Wheat variety yield data: Do commercial and public performance tests provide the same information?

Wheat yields from reported performance test results are of economic importance to wheat producers, since their profits depend on selecting the optimal variety for their location. However, our data shows differences in absolute and relative wheat yields between commercial and public wheat breeding program's performance test data in Kansas. Newly available data are used to test if the difference in yields arose from potential selectivity bias, and to determine the contribution of private and public wheat breeding programs to varietal yield improvement during 2007–2012. Both Heckman selection models and multiple regression showed no statistical evidence of the potential presence of selectivity bias rather, managerial practices, agronomic conditions, field location, and inherent genetic traits of the seed variety were identify as the source of yield differences.     

Modeling farmers’ decisions on tea varieties in Vietnam: a multinomial logit analysis

This article analyzes households’ choice on tea varieties in Vietnam by using a multinomial logit model. The modeling takes into account the issue of unobserved individual heterogeneity and the endogeneity of some explanatory variables (use of chemical and organic fertilizers). The results show that important factors influencing the decision to adopt one type of tea varieties include income, age, household size, farming contract, and use of organic fertilizers, but also membership of professional associations such as the Tea Association and the Farmers Union.     

Business and the limited reconstruction of industrial relations in the UK in the 1970s

Industrial relations were reconstructed in the UK in the 1970s, but only in a limited way. This article examines how business preserved ultimate managerial prerogative in the organisation of the firm and the workplace by constraining the process of reconstruction. The analysis contributes to understanding of business in the 1970s and varieties of capitalism literature on comparative political economy by suggesting that changes in industrial relations were accepted by business only where congruent with corporate strategy. Evidence comes from industrial relations surveys and the Bullock Inquiry on board-level worker participation.     

地勘单位产业发展的战略思考

文章结合湖南省地矿局的实际 ,分析了地勘单位产业发展的必要性 ,指出了目前地勘单位产业发展中存在着工勘业领域过广 ,优势产业不明显 ;多种经营业发展不稳定等问题。指出应努力使基地物业逐渐成为地勘单位经济亮点。认为确定优势产业是地勘单位产业发展的必然选择 ,而做强做大优势产业是地勘单位产业发展的关键。     

小麦价格波动的时间序列分析

粮食价格波动的成因一直是学术界关注的问题。本文通过对1995年1月至2005年12月全国小麦批发市场月度价格序列的分析，表明所观察的小麦价格序列的分布不符合传统线性回归模型关于独立同方差的假设，其特征比较适合使用ARCH族模型来描述。GARCH（1，1）模型的结果显示，由前期价格代表的存粮情况对现期小麦价格影响显著，前期的高价会引发未来小麦市场较大的价格波动；考察期间两次大的粮食市场改革虽然对短期小麦价格有影响，但并未引发剧烈的小麦价格波动。     

Is the variability of world wheat prices increasing?

Estimates are derived of the potential variability of world wheat prices and the sources of this variability. These indicate a sizable increase in the probability of large short-run fluctuations in price. The bulk of this variability is due to fluctuations in the domestic grain production of developing and centrally-planned economies. However, most market participants are unresponsive to short-run changes in world price, and transmit a substantial amount of domestic variability to the world market. The key factor in world price stability is the short-run responsiveness of wheat exports from the USA. It is likely that both the physical and policy factors that have contributed to increased variability will persist.     

初探三峡水库湿地面临的问题及其对策

三峡水库建成后,将成为我国最大的人工湿地,库长约650km,平均水面宽1 500m,具有脆弱性、不稳定性及其多功能性的特征;分析了三峡水库湿地面临的3个问题:水污染现状及新污染问题的预测、泥沙淤积及其发展态势、生物多样性危机及其增多的趋势;提出了保证三峡水库湿地可持续利用的措施:制定三峡湿地地方性保护法、建立国家级湿地自然保护区、加强三峡湿地重要性的宣传教育、提高公众保护意识及搞好长江上游生态恢复重建等。     

改革开放30年来中国票据市场发展历程回顾

该文首先回顾我国票据市场所经历的推广使用、制度建设和快速发展三个阶段,以及1994年以来我国票据市场发展的主要特征;在此基础上文童进一步分析了我国票据市场发展中存在的主要问题,认为我国票据市场的发展还存在信用基础薄弱、市场主体缺位、品种单一、法规滞后、市场分割明显等问题;进而指出我国票据市场的发展可借鉴英国、日本的市场模式,发挥政府引导和市场调节的各自优势,逐步形成一个稳健有序的票据市场,传递中央银行货币政策。