低碳试点政策对城市土地绿色利用的影响——基于双重差分模型的实证研究

研究目的：探究低碳试点政策对城市土地绿色利用的影响效应与内在机制，以期从环境政策的角度为城市土地绿色利用提供对策建议。研究方法：Super-SBM模型、双重差分模型。研究结果：低碳试点政策对试点城市的土地绿色利用效率具有显著的促进作用，在考虑地区与时间特征以及其他影响因素的情况下，该促进效应为1.16%。机制分析结果显示，首先，低碳试点政策的实施对于当地产业结构转型具有促进作用，并表现为第一、第三产业比重的上升和第二产业比重的下降；其次，低碳城市建设所引致的城市创新能力的增强，通过低碳技术研发与应用，对土地绿色利用效率具有提升效应。研究结论：应通过持续推进低碳试点政策改革、结合本地产业特征引导产业转型、鼓励技术引进与创新等措施促进我国城市土地资源的绿色高效利用。     

数字经济发展对城市土地绿色利用效率的影响 ——基于基础设施建设的调节效应分析

研究目的：基于2006—2020年285个地级市面板数据，探究数字经济发展如何影响城市土地绿色利用效率，以及基础设施建设在其中发挥的调节效应。研究方法：多期双重差分方法、三重差分方法与门槛模型。研究结果：（1)数字经济发展对城市土地绿色利用效率具有显著促进作用。（2)这种促进作用存在明显的区域异质性和批次异质性，数字经济发展对中部地区和第二批试点的城市土地绿色利用效率提升影响更为显著。（3)当前，基础设施建设对数字经济发展和城市土地绿色利用效率主要呈负向调节效应，信息基础设施建设负向影响最大，交通基础设施建设次之，能源基础设施建设最末。（4)基础设施建设对数字经济发展和城市土地绿色利用效率的调节效应具有“由边际效益递增到边际效益递减”的单门槛非线性特征。研究结论：促进具有技术嵌入和环境赋能作用的数字经济发展，对提升中国城市土地绿色利用效率具有重要意义；基础设施建设作为数字经济发展的重要基础，其水平提升和效益转化还有待重视和加强。     

低碳试点城市政策与绿色经济增长——基于低碳试点政策的准自然试验

基于中国2003—2016年200个地级市的面板数据,利用双重差分方法评估了低碳试点政策对城市绿色经济增长的影响,并利用中介效应模型进一步进行了检验。结果显示,低碳试点政策显著促进了城市绿色经济增长;中介效应检验表明低碳试点政策通过技术创新、产业结构优化、市场化水平提升等促进了绿色经济增长。     

环保考核、政府环境注意力与城市土地绿色利用效率

研究目的：利用全国284个地级及以上城市2003—2019年的相关数据，从晋升考核视角出发，揭示环保考核对城市土地绿色利用效率的影响效应及其作用机理。研究方法：超效率SBM模型，Tobit面板回归模型，中介效应模型。研究结果：环保考核能提高区域内的城市土地绿色利用效率，并通过了一系列稳健性检验。中介效应检验结果表明，环保考核通过加强政府环境注意力提高了城市土地绿色利用效率。异质性分析结果表明，东中西部地区的环保考核政策均能提高区域内的城市土地绿色利用效率，中部地区的促进作用最显著。研究结论：中央政府应从激励、惩罚、促进竞争三个方面着手，在充分考虑区域异质性的前提下完善环保考核政策，有效增强地方政府环境注意力，提高我国城市土地绿色利用效率。     

工业用地错配如何影响区域绿色发展

研究目的：理论分析工业用地错配对区域绿色发展的影响机理,以期为优化工业用地配置进而促进绿色高质量发展提供科学的政策指导。研究方法：固定效应模型与系统广义矩模型。研究结果：（1）工业用地错配对区域绿色发展产生的影响具有时间上的滞后性和持续性;（2）工业用地供给规模失衡,将挤占居住用地供应,抑制绿色技术创新,阻碍产业结构升级,而不利于区域绿色发展;（3）工业用地供给方式失当,会使得大量低质企业被引进,短期内带来巨大投资而促进GDP增长,但会损害长期的经济发展效益,同时造成愈发严重的环境污染问题,而阻碍区域绿色发展。研究结论：未来应改革政府政绩考核体制与财税体制;制定规范、灵活的供地方式与标准,提高工业用地配置与利用效率;优化土地供给结构,引导产业结构升级,发挥市场对工业用地配置的决定性作用。     

数字经济发展对工业用地利用效率的影响——基于国家级大数据综合试验区的准自然实验

研究目的：以中国实施的国家级大数据综合试验区政策为准自然实验,探究数字经济发展对工业用地利用效率的影响及作用机制,以期为推动工业用地资源优化配置与数字经济政策体系创新提供参考。研究方法：SuperSBM-Undesirable模型、多期双重差分模型。研究结果：（1）研究期内,数字经济发展能够显著提升工业用地利用效率。（2）企业技术创新和工业转型升级在数字经济发展影响工业用地利用效率的过程中起到中介作用。（3）数字经济发展对工业用地利用效率的提升作用具有明显的异质性,其中,在中西部地区和非资源型城市显著为正,在东部地区和资源型城市不显著。研究结论：应充分发挥数字经济发展赋能企业技术创新和工业转型升级的积极作用,因地制宜地推进数字经济政策创新,促进工业用地提质增效,实现数字经济与实体经济深度融合发展。     

绿色技术创新视角下数字经济对城市绿色全要素生产率的影响研究

绿色是可持续发展的底色。在建设数字中国的背景下，基于数字基础设施和数字金融的数字经济是否对城市绿色全要素生产率起到了促进作用？其影响效果和路径值得进一步探讨。文章从绿色技术创新视角出发，基于2011—2019年280个地级市的面板数据，测算了城市绿色全要素生产率，使用固定效应模型、门槛模型和中介效应模型，实证检验了绿色技术创新视角下数字经济对城市绿色全要素生产率的影响。研究发现：（1）数字经济和绿色技术创新均能够提升城市绿色全要素生产率，在使用工具变量与双重差分DID后，结论依旧成立。（2）绿色技术创新存在单一门槛值，高水平绿色技术创新驱动显著增强了数字经济对绿色全要素生产率的促进作用。（3）绿色技术创新作为数字经济提升绿色全要素生产率的重要路径，存在中介效应，且高强度绿色技术创新对绿色全要素生产率的中介效应更优。（4）区分城市规模来看，数字经济通过绿色技术创新的中介效应仅促进了大型、中型、小型城市的绿色全要素生产率提升。因此，推动城市绿色全要素生产率需要全方位提升数字经济发展规模，构建绿色创新研发体系，根据城市特点合理规划我国城市绿色转型升级路径。     

科技金融政策改善了城市空气污染吗？——基于“促进科技和金融结合试点”的准自然实验

创新是城市发展的第一动力，绿色是城市发展的内在要求。科技金融政策通过金融手段助力创新发展，对城市绿色发展具有重要意义。文章基于2004—2020年中国284个城市的面板数据，采用多期双重差分法评估了科技金融政策对于城市空气污染的影响。研究结论如下：（1）试点政策显著抑制了城市工业二氧化硫排放和工业烟（粉）尘排放，且随着政策不断推进，该抑制效应呈现增强态势；（2）科技和金融结合试点政策通过提高地区绿色技术创新水平和推动产业结构升级的双重路径改善城市空气污染；（3）科技金融政策对空气污染的抑制作用因城市的地理区位、人口规模、科技投入和金融发展水平的不同而存在差异。研究认为应根据不同地区禀赋条件，完善地区科技金融体系建设，强化科技金融治理，推动科技企业发展；走绿色发展道路，重视科技创新发展的同时加强对传统行业的环境友好化改造。     

专利保险试点政策能否促进地区全要素生产率提高？

文章利用专利保险试点政策这一准自然实验,采用2004—2019年地级及以上城市面板数据,建立双重差分模型（DID）,研究专利保险试点政策究竟如何影响地区全要素生产率。研究发现,专利保险试点政策能够显著促进地区全要素生产率提高;机制检验发现,专利保险试点政策能够通过创新激励效应、产业结构升级效应促进地区全要素生产率提高;异质性分析发现,专利保险试点政策提高全要素生产率的政策效果在东部地区、经济规模大、金融发展程度高、人才集聚程度高的地区更加明显。为此,文章从扩大专利保险试点范围、促进技术创新和产业升级、因地制宜推行试点政策等方面提出相应的政策建议,为今后推动经济高质量发展提供了积极启示。     

中国碳市场交易价格的共同趋势特征研究

以碳交易价格为研究对象,利用2013年6月至2019年3月中国8个碳试点市场的碳交易价格数据,采用面板协整检验方法,从统一整合的视角挖掘国内碳交易价格的共同趋势特征。结果表明:在5%显著水平下,2或3个碳试点市场间的共同趋势特征较明显;4或5个碳试点市场间有一定的共同趋势特征;6个及以上碳试点市场间没有共同趋势。尽管8个碳试点市场交易价格差异较大,但是在全国碳市场统一趋势下,整体兼容性存在很大的改善空间。因此,为实现中国碳市场的衔接统一需要推进配额分配方案建设。碳市场交易需要完善碳交易价格机制,丰富碳交易品种和交易方式。碳市场建设需要推进碳试点过渡,健全相关法律政策体系,从而促进全国碳市场衔接。     

Application of an ecosystem function framework to perceptions of community woodlands

Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

土地学科的建设和发展——"土地学科发展规划研讨会"综述

中国土地科学学科发展已取得很大成就,表现为专业教育和人才培养成绩突出、初步形成学科体系、取得大批研究成果.而存在的问题主要是基础理论研究欠缺、独特的土地科学研究方法体系尚未形成、研究角度单一、学术交流质量不高和学科带头人的影响力不足.土地科学学科发展目前面临着巨大的机遇和挑战,应明确土地科学学科发展的基本思路、发展目标及2010-2020年的主要建设任务和保障措施.     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.     

Evaluating Alternative Policy Responses to Higher World Food Prices: The Case of Increasing Rice Prices in Madagascar

Higher world food prices have led many developing countries to adopt policies to mitigate the impact on low-income households. This article sets out a partial equilibrium framework to evaluate the efficiency, distributional, and revenue implications of alternative policy responses. The model is applied to evaluate tariff reductions and targeted transfers in Madagascar. Although lowering tariffs generates substantial efficiency gains, these accrue mainly to the top half of the welfare distribution, and poor net sellers are actually worse off. Developing a system of targeted direct transfers to poor households is likely to be a substantially more cost-effective approach to poverty alleviation.     

Agrarian Poverty,Nutrition and Economic Class – A Study of Gujarat,India

This paper analyses poverty and calorific undernourishment in the Indian state of Gujarat, where high and market‐led industrial growth has resulted in rapid economic improvement. The study is carried out through a combination of secondary and survey‐based data. We conclude that the neoliberal agenda of uncontrolled, outward‐looking growth has not resulted in significant reduction of poverty or malnourishment in rural areas. Furthermore, while land ownership is officially used as a proxy for wealth distribution, class position appears a better predictor of poverty status in the rural areas than landownership per se. At the policy level, there is a need to revive the agrarian economy and create new non‐agricultural assets, and the primary focus in the state must shift to the distribution of created assets rather than a single‐minded focus on growth.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

Transaction Cost Thresholds in International Rice Markets

Recent episodes of high and volatile prices for grains such as rice have raised concerns about their implications for hunger and poverty. We model price relationships between international rice prices and 221 domestic prices in 47 developing countries that import rice. We use a threshold vector error correction model that accounts for transaction costs of trade in spatial price transmission, and an improved regularised Bayesian threshold estimator for threshold models. Our results show that threshold values are higher after 2008 than before, which suggests that transaction costs in international rice trade have increased in recent years. Threshold values are highest for Latin American countries followed by African and Asian countries, and higher for retail than for wholesale prices. Since 2008, price transmission is slower in countries that responded to high and volatile prices with domestic market‐based interventions such as price controls and faster in countries that responded by lowering tariffs and by implementing production support measures.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

Does sustainable agricultural growth require a system of innovation? Evidence from Ghana and Burkina Faso

This paper tests the ‘systems of innovation’ hypothesis for a selection of crops in Ghana and Burkina Faso that have shown significant growth in production over an approximately 20-year period. The question is whether such growth can only occur if supported by a system of innovation. Using two indicators (a common understanding on objectives and priorities, and a high level of interactivity), we find little evidence for the existence of anything that might be considered a high functioning system of innovation.