新能源汽车补贴政策工具挖掘及量化评价

现阶段中国大力开展新能源汽车示范推广工作,中央及各地方政府已相继出台一系列补贴政策。在严厉打击新能源汽车"骗补"及补贴政策重新调整等背景下,分析梳理现有政策从而对其进行整体把握与正确判断显得尤为重要,从而为政策改进与优化做准备。本文选取了截至2016年底国家和北京市颁布的涉及新能源汽车补贴的相关政策。首先,从采用文本挖掘的方法整理出的政策文本的高频有效关键词从中提炼出的政策工具,可分为供给型、需求型、环境型三类,分别从技术推动、市场拉动和环境支撑三个方面促进和规范新能源汽车市场。发现现有政策工具仍存在一些问题,如缺乏支持新能源汽车技术提升和产品开发的供给型政策工具;环境型政策工具的作用重点欠科学,对充电基础设施建设的重视程度不够;补贴过于聚焦新能源汽车购买环节等。其次,结合政策特点运用PMC指数模型构建了新能源汽车补贴政策的量化评价框架,通过变量分类、参数识别建立了多投入产出表,并通过PMC指数的测量、PMC曲面的生成综合反映政策各维度的情况。再次,采用实证分析的方法,选取3项新能源汽车补贴政策(P1、P2、P3)为研究对象,对政策进行量化评价。结果得出3项政策的PMC指数分别为7.52、6.95、6.21,均在良好的等级之内,P1政策的量化结果为优秀,P2、P3政策结果为良好,且具有较大的提升空间,可考虑在激励措施等方面予以加强。最后,根据新能源汽车补贴政策无法取得预期效果的原因,提出三点政策优化意见:(1)重视供给型政策工具的使用,加大新能源汽车科研资金投入;(2)环境型政策工具的作用重点应放在充电等基础设施的建设上;(3)需求型可考虑采取以公共交通带动私人交通的策略。     

Tree Basal Growth Response to Flooding in a Bottomland Hardwood Forest in Central Ohio1

Abstract: Tree basal growth in response to flooding regime was evaluated at a 5.2‐ha bottomland forest along the Olentangy River in central Ohio. Tree‐ring analysis was used to develop a 14‐year basal area increment (BAI) (cm²/year) series for 42 canopy trees (representing 10 species) throughout the bottomland. Mean annual BAI was evaluated relative to the frequency and duration of bankfull (>70 m³/s) and high‐flood (>154 m³/s) river discharge for a given water year (October 1‐September 30) and growing season (April 1‐September 30). A significant polynomial relationship was detected between the number of days of high‐flood river discharge over a combined two‐year period (Year i + Year i ? 1) and mean annual BAI. No significant relationships were detected when only the concurrent‐year or previous‐year flood regimes were considered or when growing season was considered. A similar relationship was detected when duration of high‐flood discharge days and BAI were both evaluated in two‐year increments (Year i + Year i ? 1). Mean annual BAI was most influenced by boxelder (Acer negundo) which was the dominant species and exhibited strong agreement with the overall BAI series. In each case, the resulting parabolic curve of tree basal growth in response to flooding suggests an optimal number of flooding days, a response to perturbation consistent with the subsidy‐stress model. Dendrochronology may be a useful tool for managers looking to restore environmental flows to regulated rivers.     

Application of optimal harvesting decision model to the analysis of Chinese forestry economic policy

This paper firstly extends the single period forest optimal harvesting decision model to infinite periods,in order to indicate how to determine the optimal rotation period aimed at maximizing forest revenue in all directions when repeat planting and harvesting trees on the same plot of earth till infinite future.The study also analyzes the influence of discounted rates,timber price,harvesting costs,planting costs,and tax on the determination of optimal rotation period;and how the optimal rotation period will change when we introduce the factors of continuously rising timber price and ecological revenue.Secondly,the authors introduce the intergenerational equity principle into the above model to design a resource-exploiting mode which satisfies bom the dynamic efficiency principle and the intergenerational equity principle.Last but not least,the research applies the above model to the analysis of Chinese forestry economic policy and explains the economic theory of institutions such as Government Purchasing Ecological Forest,Tree Compensation,and Forestry Subsidization,which provides a necessary theoretical foundation for future application of these new institutions.Besides,in regard to mis theoretical framework,the authors analyze the necessity of the Natural Forest Protection and Grain for Green projects which are currently being implemented in China.We also point out the emphasis of work to insure the project sustainable and successful.Finally,the research discusses the enterprise’s incentive to over-the-quota harvesting and the government’s means of restricting such behavior,which highlights the fact mat improved supervision and higher penalties are helpful in restricting over-the-quota harvesting.     

Theory and Model of Agricultural Insurance Subsidy

Abstract

The issue of agricultural insurance subsidy is discussed in this paper aiming to make it provided more rationally and scientifically. It is started with the connection between agricultural insurance and financial subsidy. It is really necessary and crucial to implement the financial insurance due to the bad operational performance, especially in the developing countries. But the subsidy should be provided more rationally because financial subsidy has lots of negative effects. A model in competitive insurance markets developed by Ahsan et al (1982) and a farmers' decision model are developed to solve the optimal subsidized rate. Finally, the equation is got to calculate it. But a quantitative subsidized rate is not made here because the calculation should be under some restricted conditions, which are always absent in the developing countries. So the government should provide some subsidy for the ex ante research and preparation to get the scientific probability and premium rate.