Pre-Harvest Price Expectations for Corn: The Information Content of USDA Reports and New Crop Futures

This article examines the puzzle of why futures prices continue to react to USDA crop reports despite the fact that reports appear to be no longer "newsworthy," that is, provide no better production estimates than private forecasts. The information value of reports is measured in terms of their influence on rational agents' harvest-time corn price expectations, which are uncovered using a Hamilton-type modeling approach. Results show that reports are still "newsworthy," as they would contribute to agents' price expectations if released a day early. Thus futures price reactions, which closely reflect price expectations, are rational and consistent with efficient markets hypothesis.     

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.     

Estimating the Impact of Transgenic Bt Cotton on West and Central Africa: A General Equilibrium Approach

West and Central Africa (WCA)’s cotton sector is experiencing rising production costs and lower yields, reversing decades of growth. Declining input use, soil fertility and inefficient chemical pest controls are contributing factors. We evaluate the potential impact of Bt cotton on WCA using a multiregion general equilibrium model and multicountry estimates of Bt-induced productivity. We find that Bt cotton raises growers’ returns, land value and welfare. Released labor from cotton is shifted to food crops hence reducing labor shortage constraints. Overall, results indicate that potential gross benefits from Bt cotton are substantial for WCA cotton sector, and that the economic costs of nonadoption are equally significant.     

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation

Use of biofuels diminishes fossil fuelcombustion thereby also reducing net greenhousegas emissions. However, subsidies are neededto make agricultural biofuel productioneconomically feasible. To explore the economicpotential of biofuels in a greenhouse gasmitigation market, we incorporate data onproduction and biofuel processing for thedesignated energy crops switchgrass, hybridpoplar, and willow in an U.S. AgriculturalSector Model along with data on traditionalcrop-livestock production and processing, andafforestation of cropland. Net emissioncoefficients on all included agriculturalpractices are estimated through crop growthsimulation models or taken from the literature. Potential emission mitigation policies ormarkets are simulated via hypothetical carbonprices. At each carbon price level, theAgricultural Sector Model computes the newmarket equilibrium, revealing agriculturalcommodity prices, regionally specificproduction, input use, and welfare levels,environmental impacts, and adoption ofalternative management practices such asbiofuel production. Results indicate no rolefor biofuels below carbon prices of $40 perton of carbon equivalent. At these incentivelevels, emission reductions via reduced soiltillage and afforestation are more costefficient. For carbon prices above $70,biofuels dominate all other agriculturalmitigation strategies.     

贵州省县域经济的综合评价

运用因子分析法可对贵州省2003年县域经济的综合指标进行评价.其过程是:通过SPSS统计软件进行计算和分析,以斜交旋转后的综合因子得分作为县域经济综合实力的度量,给出贵州省2003年各区县的综合实力排序以及等级划分情况并做出相应的评价.     

渐开线圆柱齿轮的形位误差探讨

从误差角度分析，综述ＧＢ１００９５－８８《渐开线圆柱齿轮精度》误差的表达方法。     

Could the Faustmann model have an interior minimum solution?

The growth of an even-aged stand usually follows a S-shaped pattern, implying that the growth function is convex when stand age is low and concave when stand age is high. Given such a growth function, the Faustmann model could in theory have multiple optima and hence an interior local minimum solution. To ensure that the rotation age at which the first derivative of the land expectation value equals zero is a maximum, it is often assumed that the growth function is concave in stand age. Yet there is no convincing argument for excluding the possibility of conducting the final harvest before the growth function changes to concave. We argue that under normal circumstances the Faustmann model does not have any interior minimum. It is neither necessary nor proper to assume that the growth function is concave in the vicinity of the optimal rotation age. When the interest rate is high, the optimal rotation may lie in the interval on which the growth function is convex, i.e. before volume or value growth culminates.     

生物质能源可利用潜力评价*——以黑龙江省重点国有林区为例

[目的]生物质能源具有污染少、可再生等特点,合理地对其开发利用是黑龙江省重点国有林区经济转型发展的一种探索。通过对黑龙江省重点国有林区生物质能源资源量的计算,明确了生物质能源的可利用潜力及变化趋势,以期为其产业发展的政策制定提供理论参考。[方法]文章利用自下而上估算法,以林木生物质的资源量和农作物秸秆的产量为原始数据,对2005—2015年黑龙江省重点国有林区生物质能源可利用潜力进行评价。[结果](1)研究期间,黑龙江省重点国有林区林木生物质资源可利用潜力小幅下降,农作物秸秆资源可利用潜力稳步上升。(2)林木生物质资源中,商品林采伐剩余物可利用潜力骤降,森林抚育剩余物可利用潜力增加;农作物秸秆资源中,粮食作物秸秆可利用潜力逐年上升。(3)黑龙江省重点国有林区生物质能源可利用潜力随着国家"天保工程"和"重点国有林区全面禁止天然林商业性采伐"政策的实施而发生变化。[结论]黑龙江省重点国有林区生物质能源丰富,可利用潜力较大,其中农作物秸秆资源可利用潜力增速较快。     

Official rotation and corporate innovation: Evidence from the governor rotation

Rotation is a practice whereby officials are regularly moved between equally ranked positions. Focusing on governor rotation, this paper examines the effect of official rotation on corporate innovation in China. First, we find that official rotation significantly promotes corporate innovation, including enterprises’ innovation investment, quantity, and quality. Second, we find that the effect of official rotation on corporate innovation varies because of official and regional heterogeneity. Officials rotating from other provinces significantly stimulate corporate innovation, but officials rotating from the central government have an insignificant influence on corporate innovation. In addition, officials rotating to non-eastern regions significantly enhance corporate innovation, while officials rotating to eastern regions have a negligible impact on corporate innovation. We further examine the driving mechanism behind the effect of official rotation on corporate innovation and find that officials rotating from eastern regions to non-eastern regions can significantly promote corporate innovation, but officials rotating from non-eastern regions to eastern regions do not boost corporate innovation. These findings imply that the different effects of official rotation on corporate innovation are due to the official experience effect. We also find that official rotation can promote corporate innovation through reducing corporate charitable donations and increasing corporate innovation subsidies. In a supplementary analysis, we find that GDP-oriented performance appraisal pressure weakens the effect of official rotation on corporate innovation. The lower the pressure on officials regarding their performance, the more significant the effect of official rotation on corporate innovation. In addition, official rotation can significantly promote the development of the regional economy and improve the GDP growth rate via corporate innovation, which is a micro-level economic growth effect of official rotation. Overall, our findings further verify the economic effect of official rotation and extend our understanding of the influencing factors of corporate innovation from the perspective of the official governance system. Our findings also have clear policy implications for how the government can improve the official governance model to promote corporate innovation during the transition period of the national innovation system.