Insights from Anticipatory Prices

Contemporaneous observations on expected supply and on prices of post‐harvest futures contracts for corn are used to estimate expected demand relationships. These equations are used to estimate the prices of the post‐harvest contracts based on new supply estimates. Each estimate can be compared with a corresponding futures price, i.e. the market forecast. The differences help discern the market expectations about the expected demand for the new crop relative to historical experience, which can help support outlook analyses. We find that in recent years, a 100 million bushel change in the expected supply of corn results in about a 6 cent per bushel negative change in the price of December corn. The discussion also deepens understanding of the term ‘anticipatory prices’ as defined by Holbrook Working in his 1958 work.     

Role of delivery options in basis convergence

The corn futures contract, traded on the Chicago Board of Trade, provides sellers with delivery options about the timing of delivery, the location of delivery, and the grade to be delivered. These options presumably have values that can vary from one delivery month to the next. The joint values of the timing and location options are estimated for each delivery month for the years 1989 through 1997. These estimates are then used in regression models to determine the degree to which they influence basis variability on the first day of the maturity month. Econometric models are also developed to see if the estimated implicit options values are useful in improving the forecasts of basis convergence over the 2‐month period prior to maturity. The results suggested that variation in the delivery options values in the corn futures contract does indeed help explain basis variability on the first day of maturity. An option‐value variable, based on estimated values two months prior to maturity, resulted in occasional, small improvements (from a statistical point of view) in the precision of forecasts. The existence of delivery options increases basis variability at maturity, but it is difficult to use this information to improve forecasts of basis convergence. One limitation of the analysis is that the Chicago cash market had few transactions per day during the sample period, and hence the reported spot prices may be inadequate for making high‐quality estimates of the options values. © 2002 Wiley Periodicals, Inc. Jrl Fut Mark 22:783–809, 2002     

有机—常规农业中作物产量差距分析

有机农业能否生产足够的粮食以保障世界粮食安全,是科学家们历来针对有机农业对未来农业贡献争论的焦点,而在这场争论中有机农业与常规农业的产量比较又是讨论的中心点。为此,文章根据已发表研究成果,编制和分析了一个包含362个有机—常规作物产量比较资料的大型数据库。结果表明,单品种有机作物平均产量为常规作物产量的80%,差别是显著的(标准差为21%)。数据库中有机作物产量因作物类型与种植地区的差异而存在显著差别。分析结果为文章的假设提供了一些支持,即当常规作物产量增加时,有机—常规作物产量差距也增大,但这种关系不甚明显。这一假设背后的基本原理是,当常规作物产量很高,且相对接近潜在产量或水分限制产量时,营养胁迫就成为限制产量进一步提升的因子,因为每个潜在产量或水分限制产量的定义中都有低病虫害或病虫害得到良好控制的限定条件,但这些限定条件在有机农业中难以实现。文章通过有机—常规农业方面文献对研究结果进行了讨论,并细致阐述了研究问题以期获取创新性理论观点。文章观点基于作物在田间小环境水平,因有机农业系统在保持养分有效性面临一定挑战,如应用在作物轮作、农场及大区域等更高级系统水平中常规农业与有机农业平均产量差距可能大于20%。值得特别注意的是豆类作物在轮作、农场、大区域等农业系统中的作用,与在农场、大区域水平下有机肥获取的可能性。因此,未来研究工作应集中评估高级系统中(例如农场、大区域及全球系统水平)的两种农业类型的相对产量,并且应特别注意在这种情况下有机与常规农业中养分的有效性。