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。     

领导干部在农业结构调整中应强化十种意识

新阶段的农业结构调整,必须适应变化了的新形势.为此,要进一步深化对农业结构调整的认识,牢固树立大农业意识、市场意识、规则意识、品牌意识、科技意识、信息意识、产业意识、工业意识、城镇意识和服务意识.     

Domestic Support and Border Measures for Processed Horticultural Products

In horticultural markets, trade barriers often apply to the processed products whereas domestic support applies to farm-produced raw commodities. Here we assess the effects of such trade barriers and domestic support by simulating the effects of policy reform on global processing tomato markets, which are faced with modest processed product tariffs and high domestic support in the European Union (EU). Both protection and EU subsidy drive down world welfare, but we find that reducing import tariffs for tomato products would yield greater effects on markets and larger welfare impacts outside Europe than would reductions in EU domestic support.     

基于引力模型的中美农产品贸易边境效应研究

针对中美两国在农产品贸易上的新变化,应用引力模型的派生模型——边境效应引力模型对中美两国农产品贸易的流量和流向进行理论和实证研究。首先介绍了边境效应引力模型基本模型的推导过程,并引入了调整模型。然后采用1987至2005年其中5年的截面数据进行计算,结果发现:中美农产品贸易的边境效应显著存在,且呈逐年下降趋势;两国之间的农产品贸易边境效应存在流向和区域上的差异;距离的平方并不影响模型的可靠性。     

An empirical investigation of firm public and private knowledge

Many studies examine firm private knowledge, but purport to be generalizable to the totality of firm knowledge, both public and private. This study demonstrates that public and private firm knowledge are empirically separable constructs that have significant and yet different influences on innovative outcomes. The example of product development effectiveness within this study shows that both public and private knowledge are significantly related to product development quality; however, public knowledge is negatively related to quality lapses while private knowledge is positively related to quality lapses. Copyright © 2002 John Wiley & Sons, Ltd.     

Stop and Go Agricultural Policies with a Land Market

This article studies the design of farm policy in the presence of asymmetric information about farmers' productivity, a government objective to insure farmers a minimum "parity" income, an endogenous land rent, and diminishing returns on alternative (nonprogram crop) land uses. In this setting, acreage set asides are never part of an optimal farm policy, although compensated acreage limits are. When there are new farmer entrants who cannot be excluded from farm programs, optimal policy takes the form of a pure voluntary acreage limitation—or "buyout"—program in which high-cost producers participate and low-cost producers do not.     

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.     

Learning across the life cycle: Experimentation and performance among the hollywood studio heads

Guided by notions from the literature on organizational learning, this paper investigates how product line experimentation and organizational performance change across the careers of top managers. Its subjects are the studio heads who ran all the major Hollywood film studios from 1936 to 1965. The study found first, that product line experimentation declines over the course of executive tenures; second, that there is an inverse U‐shaped relationship between top executive tenure and an organization's financial performance; and third, that product line experimentation is more likely to benefit financial performance late in top executives' tenures. These findings are consistent with a three‐stage ‘executive life cycle’. During the early years of their tenures, top managers experiment intensively with their product lines to learn about their business; later on their accumulated knowledge allows them to reduce experimentation and increase performance; finally, in their last years, executives reduce experimentation still further, and performance declines. Copyright © 2001 John Wiley & Sons, Ltd.     

Quality Competition and Social Welfare in Markets with Partial Coverage: New Results*

We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant.     

论建国以来中国共产党的农业生产力发展观

建国以来,党的农业生产力发展观经历了探索、调整和完善的过程。第一代领导集体的农业生产力发展观偏重于农业制度的改革,进行了以集体组织下改革农业技术的实践,因忽视农民积极性和生产力系统的协调性,其实践效果差。第二、三代领导集体改变了党对农业的领导方式,高度重视农民积极性和生产力系统的协同性,形成了包括发挥农民积极性、现代工程和生物技术与传统农业技术相结合、市场农业和尊重自然规律为内容的农业生产力发展观。这是中国当代农业生产力发展的成功经验,也是党对传统农业重视天地人协调经验的继承。