From cultivation to culture: Wheat farming and sex selection in China

Sex selection has been linked to son preference and discrimination against girls in many Asian countries. In this study, we shed light on the shaping role of rice–wheat cropping system to the subsequent gender inequality in China. Using an individual-level dataset compiled from a national scale survey and an archaeology publication, we show regional differences in gender inequality across China: parents show strong gender discrimination against girls in wheat regions. And 15.2 percentage points more parents from wheat regions engage in successful sex selection than those from non-wheat regions. The mechanism analysis reveals that women empowerment matters.     

Cash Marketing Styles and Performance Persistence

Much agricultural economics research has been dedicated to determining the best time for producers to sell their commodities. Unlike this past research, we look at how producers actually sell commodities. The extent to which producers display an active or mechanical marketing style is measured using individual farmer sales. The activeness of a producer's marketing strategy is measured by how much the timing of their strategy varies from year to year. Results show no relationship between activeness and net prices received. Furthermore, the results show no evidence of performance persistence by individual producers.     

Measuring the Volatility of Wheat Futures Prices on the LIFFE

Agricultural prices rose dramatically in 2007 and have subsequently fluctuated at high levels. This paper estimates the volatility of daily wheat futures prices on the Euronext/London International Financial Futures and Options Exchange for 1996–2012 using an exponential generalised autoregressive conditional heteroscedasticity model with a constant (price) elasticity of variance (CEV) and a broken trend. Results show that volatility is highly persistent; there is a structural break in volatility in June 2007 when volatility rose by 10%; subsequently, the wheat futures price has become more volatile; and the CEV is 0.04.     

Price relationships between qualitatively differentiated agricultural products: organic and conventional wheat in Germany

Organic agriculture, which produces commodities that can be qualitatively differentiated from conventional food products, has grown into an important market in many countries. The dynamics of commodity prices in both sectors are partly interdependent, but are also shaped by independent determinants and have rarely been studied. We analyze organic food markets and their interdependencies with conventional markets in the context of wheat markets in Germany, which have been subject to a number of fundamental changes during the last two decades. Based on institutional market characteristics, we suggest a flexible Markov‐switching asymmetric time series model. We find a pronounced temporal sequence of market phases that differ in their asymmetric dynamics and the extent to which the organic price is influenced by the conventional price. Organic wheat prices tend to be increasingly connected to prices of conventional wheat.     

Crop genetic diversity, farm productivity and the management of environmental risk in rainfed agriculture

This paper presents an assessment of the linkages between cropgenetic diversity, farm productivity and risk management. Aflexible moment-based approach is used to analyse the impactof crop genetic diversity on the mean, variance and skewnessof yield. Using farm-level data from Sicily (Italy), econometricevidence shows how crop genetic diversity can increase farmproductivity and reduce risk exposure. The empirical resultsindicate that crop genetic diversity can reduce variance, butonly if pesticide use is low. Furthermore, high diversity levelscan reduce downside risk exposure (e.g. the risk of crop failure).This provides useful insights on the linkages between resilienceand crop genetic diversity.     

产品开发组织超模块化及其对创新的影响——以丰田汽车为案例的研究

本文从产品模块化与组织模块化非对应关系的立论出发,基于对丰田汽车开发系统的典型案例研究,重点探讨了模块化产品开发中超模块组织的性质、成因、结构形态及其在产品创新中的作用。研究发现,模块化产品的开发过程并不一定要采取与之同构的模块化组织形式,相反,以超模块组织来加强开发过程中各任务模块之间的联系,有利于促进整个产品系统的突破性创新。本文将模块化产品开发系统中采用超模块组织形式归结为影响产品系统创新绩效的调节变量,由此深化了对组织模块化结构表现形态及其前因后果的认识。     

安徽省亳州市小麦产业现状与发展策略研究

目的 亳州市位于黄淮麦区,是安徽省小麦种植面积第二大地市,亳州小麦产业化发展对安徽省至关重要,总结亳州小麦产业发展现状,分析其存在的主要问题,为亳州小麦产业化发展提供建议。方法 文章通过对亳州小麦产业和加工企业进行实地调查,委托亳州市农业局和农业科学院组织主题为小麦生产和消费的座谈会,收集小麦种植品种、种植面积以及产量等相关数据,分析小麦产业化发展现状及现存主要问题。结果 亳州市形成以优质强筋小麦、中强筋小麦、中筋小麦为主,弱筋小麦为辅的种植结构,2019年优质专用小麦种植面积占小麦总面积69%。现有规模化面粉企业28家,合计年加工小麦约200万t,消费当地近60%的小麦。小麦产业发展过程中存在“农业合作社规模较小,种植规模和专业技能不足”“订单农业较少,小麦优质不优价”“面粉企业规模较小,下游食品加工企业少”“产业链间的融合不够紧密”等问题。结论 提出“构建大规模小麦加工体系,发挥龙头企业的产业带动作用”“发展农业专业合作组织,实现规模化、标准化、专业化种植”“研发优质品种配套栽培技术,实现良种良法”“打造优质专用小麦生产示范区,培育区域品牌”等策略建议。     

基于地块单元的冬小麦遥感估产方法研究

[目的]以高分时序遥感影像为基础数据源,结合土地承包经营权地块数据,对冬小麦遥感估产方法及其精度进行研究和分析。[方法]文章以河南省兰考县为研究区,采用2019年4―5月份的GF-1C和GF-6 2 m PMS遥感影像提取了研究区冬小麦种植空间分布,并在地块单元控制下对冬小麦种植面积进行了修正和精度验证。其最优提取结果的修正阈值为0.93,地块单元内冬小麦总体分类精度为95.66%,Kappa系数为0.89。利用3月7日至5月20日6期GF-1 WFV遥感影像序列NDVI和RVI与冬小麦种植地块单元数据进行空间统计,得出各冬小麦种植地块单元内NDVI和RVI均值,通过分析冬小麦测产地块单元内均值植被指数与产量间的敏感性,提出一种组合均值植被指数的冬小麦遥感估产模型构建方法,通过交叉验证法对不同的估产线性回归模型进行精度评价。[结果]由4个均值植被指数组合变量的多元线性回归模型为最佳,决定系数为0.922 0,预测误差为40.96 g/m~2,预测精度为93.13%。通过该模型得出兰考县冬小麦平均产量为6 047.25 kg/hm~2,较2017年河南省统计年鉴研究区冬小麦平均单产6 001 kg/hm~2有所提高,土地承包经营权地块内和地块外冬小麦总产量分别为2.76亿kg和4 650万kg。[结论]该方法实现了冬小麦估产结果以像元为单位向以地块单元为单位的转变,解决了模型构建时光谱信息与实测产量间对应问题,为利用国产高分卫星进行县域地块尺度遥感单产精准化估算提供了方法支撑。     

龙头企业、专利投入与农业产业高质量发展研究

[目的]中共十九大报告提出实施乡村振兴战略,对中国粮食产业高质量发展和农业供给侧结构性改革有了进一步要求。小麦作为中国主要粮食作物之一,小麦产业是中国农业产业的代表性产业之一,其发展对中国粮食安全具有重要意义。以小麦产业为例,探究农业科技创新中龙头企业、专利投入与中国小麦产业发展的关系。[方法]文章基于2015—2018年的短面板数据,利用耦合协调度模型测算中国31省(市、自治区)的小麦产质量耦合协调度,解析中国小麦产业耦合协调发展的实际情况,并运用工具变量Tobit方法实证分析中国小麦产质量耦合协调度的影响因素。[结果]中国小麦产质量耦合协调度总体偏低。龙头企业数量、农业基础设施对小麦产质量耦合协调度产生显著的正向影响,地区小麦专利数量在龙头企业对小麦产业的影响中具有正向调节作用。[结论](1)中国小麦产质量耦合协调度总体上还处于较低水平;(2)在小麦产质量耦合协调度回归模型中,粮食播种面积是一个有效的工具变量,它在很大程度上决定了龙头企业选址;(3)小麦专利数量对小麦产质量耦合协调具有直接促进作用,但是这种作用不显著;(4)地区小麦专利的调节效应增强了龙头企业与小麦产质量耦合协调度的影响。     

Market intermediaries,storage and policy reforms

Intermediaries play a crucial role in the functioning of agricultural and food markets in developing countries through linking production, imports and storage with consumption. We analyse how competition in the intermediary sector and alternative forms of intermediaries determine the incentives for storage and market outcomes more generally. We apply this framework to the Egyptian wheat sector as an illustrative case study, a country where food security is a priority, where both forms of intermediaries co-exist and undertake storage but where issues of reforms to the role of intermediaries have been raised. Through stochastic simulation, we analyse two changes in government policy: first, the effects of changing the policy instruments with both types of intermediaries undertaking storage; second, relating to market reforms where the private sector replaces the storage function of the parastatal. These issues have wider significance for addressing the interaction between food security and a wide range of policy reforms including de-regulation of parastatals in developing countries.