusion of Products with Limited Supply and Known Expiration Date

In this paper, we provide a model for diffusion of products, which are available in limited quantity until a known expiration date, after which the unsold products have no value. We consider the case of a performing arts company. The model development is built on the foundation of classical product diffusion model by Bass (1969) and the psychological effect known as the scarcity principle (Cialdini, 1985). Our empirical analysis results show that the proposed model can provide significant improvement in prediction of the products characterized by the scarcity effect.     

Demand‐side housing policy in Costa Rica: a response to the housing deficit

The purpose of this study was to establish what the housing needs of Costa Rica are and to assess what policies have been implemented to respond to their housing deficit. In order to answer these questions, a combined methodology consisting of primary and secondary data was used. Using open‐ended questions and a topic schedule, face‐to‐face interviews with Costa Rican housing authorities were conducted at the interviewee's work place in Costa Rica in May 2003. The most recent secondary data available in the country was used to compute the housing deficit and to study the effects of demographics on current housing needs. Sources of the secondary data were the Costa Rica Ministry of Housing and Human Settlements, and the National Institute of Statistics and Census. The Costa Rican government has made great progress in reforming the housing finance system in order to meet the housing demand of its citizens. In 2002, Costa Rica had a 75.6% home ownership rate. Yet, even in light of the housing system's current success, many social, economic and political barriers threaten to undermine its accomplishments and the peoples’ ability to obtain safe and affordable housing. The paper considers the strengths and weaknesses of the current housing finance system as well as the government strategies for addressing difficulties.     

A note on the decomposition (at a point) of aggregate excess demand on the Grassmannian

This paper analyzes the properties of aggregate excess demand functions for economies with an arbitrary finite set of N commodities where agents face trading restrictions of a general, abstract form: their budget set is defined by K-dimensional planes in ^N. It is shown that, if there are at least K agents in the economy, the only general property satisfied by the value of aggregate excess demand and its derivative, at any arbitrary point, is Walras Law. The result is established by considering an economy where agents' preferences are of a ‘generalized Leontief' type.     

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.