不同主体功能区农户家庭耕地利用功能对土地流转行为的影响

城乡经济转型及农村人口快速城市化促使农户家庭耕地利用功能较传统利用方式发生转变,农户家庭耕地生存依赖度弱化促进土地流转市场发育。以湖北省重点开发区、农产品主产区和生态功能区的1 146户农户调查数据为实证,运用Biprobit模型分析不同主体功能区农户家庭耕地利用功能对土地流转行为的影响。研究表明:(1)调研区域41.10%的农户家庭参与土地流转,土地流入转出租金分别为2 751.12元/hm~2、4 391.33元/hm~2,土地流转发生率较高但租金水平整体偏低,且在区域间存在显著差异。重点开发区土地流转市场发育较好,流转参与率及租金水平较高;农产品主产区流转参与率较高,但租金水平较低;生态功能区土地流转参与率及租金水平较低,流转市场发育迟缓。(2)区域间功能定位、经济发展水平的差异导致农户家庭耕地利用功能空间差异明显。其中,生态功能区农户耕地资源利用的食物生产功能弱化明显,而重点开发区和农产品主产区则明显弱化耕地资源的养老就业功能。(3)整体而言,农户家庭耕地利用功能对土地流转行为影响显著。其中,家庭耕地利用在经济贡献、养老就业及食物生产等方面承担的功能越强,其家庭做出土地转出决策的可能性愈小;而选择土地流入的可能性也越大,而家庭耕地利用所表征的选择馈赠功能越强,其家庭越倾向于留存土地,且区域差异明显。重点开发区的相关系数及显著程度较高,作用方向与整体基本一致;生态功能区的相关系数及显著程度最低,且作用方向偏离整体幅度较大。表明经济发展程度越快的地区,土地流转发育受耕地利用功能的影响越明显。     

THE OPPORTUNITY COST OF TIME AND AVERTING EXPENDITURES FOR SAFE DRINKING WATER1

ABSTRACT: A survey of individuals during a Giardia contamination incident provided data to calculate the cost of boiling, hauling, or purchasing water to avoid infection. Three different approaches to the valuation of time were used to assess the implications of the opportunity cost of time for the measurement of averting costs. Mean monthly household averting costs were $33.47 using family income to value time, $13.07 using the minimum wage to value time, and $5.60 using zero opportunity cost of time. Comparisons of the mean costs for different sources and household characteristics indicated the value of time from family income was too high and that the other methods of valuing time were superior.     

Putting Density Back into the Habitat‐Quality Equation: Case Study of an Open‐Nesting Forest Bird

Abstract: Ecological traps and other cases of apparently maladaptive habitat selection cast doubt on the relevance of density as an indicator of habitat quality. Nevertheless, the prevalence of these phenomena remains poorly known, and density may still reflect habitat quality in most systems. We examined the relationship between density and two other parameters of habitat quality in an open‐nesting passerine species: the Ovenbird (Seiurus aurocapilla). We hypothesized that the average individual bird makes a good decision when selecting its breeding territory and that territory spacing reflects site productivity or predation risk. Therefore, we predicted that density would be positively correlated with productivity (number of young fledged per unit area). Because individual performance is sensitive to events partly determined by chance, such as nest predation, we further predicted density would be weakly correlated or uncorrelated with the proportion of territories fledging young. We collected data in 23 study sites (25 ha each), 16 of which were located in untreated mature northern hardwood forest and seven in stands partially harvested (treated) 1–7 years prior to the survey. Density explained most of the variability in productivity (R²= 0.73), and there was no apparent decoupling between density and productivity in treated plots. In contrast, there was no significant relationship between density and the proportion of territories fledging ≥1 young over the entire breeding season. These results suggest that density reflects habitat quality at the plot scale in this study system. To our knowledge this is one of the few studies testing the value of territory density as an indicator of habitat quality in an open‐nesting bird species on the basis of a relatively large number of sizeable study plots.     

Using deep-belief networks to understand propensity for livelihood change in a rural coastal community to further conservation

Overharvesting of terrestrial and marine resources may be alleviated by encouraging an alternative configuration of livelihoods, particularly in rural communities in developing countries. Typical occupations in such areas include fishing and farming, and rural households often switch livelihood activities to suit climate and economic conditions. We used a machine-learning tool, deep-belief networks (DBN), and data from surveys of a rural Philippine coastal community to examine household desire to change livelihood. This desire is affected by a variety of factors, such as income, family needs, and feelings of work satisfaction, that are interrelated in complex ways. In farming households, livelihood changes often occur to diversify resources, increase income, and lessen economic risk. The DBN, given its multilayer perceptron structure, has a capacity to model nonlinear relationships among factors while providing an acceptable degree of accuracy. Relative to a set of 34 features (e.g., education, boat ownership, and work satisfaction), we examined the binary response variables desire to change work or not to change work. The best network had a test set accuracy of 97.5%. Among the features, 7 significantly affected desire to shift work: ethnicity, work satisfaction, number of persons in a household in ill health, number of fighting cocks owned, fishing engagement, buy-and-sell revenue, and educational level. A cross-correlation matrix of these 7 features indicated households less inclined to change work were those engaged in fishing and retail buying and selling. For fishing, provision of economic and other incentives should be considered to encourage changing from this occupation to allow recovery of fishery resources.     

代际差异视角下农民工乡城迁移与宅基地退出影响因素分析——基于推拉理论的实证研究

在2011年天津市农民工调查数据的基础上,本文借鉴推拉理论重新梳理影响农民工城乡迁移与宅基地退出意愿的因素,建立了农民工宅基地退出影响因素的推拉分析框架,并通过实证研究析出和显化在不同代际农民工城乡迁移和宅基地退出过程中起关键作用的因素。研究发现:在推力因素方面,对第一代农民工宅基地退出意愿产生较大影响的因素主要是年龄、受教育程度、宅基地在住房养老中的作用、供养系数和对农村基础设施满意程度;对新生代农民工宅基地退出意愿产生较大影响的因素主要有性别、教育程度、供养系数和对农村基础设施满意程度。在拉力因素方面,对第一代农民工宅基地退出意愿产生较大影响的因素主要是有无专业培训经历或证书、是否签订劳动合同、区位、单位性质和外出务工时所利用的方式;对新生代农民工宅基地退出意愿产生较大影响的因素主要是有无专业培训经历或证书、是否签订劳动合同、区位、单位性质、外出务工时所利用的方式和是否同城里的人交过朋友。在此基础上,提出了相应的政策建议。     

Orientation experiments with displaced juvenile barn swallows (Hirundo rustica) during autumn migratory season

In a previous paper, we reported that juvenile barn swallows (Hirundo rustica) trapped during the autumn migratory season and tested in modified Emlen funnels under overcast conditions can use magnetic information for compass orientation, although they did not orient toward the expected migratory direction. To further investigate this behaviour, in the present paper, we report the results of two series of displacement experiments performed on juvenile barn swallows belonging to two different roost sites [Massaciuccoli Lake (ML) and Terzo Cavone (TC)] and tested using the same protocol as that previously adopted. On the whole, the outcome of the ML and TC experiments was quite different with respect to (a) the degree of bird activity within the funnel (substantially lower for TC) and (b) the effect of the experimental displacement on the directional preferences of the tested subjects (not detectable in TC, while evident in ML swallows). Taken together, these results suggest that migrating swallows could react differently to the experimental tests depending on the roost site where they were caught. Indeed, TC swallows, trapped in southern Italy, close to the seacoast, and characterized by fairly large amounts of fat stores, mainly broke off their migratory activity or reoriented their directional preferences toward inland sites, possibly in search of more profitable habitats. On the other hand, ML swallows, trapped about 660 km to the north and characterized by lower amounts of fat stores, apparently tried to compensate for the experimental displacement.

农民工工伤保险现状及问题分析

通过文献分析和实地调研发现,造成我国农民工工伤保险参保率低、企业逃保、退保率高、申请工伤补偿难度大的原因可分为宏观和微观两个层面:城乡二元户籍制、劳动力供求关系、工伤保险制度等因素客观上使得农民工受歧视,地位低,工伤求偿困难;企业主观上追求短期利益和侥幸心理是构成其逃保、退保的主要因素.可通过优化制度体系、强化政府监管...     

农民工参加工伤保险的影响因素研究——基于政策和企业视角的实证分析

为了解我国农民工参加工伤保险的影响因素,提高农民工工伤保险的参保率,通过对全国9个省市共3 848名农民工的问卷调查,应用Logistic回归模型分析政策的因素和企业的因素对农民工参加工伤保险的影响。结果表明,农民工是否参加工伤保险受到各地工伤保险政策以及农民工所在企业两方面的影响。从政策的角度看,个体工商户参加工伤保险的规定、工伤保险基金的统筹水平以及工伤保险的偿付方式对农民工参加工伤保险有显著影响;从企业的角度看,农民工所在企业是否建有工会、企业所有制对农民工参加工伤保险有显著影响。建议各地进一步明确工伤保险政策中对个体工商户的参保要求,继续提高工伤保险基金的统筹水平,增加农民工领取工伤保险偿付的方式。建议劳动保障部门加强对未建有工会的企业,加强对私企,特别是个体工商户的监察力度。     

影响农民工职业安全健康需求的自身因素分析

农民工群体为国家经济发展做出了重要贡献,但其职业安全健康状况却令人担忧。通过文献整理发现,农民工自身职业安全需求低是造成这种现象的重要原因之一。从农民工自身角度来分析,来自以下四方面的原因共同制约着农民工对职业安全的需求：（1）农民工知识结构欠缺、工作年限普遍较短、缺乏对职业安全的认知意识,影响农民工对职业危害的认知;（2）来自家庭的增收压力和降低寻找工作的间接成本的要求造成了目前农民工经济压力大的状况;（3）自身技能水平较弱以及缺乏对就业信息的分析能力,削弱了他们的就业竞争力;（4）农民工群体之间缺乏沟通信任以及长期的低社会地位限制了他们的谈判能力。以上四方面原因相互作用,产生效力叠加,共同导致了目前农民工职业安全需求不足的状况。