The fight against coronavirus disease 2019 (COVID-19) is still running its courses. Proper management and disposal of health care wastes (HCWs) are critical to win the fight. To achieve aforementioned tasks, prediction of their production is highly desired. In this study, primary data of production of three kinds of HCWs collected from Wuhan, the first epidemic epicenter worldwide and a mega city with more than 10 million population who has went through a lockdown period of 78 days, were reported for their first time. HCWs were classified into routine HCWs, infectious HCWs (IHCWs) and infectious municipal solid wastes. Among them, infectious HCWs from designated hospitals for COVID-19 were recognized as the most dangerous one. A multiple linear regression (MLR) model was built to predict the production of IHCWs with high significance. Numbers of patients were demonstrated high correlations with the production of IHCWs in an order of confirmed patients > out-patients > suspected patients. By the MLR model, production rates of IHCWs by confirmed, suspected and out patients were determined as 3.2, 1.8 and 0.1 kg/patient, respectively. In addition, constant production of IHCWs during the pandemic period was determined as 13 tons/d. This is the first study on quantitative evaluation of infectious HCWs during COVID-19 pandemic. The achievements in this study have potentials to shed light on global efforts to the prediction, management and disposal of vast HCWs generated in the war against COVID-19. (c) 2021 Elsevier Ltd. All rights reserved.

1研究亮点 * COVID-19暴发期间武汉市将医疗废物分为3类进行管理; *首次报道了武汉市封城期间涉疫医疗废物的第一手数据; *涉疫医疗废物产生量与医疗资源的消耗量呈现明显正相关关系; *建立了 COVID-19暴发期间武汉市涉疫医疗废物预测的多元线性回归模型. 2背景 COVID-19疫情暴发期间,武汉市投入了大量医疗资源用于疫情防控,随之带来大幅增长的涉疫医疗废物.全国范围内医疗废物产生量从2020年1月20日的4 902.8 t/d增长至2020年3月21日的6 606.8 t/d,武汉市的医疗废物产生量更是从疫情暴发前的40～50t/d增长至2020年3月1日的247 t/d.爆炸性增加的产生量对武汉市的涉疫医疗废物收运管理和终端处理带来了极大的挑战.因此,本研究对武汉封城期间3类医疗废物的产生量变化趋势及其与相关病患数量、医疗资源消耗情况的相关性进行了分析,并构建了多元线性回归模型,准确地拟合了涉疫医疗废物的实际产生量.

文章基于2010、2012和2014年中国家庭动态跟踪调查(CFPS)数据,利用中国退休政策在男女退休年龄上的规定,使用断点回归设计,探讨退休对身体健康和心理健康的影响,并检验退休影响健康的机制.研究发现,退休对男性的健康影响不显著,而对女性的自评健康和心理健康产生显著正向的影响,主要原因是退休后女性增加了锻炼的频率;虽然男性的锻炼频率在退休后也有所增加,但退休后男性超重的概率也随之增加,这很可能在一定程度上抵消了锻炼的健康效应.文章具有明显的政策含义,当前中国政府正在考虑实施渐进式延迟退休政策以应对人口老龄化背景下劳动力不足的问题,研究表明延迟退休不能够以牺牲老年人口的健康为代价,中国需要切实推进“健康老龄化”的战略.

对社会冲突成因及解决机制的经济学分析日益得到主流经济学界重视.在理论上,研究者以竞争成功函数为基础,考虑了产权不完善、信息不对称、集体行动机制等视角如何解释社会冲突成因,同时也关注理性选择之外的情感因素.在实证中,学者们反思早期研究中使用经济发展、不平等、社会分隔等因素解释冲突成因时的不完善之处,通过纳入空间变量、构建“极化”指标等方法,使实证分析结论更为清晰.此外,也有一些研究者通过实验方法模拟冲突环境、验证冲突理论模型,并探究具体因素如何影响冲突的发生.在解决机制方面,现有结论包括构建谈判与妥协机制,增加国家能力等.

土地冲突是单位或个人为了取得、捍卫、行使土地权益或者排除他人干预而采取的谩骂、中伤、聚集、斗殴、对抗并造成人员伤亡、财产损失或较大社会影响的过激行动.目前,我国土地冲突的分类体系还无明确的定论,但有一部分学者对此进行了研究.本文主要综合这些学者的观点从产权主体、时间进程及冲突的内容这几个角度对农村土地冲突的分类进行概述,深入探讨了土地冲突发生的原因及其演变机制,针对我国土地冲突的现状分别从利益、权力权属及政策制度层面概述相应的治理机制,并提出土地冲突未来研究仍需深入、完善的方面.

Different methods of public policy analysis should be used at different stages of the strategic designing of the Five-Year Plans.First,in the process of analyzing the background of the Five-year Plans designing,a large sum of information and data should be collected,and situation diagnosis meth-od should be adopted to describe the efficiency and performance of the past policies and to explore the solutions for current key issues or problems that will emerge in the future.Second,the mixed-scanning model should be applied to identify a clear policy direction and the major missions and strategies for the next five years.Third,the target designing should be approached from the perspectives of"system outlook"and"top designing",to construct a general target frame with the systematic planning meth-od.Fourth,after the policy obj ective is chosen,the system evaluation method should be utilized to e-valuate and determine the best policies.Finally,policy assessment is also essential for pushing for-ward the implementation process.Presently,some improvements are demanded in the design of the Five-Year Plans,such as the unclear positioning,imperfect cohesive devices and decision-making mechanism,and lack of legal basis in the making and implementation of the plans.Legalization of the Five-Year Plans should be strengthened in the future.

休闲农业如何出现区域集聚,又如何应对由于集聚带来的“拥堵”问题,及时实现产业升级和价值链提升？通过一个案例研究,本文认为,地区个体之间的“强联系”,以及区内个体与外部个体之间的“弱联系”,是推动地区休闲农业集聚和升级的“双重驱动机制”.随着时间的推移,创业者个体与其所“嵌入”的社会网络之间不同的互动关系,会导致差异化的发展路径,并对其所“嵌入”的社会关系网络带来不同的反作用.能成功强化内部“强联系”,甚至将部分“弱联系”整合为“强联系”的创业者,在后续的创业发展和升级中表现更佳.而“领军者”们的成败也决定了“追随者”的态度和行为选择,不成功的创业经历会反过来抑制其“强联系”社会网络中潜在创业者的创业意愿.据此,本文提出,在制定区域休闲农业发展政策时,应高度重视乡村社区内潜在创业者的社会网络结构培育问题,这可能比短期内进行大规模基础设施建设的意义更大.

作为生态文明建设的重要部分,森林建设日益成为公共管理事务中关注的焦点。本文利用我国第二至第七次森林清查省际面板数据,建立动态面板模型,使用系统广义矩估计方法,对改革开放以来我国森林资源变动与经济发展关系进行检验。此外还使用1978—2008年的全国森林资源数据对面板分析所得趋势进行了验证。实证结果显示:①基于改革开放以来的森林清查省际面板数据,中国的森林资源变化与经济发展水平间的关系保持共同增长的趋势,全国森林变动与人均GDP的数据也进一步验证了面板计量结果所反映的趋势;②基于目前结果无法判断近30多年来中国森林资源变动与经济发展间存在环境库兹涅茨曲线所描述的U形关系。

<正>北京市100万亩平原造林是一个生态建设创新实践的成功案例,为地方政府如何有效提供生态公共产品,如何制定生态政策,如何以科学民主而高效的方式执行生态政策提供了可资借鉴的思路。为此,清华大学国情研究院组成调研组,以这一项目为例进行调查研究,旨在介绍和总结地方绿色创新、绿色投资、绿色发展情况,为全国各地创新生态建设提供可供参考的经验。那么,北京市100万亩平原造林项目的有效实施基于怎样的生态政策过程,取得了哪些成效,积累了哪些创新经验,下一步又应在哪些方面继续推进呢?

当前农村居民面临着严重的环境污染侵害,相应的维权渠道建设未臻完善,带来不满情绪的积累和一些群体性事件的发生。本文从认知度、评价、选择倾向及原因等多个角度对农村居民可选择的环境维权渠道进行实地调查,并提出相应的对策选择。

The paper describes the change of connotation and ideas of"Green Economy". The ideology of forestry development has been enriching constantly because of the Chinese academia’s acceptation with the development of green economy. Forestry plays a fundamental role in the system of green economy. The profound transformation and innovations are necessary to help fulfill the function.

There were some illegal behavior and violent conflict in rural election of China.This study wanted to know what the critical factor is and how to resolve that.For this purpose,this study develop a simple frame which come from common-pool resources competition and institutional supply theories to predict the effects of rural collective resources and upper governance structure on the election conflict.Using a data set and some cases form field survey,this paper point out that,since agricultural tax was rescinded,the upper governments,such as town or country governments,whose political capacity to supply rural governance institution were weaken,in other words,they "quit" rural govern structure,leaving rural elites compete for the community common resources without regulatory system.Consequently,the probability and degree of conflict in rural election were significantly associated with the amount of rural collective common resources.The weakening of local governance capacity could be the root causes of conflict in rural election.As a result,if we want to change this situation,the local county township governments should be impelled to be more accountable towards rural governance.In addition,it is necessary to strengthen rural decision-making participation system mechanism.

There is a serious problem of human capital loss in current in the rural areas of China,and the present rural education system existence "depart from agriculture" tendency further intensifies the rural intelligence resources loss,form the so-called "education pump".Rural human capital shortage,which has a serious impact on China's socialist new rural construction goal the realization,and may cause further expansion between urban and rural areas.In view of this,the study focuses on China's rural areas to develop various "rural test "to promote the return of intellectual resources in rural areas,improve the stock of human capital in rural areas,summarize the experiences and lessons,and in contrast to rural education related model and experience at home and abroad on the basis,to promote the policy options available for reference.

In the face of multiple interests,organizational structures,cultures and thoughts emerging dur-ing China's social transition,corresponding social governance may learn from international practices and theo-ries in this regard;but at the same time it needs to take into account the uniqueness of China's social and eco-nomic structure and avoid applying them mechanically.In governing the pluralistic Chinese society,we should straighten out the relationship between the public and private sector,the state and society,and the government and market.We also need to effectively enhance our capacities for social governance by improving institution-ally in the long term,deepening public participation and supervision,making government decision-making and policy implementation more transparent and promoting cultural and ethical progress.

In the process of China's pursuit of industrialization,modernization and urbanization,rapid economic development and dramatic social transitions have led to hidden crises that went unnoticed for a long time.The authors point out that the root cause behind this is that the government lags behind in providing public goods and in ensuring development benefits are shared,social equity and justice is upheld,and cultural beliefs abound.To address the crises,this paper proposes establishing a fair and reasonable mechanism for allocating benefits from development,improving judicial and social systems,creating a mechanism for people to express their opinions and for their disputes to be handled through multiple channels,and actively including social forces in public affairs management,so as to eliminate such crises before they develop and spread.

Based on the life cycle model, this paper introduces average life expectancy, to test on the impact of life expectancy on China's household saving rate. Through collecting a provincial panel data of China's 31provinces during 1990—2009, the result of the empirical studies indicates that the life expectancy had significant positive impacts on household saving rate in China. In the sample period, of the growth rate of China's household saving rate, there were 4.2 percentage points resulted from the increase of the life expectancy, contributing to 42.9% of the total growth rate of the household of the saving rate. The results of empirical study of this paper also indicates that the expected future income growth rate had weak negative effects on household saving rate, and the impacts of expected future income uncertainty and population dependency ratio can not pass the significant test.

In this paper,we have attempted,by means of a large-scale sample survey of villages in China's differentregions,to analyze and sum up the whole status quo of the social stability and its characteristics in China's ruralareas,with the emphasis on the group of people "ignored" in the existing researches and on the possible existence of hidden perils.By the results of our study,we have discovered that,as a whole,China' rural society is stable,less conflicts have happened,their scales are small and the degree of their sharpness is low,however,the huge popular base in China's rural areas determines that the absolute number of clashes is not as small as we hope,even if their proportion is small.On the other hand,if the accumulated large amount of strong resentment in the rural areas can not be softened,it will cause great difficulties in the future maintenance of social stability.By the results of our study,we have also found that,in the system in which the governments on the grass root level get involved in the conflicts or resolve disputes,these governments,at present,have not played the proper role as they should,and that,sometimes,some improper measures of the maintenance of social stability may intensify the contradictions.Therefore,the improvement of the way of social management and paying close attention to the actual need of the most residents in the rural areas have great significances to safeguarding the social stability in China's villages

Conflicts in rural areas result from problems in grassroots management.When the governing capacity of grassroots government become weakened and cannot offer public service for farmers,or farmers' interest is directly encroached due to the combination with capital,contradictions are likely to happen and conflicts are likely to activate.To achieve good grassroots governance,functions of grassroots government departments should be transformed,asymmetric phenomena of ownership of properties and office power should be readjusted,evaluation forms for grassroots cadres and ways of solving rural debts should be reformed,thus to make the grassroots government serve the people and construct conflict resolving mechanism which is good for social stability.

在我国城乡"二元"结构的社会经济体制下,农村智力资源单方面流向城市,造成农村人才凋敝而城市人力资源结构性过剩的现状。"大学生村官"计划作为促进智力资源回流农村的重要试验,在进展过程中产生了一定效果,但仍然存在较大的困难和争议。从全国"大学生村官"计划的历程和各地模式中的经验教训来看,要使"大学生村官"真正有用于民,政府除了为大学生提供优厚待遇,进行项目、资金等支持外,更应该建立"大学生村官"计划实施的长效机制。