基于三维分形的山东省农户分化及耕地利用异质性分析

研究目的:揭示农户分化的内在机制及其耕地利用异质性,正确引导农户耕地经营行为和可持续利用。研究方法:基于分形理论建立"职业—收入—耕地规模"三维农户分类体系,开展山东省农户耕地利用调研及实证分析。研究结果:(1)农户间耕地利用行为具有差异性,耕地面积较大的兼业户表现出"高投入—低收益"特征,且农户类型存在动态变化的可能性;(2)经济发展水平较高的城市呈现以"高度兼业户"为主要农户类型的"单核心"分化趋势;(3)农户分化过程除大规模纯农户和高度兼业户的"终点"外,还存在对农业依赖较大的兼业户和耕地面积较大兼业户等"中间态"。研究结论:农户分化过程有律可循,应针对性地制定耕地利用政策加以引导。     

城镇化进程中水资源消耗的影响因素研究

在"多项连乘和加总"及向量扩展形式的LMDI模型基础上,构建城镇化进程中人口-居民消费-用水强度的分解框架,分析2003—2016年间水资源消耗的影响因素。研究表明:人口规模扩大和人口城镇化对用水量增长均为正向促进作用,且前者驱动力强于后者;居民消费水平提升是拉动用水量增长的主导因素,而居民消费结构优化升级和居民消费率上升均有效抑制了水资源的消耗,且前者更为显著;用水量的下降主要得益于产业技术进步,生活用水量的增长主要源于生活强度效应。进一步指出未来应合理控制我国人口规模和人口流动,加速居民消费结构的优化升级,注重强化产业技术创新,深挖农业节水潜力,提升居民消费率以实现既定经济规模下的相对节水。     

农村劳动力质量对规模农户生产效率影响研究

随着我国工业化与城镇化加速推进,农村领域大量劳动力以不同速度流向了非农产业,农村劳动力要素禀赋质量发生了巨大变化,农村劳动力要素禀赋质量的异质性对规模农户粮食生产效率的提高产生了深刻的影响。文章基于460户调查数据,运用Q型聚类方法将劳动力质量类型分为男性经验丰富型、女性经验丰富型、男性经验欠缺型、女性经验欠缺型四种类型,并利用随机前沿生产函数模型,计量检验了不同劳动力质量类型、劳动态度及劳动力市场发育等变量对家庭生产效率的影响。研究结果表明:男性经验丰富型与女性经验丰富型对家庭经济增长效率提升产生了显著的正效应,效应值分别为0.290、0.170,而男性经验欠缺型与女性经验欠缺型对生产效率提升产生了明显的负向影响,效应值分别为-0.110、-0.153,劳动态度、劳动力市场发育变量与家庭生产效率提升呈现了较强正、负相关性,效应值分别为0.590、-6.738。     

安徽省土地承载力研究

为服务土地管理实践,从耕地人口承载力、建设用地人口承载力的角度研究了安徽省及各市县的土地承载力,还从生态环境承载量的角度研究了建设用地最大量。研究结果表明,安徽省建设用地还有很大挖潜空间。按人均100m2计算,安徽省及各市建设用地人口承载水平在20%~40%之间。多元回归结果表明,区域常住人口、土地总面积对建设用地人口承载水平的影响显著。但GDP、人均GDP和二三产业占比对建设用地人口承载力的影响不显著。利用GIS的研究表明,在扣除生态必需用地后,安徽省建设用地生态适宜量为36 847km2,超过目前的建设用地总面积。耕地人口承载力研究结果表明,安徽省目前的耕地面积能满足全省常住人口粮食需求,但各市县差别很大。若不提高单产,在耕地面积不断减少的情况下,安徽省到2020年可能会面临粮食缺口。     

Sustainability of fish pond culture in rural farming systems of Central and Western Cameroon

In Sub-Saharan Africa, fish ponds are often an integral part of farming systems but have suffered from a lack of viability and sustainability. The present study aims to understand the strategies used by fish farmers to overcome economic and environmental constraints. In 2008 and 2009, fish farmers were surveyed in Central and Western Cameroon, and the fish production systems were classified by cluster analysis. Four broad types were identified according to the complexity of household operations. The development of extensive systems (large-scale and low-input) in rural areas of central Cameroon is induced mainly by abundant available land. For semi-intensive systems in both regions (small-scale and high-input in the Western Region, large-scale and high-input in peri-urban areas of the Central Region), horizontal integration is not sufficient to make fish production profitable and sustainable. More intensive fish farms tend towards vertical integration, in which farmers establish close links with input suppliers. Main causes of low productivity of semi-intensive systems (1–2?t/ha/yr) are both lack of knowledge of fish farming principles by farmers and lack of technical improvement by extension agents and researchers which need to consider the local complexity of farming systems to develop and intensify fish production. The adaptation of development strategies to socio-economic and environmental contexts is a necessity to hope for an increase in fish pond aquaculture production in Africa.     

Trade openness and household welfare within a country: A microeconomic analysis of Vietnamese households

The positive effects of trade liberalisation on several dimensions of poverty have initiated studies of the trade–poverty relationship. Trade liberalisation accompanies institutional reforms that help to reduce institutional barriers against the poor. This study examines the impacts of trade openness and institutional reforms on rural household welfare at the provincial level through the analysis of the determinants of welfare of rural households in Vietnam. The study employs a model of micro-determinants of growth and tests it on the data from the Vietnam Household Living Standards Surveys (VHLSSs) of 2006 and 2010. What makes the study different from some other studies of the same vein is that it attempts to directly capture the institutional effect on welfare. The study finds that, in the provinces with high institutional reforms and trade openness, the welfare of rural households improved. Institutional reforms in Vietnam appeared to be sluggish in the late 2000s. In particular, both access to land and lower informal charges were the important determinants of welfare improvement over time. These findings suggest that Vietnam should maintain its development by accelerating the process of institutional reforms, thereby helping poor households to improve standards of living.     

Education and the empowerment of women in household decision‐making in Spain

It was analysed whether investment in the education of both women and men serves to empower wives resulting in more balanced household decisions being taken on matters related to consumption and financial management. They considered that household decision‐making could be made by mainly the wife, mainly the husband or the couple acting jointly. They then applied multinomial probit models to the Spanish Living Conditions Survey of 2010. Results show that, when controlling for demographic, family and labour market characteristics, the level of education of both the husband and wife has a positive effect in terms of a more egalitarian decision‐making process in relation to three areas of expenditure: daily shopping, expensive purchases of consumer durables and significant expenditure on children. However, only women's education has a positive effect on borrowing money and no effect of education is observed with regard to the use of savings. Results are less conclusive for households where decisions are taken primarily by the wife or husband, since men's education increases the role of husbands in the household making‐decision process whereas no effect of wives' education is observed.     

平衡膳食模式视角下粮食需求预测

[目的]随着时代的进步和社会经济的发展,对粮食安全内涵的理解也在逐步深化,粮食安全内涵不仅包括数量方面,还包括营养健康安全,保障居民营养健康成为粮食安全的新时代内涵。基于营养目标的粮食需求研究,建立营养—消费—生产的粮食生产模式,对引导居民合理健康消费和保障粮食安全具有十分重要的意义。[方法]文章首先分析了我国城乡居民营养消费状况,然后基于平衡膳食模式视角,引入标准人消费系数这一概念对我国未来粮食需求进行了更准确的预测。[结果]城镇居民粮食消费已达到高营养目标,但目前农村居民仅达到低营养目标水平,相当于21世纪初的城镇消费水平;考虑人口结构因素,2020年和2030年粮食需求总量分别为4.8亿t和5.6亿t,比没有考虑人口结构变化时分别减少8700万t和2 600万t。[结论]根据分析结果,提出以下几点政策建议:(1)宣传普及营养健康消费知识,引导居民合理膳食;(2)关注人口结构变动,及时调整粮食安全调控机制;(3)优化食品工业的产业机构升级,提高饲料粮转化率。     

人口老龄化背景下的中国养老保险风险分析

伴随着我国人口老龄化的不断加速,社会保障尤其是养老保险领域的压力也随之加大,我国当前的养老保险体系也存在着一些现实问题与不足之处。而这都将导致在养老保险体系中固有的筹资、基金投资运营风险上升,同时也将出现制度与政策等新的风险。文章认为,需加强风险管理,不断完善养老保险制度,才能积极应对风险与收益的平衡。