保障功能替代与农民对农地转出的响应

农民转出农地的意愿将决定农地流转行为的发生,对农地流转市场的发育有重要的影响,因此研究农民转出农地的意愿具有重要的现实意义。本文基于对中国5省样本农民的问卷调查,运用Logistic回归模型,探讨了农地保障功能替代,尤其是就业保障功能替代与养老保障功能替代对农民转出农地意愿的影响。总体来看,农民转出农地的意愿较高,近四成农民愿意转出农地。回归结果显示,农地保障功能替代程度在一定程度上影响了农民转出农地的意愿。第一,农地就业保障功能在个人和家庭两个层面替代程度越高的农民,转出农地的意愿越高:主要从事非农工作的农民相对于主要从事农业的农民,转出农地的意愿更高;农民所在家庭劳动力转移程度越高,其转出农地的意愿越高。第二,以新农保为代表的农村社会养老保险对农地养老保障功能的替代程度越高,农民转出农地的意愿越高。虽然农民的参保状况与农民转出农地意愿的关系不显著,但是农民对新农保保障能力的评价越高,那么其转出农地的意愿越高。同时研究还发现,不同性别、年龄、文化程度、身体健康状况、家庭规模的农民转出农地的意愿也存在显著差异。基于上述研究结论,为促进农地流转市场的发育,实现农地资源的优化配置,本文提出了促进农民非农转移和建立健全农村社会保障体系的政策建议。     

非农就业、社会保障与农户土地转出——基于30镇49村476个农民的实证分析

基于江苏省沭阳县的调查数据,对农民非农就业、社会保障与其土地转出意愿与行为的关系进行了实证分析。首先,结构方程模型(SEM)研究结果表明,土地所具有的多重功能价值对农民的土地流转意愿具有重要影响。其中土地的直接经济价值与农民土地转出意愿呈现出负相关关系;土地转出预期价值对农民土地转出意愿的影响最大,农民土地转出的预期回报对意愿具有显著的正向影响;若有完善的非农就业环境与社会保障制度能代替土地本身承载的就业价值与社会保障功能,则会对农民土地转出意愿产生积极的正向作用。其次,Probit和Tobit模型计量检验结果表明,具有非农就业经验以及家庭非农劳动力越多的农民转出其土地的可能性越大,转出的面积也越多;农民参加的社会保障水平越高,土地的保障性功能相对就越小,农民对土地的依赖性越低,从而转出其土地的可能性越大,转出的面积也越多。在此基础上,得出了要大力发展非农产业,营造良好的外部就业环境,进一步完善农村社会保障体系等政策启示。     

劳动力转移、性别差异与农地流转及合约选择

通过构建“劳动力转移-性别差异-农地流转及合约选择”分析框架,分析劳动力转移性别差异背后的行为经济学含义,进而探讨不同性别的劳动力转移对农户农地流转供给决策与合约选择的差异化影响机制。理论研究表明,女性在家庭中起粘结家庭成员的作用,女性劳动力非农就业更能体现家庭的“离农”,因而女性劳动力的非农就业行为对农户农地流转供给决策具有更明显的促进作用;男性是农户家庭在村庄中排他能力的标志,具有不可忽视的农地流转风险规避功能,因而男性劳动力的外出就业距离对农户农地流转的合约选择起决定性作用。利用全国9省(区)4772个农户样本数据进行实证分析,计量结果表明:①女性劳动力非农就业比例每增加10%,农户转出农地面积占承包地面积比例增加1.06%;②男性劳动力县外就业比例每增加10%,农户转出农地时签订关系型合约的可能性增加1.11%;③男性劳动力县外就业比例每增加10%,意愿合约形式为无合同的可能性增加0.63%,意愿合约形式为口头合同的可能性增加0.29%,意愿合约形式为书面合同的可能性减少0.91%。这意味着,为了劳动力流转市场与农地流转市场更流畅地互动,应为农村女性劳动力营造一个更加合适、有利和公平的非农就业环境,这可成为未来农村劳动力就业扶持政策的重要方向。另一方面,促进正式契约与关系型合约的有机衔接,有利于农地流转合约的正式化与规范化,从而为农地流转市场的健康发育提供有力保障。     

家庭生命周期对农户农地转出行为的影响研究——基于秦巴山区农户调查数据的实证分析

根据家庭生命周期理论内涵与外延，利用秦巴山区456户微观样本，运用统计分析法和Heckman两阶段模型，分析家庭生命周期对农户农地转出行为的影响。研究发现：家庭生命周期对农户农地转出行为有显著影响；处于不同家庭生命周期阶段的农户农地转出行为的影响因素存在差异。从人力资本来看，良好的劳动力健康状况不利于赡养期家庭参与农地转出，非农就业率对抚养期、负担期家庭参与农地转出有显著正向影响；从农户认知来看，限制农地用途，了解流入方，村委会推动、政府主导型转出均在不同程度上增加各阶段农户转出农地的可能性；对于拥有较多非农就业机会的抚养期和负担期家庭而言，农地确权通过强化地权稳定性促使其转出农地并外出务工。因此，在实践中执行农地流转政策时，应采取精准的农地转出激励措施，差别化对待不同生命周期的家庭。     

个人特征、家庭特征对农村非农就业影响的实证

工业化对于一个国家或地区经济腾飞的重要性,已经被西方发达国家的经验和道路所证实。在实现工业化的过程中,农村劳动力转移是世界各国都曾经或必将面对的重要课题。本文运用行为主义研究方法,利用2003-2006年全国农村固定观察点的数据,建立Probit模型实证分析了农民个体特征和农户家庭特征对农村非农就业的影响。研究发现:就样本个人特征而言,户主或家庭主要经营者、男性、文化程度较高、身体健康的农民从事农村非农就业的意愿更强,职业教育或培训对于农村非农就业有明显的促进作用,而是否农业户口对农村非农就业的影响并不明显。就样本家庭特征而言,家庭类型会影响农民在农村的非农就业倾向,同时,乡村干部户从事非农产业的倾向性更强,少数民族户和信教户从事非农产业的倾向性较弱,"是否国家干部职工户"、"是否党员户"对农村非农就业的影响并不显著。重视农民的个人特征和家庭特征差异,大力发展农村非农产业,促进农村非农就业是我国政府解决农村剩余劳动力转移问题的重要战略选择。     

农地分配制度不是农地冲突的根本原因——基于湖北和湖南农村问卷调查的实证分析

农地冲突是当前我国农村经济发展和城镇化进程中的普遍问题,在—些地方相当突出,严重影响了农村的社会稳定和经济发展,探讨农地冲突的原因有助于化解农村矛盾及构建和谐繁荣的农村社区。本文利用笔者在湖北和湖南两省收集到的数据,应用Logit概率模型实证分析了农地分配制度、非农就业收入及其差距和人力资本等可能引起农地冲突的因素的影响。与通常的看法不同,本文并没有发现农地分配制度是农地冲突的显著诱因,原因可能在于我国的农地在改革初期是按人口或劳动力平均分配的,其后的调整大多也是经农民自主协商按照市场规则完成的,并没有引起农民的明显不满,因而也就没有成为农地冲突的诱因。本文的研究结果还表明,非农就业收入、非农就业收入差距和家庭人力资本对农地冲突的影响显著,非农就业收入越低,其差距越小,家庭人力资本越多,农地冲突发生的概率越大,是农地冲突的主要诱因。这表明非农就业收入越少,农民通过非农就业增加家庭收入的隧道效应越弱,对农业收入的依赖性越大,农地就越重要,农地冲突越容易发生;家庭男性成员越多,家庭社会地位越高,在打架斗殴和上访诉讼中越占优势,农地冲突也越容易爆发。因此,为了减少农地冲突,应采取切实措施,促进农村劳动力向非农部门转移,加强农村法制建设,限制丛林行为。     

农民分化对农户农地流转意愿的影响研究

农地使用权流转是解决当前我国农村土地利用细碎化及撂荒的有效途径,对于提高土地利用效率、促进农业结构调整和农民增收具有重要作用。农户是农地流转中主要的土地供给者,他们的意愿和行为直接影响农地使用权的流转。然而,当前农民已经分化为不同阶层,有其各自的阶层属性与认知,这对农地流转意愿必然会产生影响。因此,本文利用农户调查数据,运用有序Probit模型和结构方程模型(SEM)实证分析了农民分化对农地流转意愿的影响。结果表明:农民分化特征对农地流转意愿的影响在5%水平上显著,而且农民分化特征每提高一个单位,农户农地流转意愿就会增加0.634个单位。在反映农民分化程度的两个可观测变量中,职业分化程度和经济分化程度每提高一个单位,农户进行农地流转的概率就会分别增加21.7%和36.4%。此外,反映其它潜变量的可观测变量中,年龄、文化程度、是否具有非农就业技能、家庭农业劳动力人数、对农地产权稳定性的认知、流转地在养老保障中的作用和是否参加社会养老保障等变量对农地流转意愿具有显著影响效应。在此基础上,得出相应的政策启示。     

政府干预农地流转:农户收入及资源配置效率

本文基于江苏省苏北地区灌云县和金湖县的农户调研,采用内生性处理回归模型考察政府干预下土地流转对不同类型农户收入的影响,并从农户土地和劳动力资源配置效率的角度解释农户收入变化的根源。研究结果表明,政府干预下土地流转对不同类型农户收入的影响效应有很大差异,农户土地转入后收入增加了161.2%,转出户收入并未显著增加;从农户资源配置角度考察,发现农户转入土地后农业生产效率显著提高,转出土地后农业生产率降低;农户土地转出后非农工作时间和工作报酬并未显著增加,表明转出户并未提高非农劳动力资源配置效率。同时,本文比较政府主导和农户自发两种类型农地流转对农户收入和资源配置效率的影响差异。结果发现,相对于自发土地流转的农户,政府主导下农户转入更大面积土地,并显著提高了单位面积土地生产效率和家庭收入水平;而政府干预土地转出不利于农户土地和劳动力资源配置效率及收入水平的提高。基于以上分析,本文认为政府干预降低了土地流转交易费用,有利于转入户扩大土地面积,实现规模经济效益,进而增加转入户收入;然而,政府干预下转出户资源配置面临较大约束,配置效率和收入都未能实现最大化。因此,政府在完善农地流转服务政策的同时,应当尊重农户土地流转意愿,使得农户土地流转符合家庭资源配置收入最大化目标。同时,要通过非农就业培训、发展非农经济,吸纳更多劳动力转移到非农业领域,进一步促进农村土地流转和规模经营,优化农村土地和劳动力资源配置效率,持续增加农民收入。     

生计资本异质对农户农地流转行为的影响——以武汉城市郊区的516户农民为例

以武汉市城郊江夏区和蔡甸区的516户农民家庭为实证,运用logistic和分位数回归模型探索家庭生计资本对农户土地流转行为的影响及阈值。结果表明:(1)人力资本和金融资本与农户农地转出行为呈显著正向相关,家庭农地资源禀赋、机耕能力、社会资源禀赋及经营能力的信任程度等与农地转出行为负向相关。相反,自然资源禀赋及农业机械投入对农户土地转入行为的正向影响显著,而家庭融资能力则对农户转入行为呈显著的负向影响。(2)分位数回归结果显示,对农户土地流转行为存在影响阈值的仅有韧性指数。当农户家庭韧性指数≤2时,随韧性指数增强农户农地转出倾向愈强;家庭韧性指数≥3时,农户农地转出倾向随指数增强而弱化。该研究从农户微观个体视角探索生计资本异质对农地流转行为的影响,为针对农户家庭需求制定差别化的农地流转政策、有效推进农业适度规模经营提供建议参考。     

农地确权的收入效应

农地确权是农村土地产权制度改革的一项重要举措,对提高农户家庭收入有重要的积极作用,但其收入效应研究尚未受到足够重视且缺少更严谨的证明。本文基于浙江大学2017年中国农村家庭调查数据(CRHPS),借助普通最小二乘法(OLS)和倾向得分匹配方法(PSM),实证考察了农地确权的收入效应,并构建了一个中介效应模型,从土地流转和劳动力非农就业两个因素实证分析了农地确权的收入效应机制。研究发现:①农地确权能够显著提高农户家庭人均总收入和工资性收入,对其他类型收入的影响不显著,但OLS方法高估了农地确权的实际增收效果。②土地流转的中介作用并不明显,但从长期来看,农地确权有促进土地转出和抑制土地转入的趋势。③农村劳动力转移是农地确权提高农户家庭收入的有效路径,农地确权促进了农业劳动力转向生产效率更高的非农生产,通过直接提高农户家庭工资性收入增加了农户家庭总收入。④农地确权的收入效应在东部地区不显著,在中部地区和西部地区显著,原因可能是东部地区经济发展和就业机会相对较好,农户家庭在生产生活方面普遍向城镇转移,导致农地确权带来的土地安全感知不明显,影响了农地确权激励剩余劳动力转移的积极作用,进而影响农户增收效果。研究认为,农地确权工作结束后,为促进不同地区的农户家庭持续稳定增收,应尽快完善相关配套制度,具体包括宣传农地确权政策,扩大农户非农就业机会,完善土地流转市场,发挥土地财产功能等。     

Present status of Rn in groundwater in Extremadura

Radon-222 was measured in groundwater sources of Extremadura (Spain), analyzing 350 samples from private and public springs, wells, and spas by liquid scintillation counting (LSC) and gamma spectrometry. The ²²²Rn activity concentrations ranged from 0.24 to 1168 Bq L⁻¹. The statistical analysis showed a log-normal distribution with a mean of (111 ± 7) Bq L⁻¹ and a median of (36 ± 3) Bq L⁻¹. A hydrogeological study revealed correlations between the activity concentration and the aquifer material's characteristics. A map of ²²²Rn in groundwater was elaborated and compared with the natural gamma radiation map for this region. About 35% of the samples showed ²²²Rn activity concentrations above the Euratom recommended limit of 100 Bq L⁻¹. Three uranium series radionuclides (²³⁸U, ²³⁴U, and ²²⁶Ra) were also assayed by alpha-particle spectrometry, estimating the annual effective dose due to the presence of these natural radionuclides in drinking water.     

Reuse of mining wastewater in agricultural activities in Jordan

A pilot study was completed in the Al-Abyad area near phosphate mining activity in Jordan. Six plots of 50 m² each were planted with two types of plant species (Zea mays spp. and Medicago lupulina spp.) and irrigated using three types of water (fresh groundwater, mine wastewater, and hydride water consisting of 50% fresh and 50% mine wastewater) to investigate the suitability of utilizing mine wastewater for food production in the area. Water, soil and plant sampling was completed for each plot over different time intervals and analyzed for heavy metal (Cr⁺⁶, Ni⁺², Zn⁺² and Pb⁺²) in addition to major ionic composition of the water used for irrigation. Crop yield was estimated at the end of the experiment. Plots irrigated with mine wastewater showed slightly higher heavy metals concentrations and soil salinity during the experiment period was higher for plots irrigated with mine wastewater compared to plots irrigated with fresh water, and it was uniform through the upper 45 cm of the soil profile due to the high amount of irrigation water used during the experiment. Crop yield was inversely proportional to salinity as an increase of salinity by 2-folds resulted in reducing yield by almost 50%. However, no risk of heavy metals contamination was found in plants and soil. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Concentration and characterization of plutonium in soils of Hubei in central China

To study the Pu concentration and isotope ratio distributions present in China, the ^239+240Pu total activities and ²⁴⁰Pu/²³⁹Pu atom ratios in core soil samples from Hubei Province in central China were investigated using Accelerator Mass Spectrometry (AMS). The activities ranged from 0.019 to 0.502 mBq g⁻¹ and the ^239+240Pu inventories of 45 and ∼55 Bq m⁻² agree well with that expected from global fallout. The ²⁴⁰Pu/²³⁹Pu atom ratios in the soil ranged from 0.172 to 0.220. The ratios are similar to typical global fallout values. Hence, any close-in fallout contribution from the Chinese nuclear weapons tests, mainly conducted in the 1970s, must have either been negligible or had a similar ²⁴⁰Pu/²³⁹Pu ratio to that of global fallout. The top 10 cm layer of the soil contributes ∼90% of the total inventory and the maximum concentrations appeared in the 2-4 cm or 4-6 cm layers. It is suggested that climatic conditions and organic content are the two main factors that affect the vertical migration of plutonium in soil.     

Evaluation of Urban Sustainability in Specific Sectors in Latvia

In Latvia, the concept of sustainability is only slowly gaining recognition. An analysis of Development Plans prepared by the four largest cities of Latvia indicates that sustainability is presented as one of the guiding principles. However, a comparison of Development Plan policies against the urban sustainability issues reveals a great deal of ambiguity and contradiction.At the municipal level, planners and politicians lack indicators to gauge whether the long-term goals of Development Plans and the principles of sustainable development are being achieved. As a consequence, the broad public is deprived of the opportunity to assess for itself the process of development in relation to Development Plan policies, thus limiting accountability in development decision-making. Relevant statistical data collected on a regular basis are required to create sustainability indicators reflecting sustainability issues, to supplement and replace existing statistical compilations pertaining almost exclusively to economic growth and consumption. Development and utilisation of sustainability indicators can be an effective instrument for promoting the values of sustainable development amongst politicians, planners and the broad public and for enhancing accountability in decision-making.     

Radionuclides in terrestrial ecosystems of the zone of Kyshtym accident in the Urals

It was shown that along the Eastern Ural Radioactive Trace central axis, about 100 km in length, decrease of the ⁹⁰Sr and ¹³⁷Cs deposition densities in soil samples may be described as an exponential function. At the western and eastern periphery of the trace, ⁹⁰Sr contents in soils approached to the background level due to global fallout. ⁹⁰Sr and ¹³⁷Cs concentrations in seeds of some herbaceous plants have been determined. The radionuclide concentrations and the resulting dose loads upon plant seeds showed an excess over the background level of about two or three orders of magnitude.     

Diffusion of Lead-free Soldering in Electronics Industry in China

The EU directives on e-waste management (WEEE and RoHS) have drawn the attention of electronics producers around the world to the environmental benign technologies in recent years. One of the technological challenges to the electronics manufacturers is the adoption of the lead-free soldering system. This article studies the diffusion of lead-free soldering technology among the electronics producers in China, and finds out the relevance of clusters for the diffusion of environmental benign technological innovation among firms. Four agents, as key promoters, were identified within the production network –leading global brand-name companies, the OEM companies who provide integrated manufacturing service, the suppliers of lead-free components, and specialized consultant companies. The conclusion is that industrial cluster facilitates communications among all agents for the diffusion of innovation, whereas, the incentives for firms within the cluster, to collaborate for innovation, comes from outside.     

Effect of Increase in Price of Oil on Behavior of Private Car Owners in Beijing

In order to understand the short-term response of private car owners to changes in the price of oil, a survey was conducted in Beijing after the gasoline price in China rose in June 2008. It showed that private car drivers in Beijing reduced their trips in the one month period following the price adjustment. Certain trip characteristics and drivers' demographics significantly influenced price elasticity in the short term, including the purpose of the trip, the distance covered and the income of the car driver.     

Dynamics of Habitat Distribution in Birds Differing in the Level of Site Tenacity

The dynamics of habitat distribution in two bird species differing in the level of site tenacity—willow warbler (relatively tenacious) and little bunting (more flexible)—were studied at the boundary of the northern taiga and forest–tundra zones over ten years. The distribution pattern proved to be more uniform in the willow warbler than in the little bunting. Both species occupied their habitats according to a well-known scheme: initially, the birds settled in their favorable floodplain habitats and later; when their abundance increased, in less preferable habitats (terraces above the floodplain, moss bogs, and the tundra). In the case of willow warbler, the process of occupying the floodplain was stepwise: bird density increased sharply, remained at the same level in the next year, then increased again, etc. In the case of little bunting, the degree of floodplain occupation by birds remained high, except for the years when high spring floods interfered with bird settling.     

Ecophysiological Parameters of Transpiration in Coniferous Woody Plants in Phytocenoses of the North

Long-term observations on needle transpiration in pine and spruce, the main forest-forming tree species in the North, made it possible to estimate the rate of this process depending on different ecological factors in years with different weather conditions. Using a large amount of data, an attempt was made to compare transpiration rates in pine and spruce and reveal some specific features of this process under conditions of the North.