改革开放以来我国历次粮食供求失衡的回顾与启示

本文通过对改革开放以来历次重大粮食供求失衡状况的回顾，得出若干重要启示。即20世纪90年代以来，结构问题已经超越总量问题，成为影响我国粮食供求平衡的主要问题；稻谷、粮食主销区和口粮分别是导致我国粮食供求失衡的先导性和敏感性品种、敏感性地区、敏感性用途；品质结构对于粮食供求平衡的影响不断加深，历次粮食供求失衡都与宏观经济环境和经济周期波动有密切关系；农业政策的调整对于粮食供求失衡现象的形成和发展，发挥着重要影响；促进粮食及其主要品种供求平衡的政策调整，不仅要重视粮食市场供给与需求在数量和结构方面的协调、粮食综合生产能力与消费需求能力的协调，更要重视粮食综合供给能力与消费需求能力的协调。     

Impact of hybrid rice on input demand and productivity

This paper uses farm-level data collected from a sample of 500 households in Hunan province, China, to analyze the impact of hybrid rice on input demand and productivity. Based on regression analyses, it is found that, compared with conventional modern varieties, hybrid rice uses about 4% less labor inputs, 2% less draft animal services, and 6% more chemical fertilizers. The lesser requirements for labor and draft animal services probably arise from hybrid rice's lower seeding rate. Due to heterosis and high seed costs, the use of F₁ seed is economized to about one-third to one-fourth that of conventional varieties. Therefore, less labor and animal power is needed for seed-bed preparation and transplanting. It is also found that, given the same level of inputs, the yield advantage of hybrid rice over the conventional modern varieties is about 19%. Because of the productivity potential, hybrid rice is a candidate for the second-generation “Green Revolution” in other parts of Asia.     

Cointegration in China's log import demand: Price endogeneity and structural change

The monthly data of China's log import from January 2000 to December 2013 are used to estimate the import demand elasticities, with the consideration of possible price endogeneity due to China's large share of the international log market, and structural break caused by global financial crisis in 2008. To address the possible structural break, cointegration tests allowing for a deterministic shift in the level of the variables are employed, and a two-stage estimation with top-down sequential elimination algorithm is performed on the restricted subset VECM. The results demonstrate that there exists a long-run cointegration relationship between China's log import and the explanatory variables. The import elasticities of macroeconomic development and import price are around 0.76 and −0.81, respectively. Other things being equal, the structural break would induce a 29.6% decline in China's log import. All the above parameters are significant at the 1% risk level. Furthermore, the contribution decomposition analysis suggests that China's macroeconomic development plays a dominant role in determining its log import, which implies that China's log import would not increase as quickly as before, given that its economy is shifting into the “New Normal State”. This conjecture is supported by our simulations, which indicate that, by 2020, the growth rate of China's log import will be lower than it has been in the past and the import volume would be approximately 1.1–1.6 times greater compared to imports in 2013.     

Elasticity of demand for Australian cotton in Japan

Although a relatively small producer, Australia exports more than 90 per cent of its cotton production, making it the world's third largest cotton exporter in recent years. This means that export performance plays a major role in determining the profitability of the Australian cotton industry. The primary aim of this study was to determine the competitive position of Australian cotton in the Japanese market, based on the original non-linear Almost Ideal Demand System model using data from 1972 to 1998. The main findings are that the USA had a relatively strong market position and that Australia needs to improve its cost competitiveness and quality image to advance its market standing.     

溧水县水资源供需分析

针对溧水县水资源特点,分析水资源现状。结合节水型社会建设的要求,采用相应的定额,分析预测了各行业需水量和供水量,分析不同平衡分析方案的缺水度。分析表明,在一次平衡方案下,溧水县近期和远期缺水度均大于30%,处于严重缺水状态。在二次平衡方案下,可以有效地解决缺水问题。     

海南省水资源供需分析

阐述海南省水资源的特征及变化趋势,并针对水资源供需中存在水资源开发利用率低,用水效率不高,水环境污染和水资源供需矛盾大等问题,提出保障水资源供需的战略措施,即建立新型水资源价值体系、水资源供需保障体系、水资源供需集团化与规模化经营体系和水资源安全保障体系等。     

农业专业合作社的融资供求衔接问题研究

农业专业合作社融资具有一般企业所不具有的特殊性。论文从理论角度分析了农业合作社融资次序的选择,认为通过正规金融实现合作社融资供求衔接的有效途径。在供求不平衡,传统信贷供给无法满足合作社融资需求的状况下,探索了“公司＋合作社＋农户”、“农业龙头企业＋担保公司＋合作社＋农户”、“政府＋农业生产基地＋农业企业＋合作社＋农户”三种农业产业链融资模式,并分析了其主要特点、优势以及主要风险,为合作社融资提供了新思路。     

河北省水产品供给与需求预测分析

论文在河北省水产品供给与需求分析基础上,选择时间序列数据,运用线性回归模型和灰色预测模型对2010～2014年的水产品市场供给与需求趋势进行了预测。预测结果显示,"十二五"期间河北省水产品市场的供求状况将由供给大于需求向需求大于供给转变。随着城乡居民消费和水产品加工消费的增加,2012年将达到供需均衡,2013年后将出现需求大于供给的形势。根据对未来水产品市场的均衡分析,提出应选择政、产、学、研相结合的开发模式,实现科技兴渔和产业化发展;提高水产品加工效率,提升产业附加值;大力加强渔业流通和服务业等渔业经济发展等建议。     

我国农业保险供求主体有效合作模式的思考

近年来,我国农业保险快速发展,但仍存在着承保额不足、基础服务不完善、经营区域划分不合理等问题。本文基于农业保险合作模式的效用分析,认为政府主导下商业保险公司经营模式是比较符合我国国情,能够充分调动政府、企业、农民三方积极性的有效的农业保险组织发展模式。为了保证这一合作模式的落实,本文从完善农业保险的激励机制、保障机制和监督机制等方面提出了对策建议。     

Rural-urban gradient analysis of ecosystem services supply and demand dynamics

Urban regions are important places of ecosystem service demands and, at the same time, are the primary source of global environmental impacts. Although there is broad agreement on the importance of incorporating the concept of ecosystem services into policy strategies and decision-making, the lack of a standardized approach to quantifying ecosystem services at the landscape scale has hindered progress in this direction. Moreover, tradeoffs between ecosystem services and the supply/demand ratio of ecosystem services in urban landscapes have rarely been investigated. In our paper, we present a method to quantify and map the supply and demand of three essential provisioning services - energy, food, and water - along the rural-urban gradient of the eastern German region Leipzig-Halle. This urban region has experienced significant socio-economic dynamics and land use changes since the German reunification in 1990. The results show that both the demand and the supply of ecosystem services changed considerably during the time span under consideration (1990-2007). We identified an increasing supply/demand ratio of food and water but a decreasing supply/demand ratio of energy. In addition, the pattern of ecosystem demands shows a levelling of rural-urban gradients, reflecting profound modifications of traditional rural-urban relationships. The changes of ecosystem service supply gradients are determined more by land use intensity, such as the intensification of agricultural production, than by land cover changes such as urban sprawl. The comparison of supply/demand ratios and rural-urban patterns of ecosystem services can help decision-makers in landscape management in striving for a sustainable balance between resource supply and demand.     

市场经济条件下我省粮食供求状况及对策

2004年以来,国务院决定按照"放开购销市场,直接补贴粮农"的思路,全面放开粮食购销市场和价格,充分发挥市场机制在配置粮食资源中的基础性作用,实现了粮食购销市场化和市场主体多元化.     

日本紫菜市场的供需构造及产业发展现状分析

日本是世界主要紫菜消费国、生产国。同时,也是中国紫菜出口的主要贸易国之一。其紫菜养殖业在经历了80年代繁荣期后,从90年代开始产业发展停滞,紫菜需求市场萎缩。1996年后伴随着中韩两国紫菜产品的市场介入,供需构造发生改变。由于同时面临不利需求条件、双重贸易壁垒以及来自韩日两国的竞争压力,中国紫菜对日出口受阻。但是,2011年后受"3.11大地震"影响,日本国内供给出现短缺,一定时期内将利好中国紫菜出口。对此,中国应确保安全稳定的加工原料供应、降低生产和交易成本,同时利用提高产品质量、细分市场、树立品牌意识等措施增强非价格竞争力,扩大对日出口。     

基于AHP方法的贵州省水资源供需评价与分析

贵州省喀斯特地貌发育强烈,山高水低,水资源开发利用困难,直接影响到其水资源的供需平衡。选取水资源供需状况的4个准则层,分16个指标,通过AHP方法对各指标进行赋权,对贵州省各地区水资源供需状况进行了综合评价。得出贵州省虽然水资源总量比较丰富,但由于喀斯特地貌的发育,水资源供需总体上处于较低水平,其中黔东南喀斯特地貌比例最低,水资源供需水平最高,毕节地区最低。喀斯特地貌的发育限制了地区水资源供需水平的提高,但经济技术水平的发展能大大减弱喀斯特地貌的影响。不合理的水资源开发利用极易造成喀斯特地貌生态环境的破坏,加剧喀斯特地貌因素对水资源供需水平的限制。     

区域水资源供需的系统动力学仿真

以广东省北江下游影响区为研究范围，基于系统动力学的理论和方法，按照科学发展观的要求，应用系统分析、可持续发展的思路，在系统分析区域水资源供需系统各要素之间及其与人口、经济、社会、生态环境等发展之间互动影响关系的基础上，建立区域水资源供需的系统动力学模型，并进行了动态仿真模拟，认为GDP增长受到水资源不足的制约，因此，在追求经济效益的同时，必须考虑到水资源的可持续利用，而不是“掠夺式”利用，注重GDP增长速度与环境保护的协调发展。     

Effects of direct payments on rice income variability in Japan*

The effects of direct payments on rice income variability in Japan are analysed based on a balanced panel dataset of Japanese rice farms for 2012–2016. Firstly, the contribution of income components to rice income variability and the effects of a direct payment reduction are discussed by applying variance decomposition. Secondly, robust regression techniques are used to measure the correlation between direct payments and rice income variability. The originality of this paper is that it disaggregates the effects of payments using a regression analysis of the effects of direct payments on income variability for Japan. This contrasts with the existing literature on this topic, which has largely focused on European Union countries. This paper discusses to what degree the reduction in direct payments increases income variability. The results reveal that direct payments decrease Japanese rice income variability. Indeed, after controlling for various farm characteristics, we find a negative relationship between the amount of direct payments linked to rice production and rice income variability. Finally, the results suggest that reducing direct payments when the rice price is falling would increase rice income variability.     

Why projections on China’s future food supply and demand differ

This article analyses the macroeconomic assumptions, demand and supply parameters, and structures of the models used in projecting China's future food supply, demand and trade. Projections vary greatly, from China being self-sufficient in grain to being a net importer of 369 million metric tons of grain in 2030. The differences stem mainly from the approaches chosen to model China's grain production and, in particular, the combined effects of land decline and yield growth. The article also points out improvements needed in future work on modelling China's grain economy, which include accounting for the links between agriculture and other sectors, technical change in the livestock industry and infrastructure constraints on grain imports.