荷兰农业绿色转型经验与政策启示

[目的]与我国的农业资源禀赋条件相似,荷兰人多地少,农业资源贫乏,却是世界农业强国,其20世纪80年代开始的农业转型之路对促进我国当前农业绿色发展具有重要借鉴意义。[方法]结合实地调研与文献研究,文章梳理了荷兰40年来在农业环境治理方面的具体政策设计和实施效果,并分析了其主要经验做法及对我国发展的启示。[结果]从畜禽养殖数量控制到化学投入品控制、再到农业资源全管理,荷兰始终坚持以种养结合的可持续发展模式应对农业资源环境挑战,不断强化循环利用技术推广应用,逐步建立了严格的农业资源环境监管体系和政府支持体系,在农业污染得到有效治理的同时,依然很好地保持了国际市场竞争力。[结论]荷兰曾经面对的养殖业污染、化学品过度投入等问题也是我国当前农业环境的突出问题,其当时采取的转型思路与我们目前的绿色发展理念高度一致,借鉴荷兰经验,加快推进我国农业绿色发展,亟需创新循环农业发展模式,加强绿色发展技术支撑,建立并完善农业绿色发展制度体系,协同推进农业资源环境保护和农业竞争力提升。     

Assessing effects of federal crop insurance supply on acreage and yield of specialty crops

Crop insurance may affect harvested acreage and yield by influencing producers’ behavior such as land allocation and input use. Although specialty crops are a major source of farm income, especially on the U.S. west coast, they have not received as much attention as field crops in previous empirical studies. This paper assesses the effect of moral hazard and adverse selection associated with the federal crop insurance program (FCIP) on the acreage and yield of major specialty crops in California. An econometric method that expands the switching regression model is developed to assess the effect. Results suggest that federal crop insurance can change specialty crop growers’ production responses to climate and soil conditions. The moral hazard effect tends to increase the acreage and yield of the specialty crops, whereas the adverse selection effect tends to have the opposite effect. The overall effect of the FCIP on acreage and yield of specialty crops is found to be moderate.     

明代地方官府赋役核算体系的早期发展

明洪武到弘治年间,州县官府的赋役管理从基本不依赖核算向需要且能够进行核算的状态转变。洪武、永乐时期,在官府体系内部,只有田赋被部分地纳入核算管理,其他赋役征发则完全或绝大部分无法计量,也没有计划性。宣德以降,地方官员吸收民间粮里阶层分担赋役负担的经验,在此基础上进行旨在“均平”的改革,以确保赋役的可持续征发。在探索均平之道的过程中,不同地方官员多采取量化赋役负担、预定征收计划、将派征对象标准化并进行摊派核算的方式。其中,田赋额等开始扮演摊派对象的角色。这开启了州县层面赋役征收核算体系的发展之路,也导致府、州、县与户、工等部及布政使司之间产生了赋役核算信息不对称,出现了二重会计结构。     

Budget impact analysis of niraparib and olaparib for maintenance treatment of platinum-sensitive,recurrent ovarian cancer in the US

Aims: This study aimed to evaluate the budget impact of niraparib and olaparib in patients with platinum-sensitive, recurrent ovarian cancer from a US third party payer perspective.

Materials and methods: A budget impact model was constructed to assess the additional per member per month (PMPM) costs associated with the introduction of niraparib and olaparib, two poly ADP-ribose polymerase ribose polymerase (PARP) inhibitors recently approved to be used in platinum-sensitive, recurrent ovarian cancer patients with and without a gBRCA mutation. The model assessed both pharmacy costs and medical costs. Pharmacy costs included adjusted drug costs, coinsurance, and dispensing fees. Medical costs included costs associated with disease monitoring and management of adverse events from the treatment. Epidemiological data from the literature were used to estimate the target population size. The analysis used 1-year time frame, and patients were assumed on treatment until disease progression or death. All costs were computed in 2017 USD. One-way sensitivity analyses were conducted to evaluate the model robustness.

Results: In a hypothetical plan of 1,000,000 members, 206 patients were estimated to be potential candidates for niraparib or olaparib maintenance treatment after applying all epidemiological parameters. At listed 30-day supply WAC prices of $14,750 for niraparib and $13,482 for olaparib, budget impacts of these two drugs were $0.169 PMPM and $0.156 PMPM, respectively, most of which were contributed by pharmacy costs. Sensitivity analyses suggested that assumptions around market share, platinum-sensitive rate after first treatment, and WAC prices affected results the most.

Limitations: In this model, it was assumed that adopting niraparib and olaparib would not affect utilization of existing medications. Also, the estimated clinical parameters from clinical trials could differ from real-world data.     

Remaking Shanghai: New Divisions in an Expanding Metropolis

This study of Shanghai analyzes the city's emerging patterns of residential settlement in 2010. Most previous research on China focused on central city patterns, but by 2010 urban development in major metropolitan areas was taking place predominantly in the suburbs. The analysis re‐examines and extends previous studies of the level of segregation by various key population characteristics, showing that the highest segregation is found in the suburban ring, where original villager residents are now joined by an influx of migrants from other regions and by intracity movers. We probe the sources of the segregation pattern in multivariate analyses at two scales—an innovative analysis at the level of individuals that shows how people's citizenship status, occupation and education affect the type of housing that they are able to live in, and jointly contribute to their location in the metropolitan area. We show that the patterns attributable to the market reform period mostly did not supplant the socialist urban structure, but rather used it as its foundation. Segregation today can be attributed less to current class inequality than to state policies in the distant and recent past that have determined when, where and for whom housing is built.     

Moral hazard and subsidized crop insurance

Along with adverse selection, moral hazard is one of the major hurdles that private and public insurance plans must contend with. Moral hazard occurs if risks are endogenous to a producer's behavior and if the insurer is unable to properly monitor the insured. We review the role of moral hazard in the US crop insurance program. We conduct an empirical analysis of one important aspect of the US crop insurance program—prevented planting. This provision provides indemnity payments if conditions are not suitable for planting. The program has been the subject of considerable controversy, especially during 2019, when the rate of claims is expected to be especially high. Because loss adjustors may encounter difficulties in assessing the weather conditions associated with prevented planting claims, the program is susceptible to moral hazard. We consider the extent to which prevented planting claims may be endogenous to prices. We find significant evidence of moral hazard. The likelihood of prevented planting claims increases as the expected market price decreases or as fertilizer costs increase for corn and soybeans in the Prairie Pothole Region and for grain sorghum and cotton in all states.     

企业主导创新社区用户参与和新产品创意产出的动态关联研究

基于用户视角研究企业主导创新社区用户参与和新产品创意产出的动态关系。在理论分析的基础上，利用方差分析实证检验新产品创意产出不同阶段用户参与的变化。以12个社区共2400名用户为研究对象的实证结果表明：伴随创意产出数量的阶段提升，用户参与广度和深度都逐渐提高；伴随创意产出质量的阶段提升，用户参与深度逐渐提高，而用户参与广度只在创意产出质量后半阶段有显著提高。研究结果对我国消费电子企业动态采取措施引导用户参与创新有一定指导意义。     

我国水稻产业供给侧结构性改革的思考

[目的]文章在供给侧改革视角下对水稻供需的结构性矛盾等方面进行梳理,分析基于供给侧改革战略的关键环节、实施路径和未来发展趋势,以期为制定我国水稻供给侧改革战略提供参考。[方法]采用文献分析法和调查研究法,从我国水稻生产供求结构、价格"天花板"和成本"地板"双重挤压、水稻生产的资源环境、市场调节等方面分析了我国水稻产业供给侧的现状和存在的问题;通过日本、泰国、中国五常大米政策特点和经验教训的启示,提出了我国水稻产业供给侧结构性改革的策略。[结果]在分析我国水稻产业供给侧现状的基础上,总结得出水稻产业供给侧改革措施:优化水稻产业空间和功能布局,以项目带动水稻产业结构调整,提高和优化稻米品种品质结构、审定标准向抗性优质专用水稻品种倾斜,因地制宜调减水稻生产面积,调整国家收储稻米标准,延长水稻全产业链等。[结论]加速我国水稻产业供给侧改革,能促进稻米产业结构快速升级,有效破解稻米产业的结构性矛盾,增强我国稻米产业可持续发展能力和国际竞争力。     

湖南省乡村建设水平评价及对景观的影响利弊

［目的］改善乡村人居环境，推动新农村建设，是全面建设小康社会的重要组成部分。［方法］从经济发展水平、生活质量水平、社会发展水平及生态发展状况等4个方面构建包括20个指标在内的评价体系，基于2007—2017年的统计数据，采用熵权法对湖南省乡村建设水平进行定量化测度。在此基础上，进一步阐述了乡村建设对乡村景观影响的利弊。［结果］湖南省乡村建设发展水平评价分值呈现显著的递增趋势，由2007年的0177提高到2017年的0692。其中经济发展水平、生活质量水平、社会发展水平均明显提升，但生态发展状况波动较大，虽近年来得到一定的控制，但仍是制约新农村建设的重要因素。新农村建设为乡村景观的规划提供了经济支持，改善了乡村景观基本硬件设施条件，乡村旅游产业的发展也丰富了乡村景观的形式内容，推动了乡村景观的建设，但也在一定程度上引发了对生态系统平衡的破坏和对乡村景观的蚕食。［结论］在新农村建设过程中，遵循生态理论，充分体现地域特色，科学合理地进行乡村景观规划对推动新农村建设水平的整体提升至关重要。     

价值链视角下科技人才分布对区域创新系统效率的影响

科技人才作为科技创新的主体，是区域创新系统的重要投入，其省际分布状况潜在影响着各区域创新效率。基于2009-2016年我国内地30个省级区域科技人才与研发面板数据，在创新价值链分解的基础上，分别考察科技人才数量与结构维度对区域创新系统三阶段效率的影响。结果发现：在数量维度下，科技人才分布规模对区域知识创新效率、专利创新效率有非线性倒U型影响，先后从人才聚集规模经济效应转向不经济效应;整体集中度提高即全国科技人才分布相对集中有助于提升各地区专利创新与产品创新效率;在结构维度下，科技人才队伍中女性与博士研发人员越来越高的比重对知识创新效率表现为负向影响作用。最后，结合新旧动能转换背景,提出积极发挥人才集聚正向效应的建议。inno[]rlzb[]rlzb[]czpz[]czpz[]cyjg[]cyjg[]dwkf[]dwkf〖BHDG1*3,WK7*3ZQ,WK6。9DWW〗