Modeling Conditional Yield Densities

Given the increasing interest in agricultural risk, many have sought improved methods to characterize conditional crop-yield densities. While most have postulated the Beta as a flexible alternative to the Normal, others have chosen nonparametric methods. Unfortunately, yield data tends not to be sufficiently abundant to invalidate many reasonable parametric models. This is problematic because conclusions from economic analyses, which require estimated conditional yield densities, tend not to be invariant to the modeling assumption. We propose a semiparametric estimator that, because of its theoretical properties and our simulation results, enables one to empirically proceed with a higher degree of confidence.     

Stochastic Technology, Risk Preferences, and Adoption of Site-Specific Technologies

A model of farmer decision making is developed to determine the extent to which uncertainties about soil fertility and weather affect the value of site-specific technologies (SSTs) using jointly estimated risk and technology parameters. Uncertainty can lead risk-averse farmers to apply more fertilizers and generate more pollution than in the certainty case. Ignoring uncertainty and risk aversion would overestimate the economic and environmental benefits of SSTs and underestimate the subsidy required to induce adoption. Accounting for uncertainties and risk preferences might explain the low observed adoption rates of SSTs. Improving the accuracy of SSTs would increase the incentives for adoption.     

对《形状和位置公差》新标准的理解和应用

通过对《形状和位置公差》新、旧国际的对比，综述了新、旧标准间的不同之处、便于迅速了解和应用新标准。     

Price rigidities and institutional variations in markets with posted prices

Summary Standard laboratory posted-offer markets respond slowly and incompletely to demand shocks. In these one-sided markets, where sellers control the setting of prices, very little information is transmitted via the process of exchange. For this reason, traders have trouble distinguishing randomness in their own experience from changes in market fundamentals. This paper reports the results of twelve laboratory markets conducted to assess whether some common variants to standard posted-offer rules can correct the adjustment deficiences. Although discounting, multiple postings and excess demand information all improve performance, we find that response remains poor, and efficiencies low.Support for this research was provided by the National Science Foundation (SBR 9319842 and SBR 9320044), and the University of Virginia Bankard Fund. Data are archived at FTP address: fido.econlab.arizona.edu. We wish to thank Charles Plott and Shyam Sunder for useful comments on an earlier draft of this paper. The usual disclaimer applies.     

试论建立和完善农村合作金融管理体制

建立和完善农村合作金融管理体制是我国金融体制改革的重要组成部分。我国农村合作金融虽然有了很大发展 ,但农村合作金融管理体制还存在很多弊端 ,迫切需要建立和完善具有中国特色的农村合作金融管理体制。本文在充分分析问题和弊端的基础上 ,科学地提出了建立新体制的构想 ,对于加强农业的基础地位、促进农村经济发展有着十分重要的意义     

通用ATS实现技术研究

我国武器装备通用ATS(自动测试系统)经历了从引进、仿制到自行研制的过程，但是目前通用ATS总的局面是通用ATS不通用，这种局面主要是由于国内对通用ATS实现技术缺乏统一认识造成的。基于此，本文研究了与开发通用ATS密切相关的标准／规范、硬件配置技术、接口技术、集成测试软件开发环境技术。本文的研究结果适用于所有开发通用ATS的项目。     

China’s Labor Market on Crossroad

I.IntroductionSincethelate1990s,China’slabor market has comeundergreat pressure,asreflected by anincreasing unemployment rate,and adeclining labor force participation rate.The causesofthe severe unemployment are threefold.First,due to the macro-economic downturn andrapid industrial structural change in the late1990s,state-owned enterprises(SOEs),whichlost their comparative advantage and competitiveness,have been unable to fully utilizetheir production capacity,and have become loss-makers.Se…     

湖南农产品如何跨越绿色壁垒

湖南省作为农业大省,农产品的出口受到日益兴起的绿色壁垒的挑战。文章论述了湖南省农产品出口遭遇绿色壁垒的状况及原因,提出了湖南省农产品跨越绿色壁垒的对策。     

不同区位小城镇成长理论与模型--以欠发达地区为例

通过分析和论证不同区位时欠发达地区小城镇成长的影响,并与发达地区小城镇成长的区位条件相比较,揭示了欠发达地区小城镇成长的区位独特性以及区位制约机制,探讨了不同区位条件下小城镇成长的不同模式.