Exploring the silvicultural and economic viability of gap cutting in Mediterranean softwood plantations

Gap cutting consists of the removal of all trees growing on a small surface, varying in size from 200 to 600 m2. In Italy, gap cutting has been successfully tested for introducing the natural regeneration of native species into softwood plantations, thus ac- celerating the transition towards climax hardwood stands. Depending on plantation types and conditions, gap cutting should be start- ed at an age between 70 and 80 years and the system should include at least 12 to 15 gaps, in order to produce enough wood to cover costs. Generally, natural regeneration is firmly established within 5-7 years from treatment. Gap cutting also offers superior results to selection thinning, the latter producing about 35% less value and incurring 25% to 30% more costs. As for all regeneration cuts, the success of gap cutting depends on wildlife control in order to prevent extensive damage to the regeneration.

Sustainability Assessment of Banana (Musa spp.) Yield Gap Reduction through Value Chain Development Interventions in Smallholder Farming Systems in Manicaland, Zimbabwe

This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study used a mixed methods research design that relied on farmers records for the quantitative analysis and focus group discussion and in-depth interviews for key experts for the qualitative aspects. A mix of regression analysis, t-tests, Pearsons’s correlation and analysis of variance statistical methods were used for the quantitative analysis while thematic response analysis was used for the qualitative engagements. The findings showed that by the end of the activity, the project had successfully narrowed the banana yield gaps to 18.66 tons per hectare working with a potential yield base of 40 tons. However, 5 years after the project closure the yield gap had fallen to 24.7 tons indicating a lack of sustainability of yield gap reduction. However, the yield gap slump does not override the fact that farmers on average were still able to sell approximately 5 tons per every 6 months after 5 years from the project closure which is beyond any poverty threshold. This suggests genuine upward economic mobility. Additionally, in analyzing what factors had the greatest influence on yield gap reduction, the access to fertilizer ranked highest where genetics, irrigation and improved agronomy followed in that respective order. The study further showed that farmers who receive value chain development support whilst at an already commercialized state tend to maintain productivity thresholds higher in comparison to those who are at a pre commercial state. This is evidenced by the fact that the pre commercial farmers had a yield reduction of 30.83 percent after 5 years of the project closure whereas the former realized a productivity growth of 7.84%. In conclusion, whilst the intervention was successful in transitioning farmers out of poverty, more investment should be made towards transitioning smallholder farmers to integrated soil fertility management practices and improvement of agronomic efficiency through stronger on field collaboration between research institutions, the government and development institutions.

Technology Gaps, Resource Allocation and Economic Growth of Large Late-starting Countries

In the evolution of economic growth drivers, technology gaps are a key variable that determines the efficiency of resource allocation. Analysis of an optimal resource allocation path based on an extended endogenous growth model reveals that economic growth drivers evolve from productive investment to R＆D investment and a shift from imitation to innovation. Empirical analysis based on China＇s provincial-level panel data suggests that the effect of productive investment and R＆D investment, as well as innovation and imitation, on economic growth and technological progress varies greatly among regions of disparate technology levels. As a late-starting country, China should properly allocate resources between productive investment and R＆D investment, and between imitational investment and innovative investment while advancing the transformation of economic growth patterns on a differentiated basis in light of regional technology disparities.

Research on the Impact of Rural Labour Forces Transfer on the Urban-rural Income Based on Economics of Discrimination

On the basis of the analytical frame of discrimination, the thesis establishes a model of transfer of rural labour forces into city, and researches the impact of rural labour forces transfer on urban-rural income. The results show that the transfer of rural labour forces into city can increase urban-rural income and bridge the income gap between city and village to a certain extent. However, the capital stock of city in China is greatly more than that of the village, so the rural labour forces transfer cannot eliminate the urban-rural income gap completely. In order to elevate the rural income level in China and narrow urban-rural income gap, the government should paint a picture with two brushes at the same time: on one hand, the government should promote the transfer of rural labour forces into city, and change the status quo of dual urban-rural labour forces market structure; on the other hand, the government should increase the input in rural areas and promote the increase of rural capital stock so as to further increase rural residents' income in the process of labour forces transfer.

Wetland Economic Valuation Approaches and Prospects in China

Ecosystem services valuation seeks to increase the social relevance of ecosystem characteristics, the underlying biological mechanisms that support services, by making the contribution of ecosystems to human well-being explicit. Economic valuation can help management by clarifying the full range of benefits and costs of proposed management actions. In the past two decades, economic valuation of wetland ecosystem services has become one of the most significant scientific priorities for wetland protection. In this paper, we provide an overview of ecosystem services, and summarize the main interdisciplinary approaches to measure and value wetland ecosystem services. We identified four main methodological gaps preventing progress on wetland valuation of ecosystem services in China, which are: 1) confusion on terminology like intermediate and final ecosystem services, 2) lack of ecological production functions to link ecosystem characteristics to final ecosystem services, 3) static valuation making it difficult to evaluate the trade-offs and synergies among ecosystem services, and 4) lack of clear guidance on relating ecological compensation programs to conservation targets. Overcoming these gaps is important to inform wetland compensation mechanisms and conservation policies. We propose future research on wetland ecosystem services in China should be focused on: 1) defining final ecosystem services based on beneficiary preferences and underlying biophysical mechanisms, 2) establishing wetland monitoring programs at specific sites to collect data on final ecosystem service indicators and ecosystem characteristic metrics to create ecological production functions for economic valuation and rescaling techniques, and 3) incorporating wetland ecosystem service values into decision-making processes to inform wetland management.

Standards of Economic Growth to Apply Creative Projects

This study theoretically showed the importance of standards economic growth to apply creative projects to avoid loss cost and efforts. There is problem of complexity environment to understand real economic growth. Companies and government can affect economic. There is a need to make standards to control steps of economic growth as result to accounting gaps, economic gaps, and financial analysis gaps. Standards must face negative affection of speculation, government involving in economic, developing tool. Evaluating must be built up to real market price and also standards must build trust to support developing. Searcher recommended linking economic growth with real growth of producing and ways to get real market price to evaluate company assets, liabilities, and net profit after tax for all users as factors show growth in company to growth economic units which are successful by applying creative projects.

环境质量视角下收入差距对经济增长的影响研究——基于环境质量中介与门槛效应的实证分析

缩小收入差距,提升环境质量,实现经济可持续增长是推动我国新时期高质量发展的本质要求。基于2009—2020年中国30个省份的面板数据,运用动态面板模型、中介效应模型、动态门限面板模型实证研究了收入差距对经济增长的影响,以及环境质量在二者关系中所发挥的中介效应与门槛效应。研究结果表明:收入差距的扩大对经济增长有明显的抑制作用;环境质量在收入差距影响经济增长的过程中起到了部分中介作用与单重门槛效应,随着环境质量改善收入差距对经济增长呈现先促进后抑制的特征。政府应当积极通过缩小收入差距,优化环境质量与收入差距的匹配模式来促进经济增长,实现中国经济的可持续发展。

中国数字经济空间动态演进的区域现状

数字经济已成为引领我国经济一体化高质量发展的主要驱动力,立足于国家整体经济及区域经济稳步协调发展的战略。文章基于中国2013—2020年省级数据,运用主成分分析法对中国数字经济进行测度,并运用社会网络分析及核密度等方法对我国数字经济动态演化的空间关联及区域差异进行研究。研究发现:(1)2013—2020年我国数字经济发展整体网络密度稳步提升但依旧处于低水平。(2)中国各省份数字经济发展两极分化,东部与西北、东北等边缘地区存在“数字经济鸿沟”,加之整体关联水平低,分化严重,发达地区对边缘地区的辐射效应较低,差距可能愈发扩大。(3)将其划分为四个板块,发现存在“弱关联”板块,板块间溢出关系及关联度差异悬殊,进一步研究各省份数字经济发展的“中间人”作用,发现各省份承担角色更是“极化”严重。研究结果可为我国持续深化数字经济建设,推动经济协调、稳定、高质量发展提供参考。

数字经济、创新差距和中心-外围城市经济差距——基于新经济地理的视角

采用新经济地理模型,基于数字经济的空间知识溢出效应,推演出数字经济对经济地理格局的重塑机制。该模型表明,数字经济通过改变城市创新差距,重塑了区域经济空间结构。利用2005—2022年我国237个地级市的面板数据,采用时间和区域双重固定效应模型进行实证检验。结果显示,数字经济有助于缩小外围城市与对应中心城市的经济差距。机制检验表明,数字经济显著降低了城市创新差距,从而有利于缩小中心-外围城市的经济差距。此外,异质性分析表明,与对应中心城市地理距离越远的外围城市,数字经济发展对缩小其与中心城市经济差距的作用越大。基于研究结论,提出外围城市应加快数字经济发展、建立健全区域数字基础设施无障碍分享机制、深化区域数字要素市场一体化改革等政策建议。

碳减排与南北经济差距——基于量化空间模型的分析

中国于2020年联合国大会明确提出争取分别在2030年和2060年前实现碳达峰和碳中和。与此同时,中国发展经济和改善民生的任务艰巨,面临着区域经济发展分化态势明显的新情况和新问题。本文在Caliendo等(2018)构建的具有投入产出联系、人口流动的多地区、多部门一般均衡模型基础上引入二氧化碳排放,探究了碳减排对区域经济差异(包括八大经济区、南北地区经济差距)的影响,以及全国碳交易市场建立在其中的调节作用。研究结果显示,按照目前的生产率增长速度,①若不存在全国性碳交易市场,碳减排会抑制发达地区的经济发展,从而缩小南北经济差距;②碳排放交易市场的建立在通过碳价格一体化实现碳从低效率地区向高效率地区转移,从而提高碳资源配置效率的同时,也会加剧地区间的收入差距问题,南北经济差距增大。因此,在碳减排目标实现的过程中,需要同时结合中央财政转移支付手段以解决区域发展不平衡问题,缩小此过程中伴随增大的南北经济差距。

数字金融发展扩大区域绿色发展差距了吗

基于2012—2019年中国285个城市的面板数据,利用EBM-GML指数和空间杜宾模型实证考察数字金融发展对绿色经济效率及绿色发展差距的经济效应、异质特征和传导渠道。研究发现:数字金融与绿色经济效率之间呈U形关系;数字金融发展会拉大群际绿色发展差距,加剧绿色发展不平等;数字金融的三个子维度和不同城市等级对城市绿色经济效率的影响存在异质性;绿色技术创新和产业结构升级是数字金融影响绿色经济效率的主要路径,而绿色技术创新和地区创业水平的差异是绿色发展差距扩大的主要原因。

低碳转型能否推动区域协调发展?——来自“低碳城市”建设的经验证据

实施区域协调发展战略是实现共同富裕,推进中国式现代化的关键路径。基于2006-2019年中国243个地级及以上城市的面板数据,运用双重差分法系统考察了低碳转型对区域协调发展的影响及其作用机制,研究发现:低碳城市建设能显著缩小非中心城市与中心城市的经济差距,而且对于整体发展水平较低、工业依赖型和距离中心城市较近的城市,在缩小与中心城市的经济差距方面有更明显的影响。低碳城市建设缩小区域经济差距的主要传导机制来自城市产业低碳转型、技术创新能力的增强与人力资本的流入。这意味着低碳转型有助于实现“碳中和”与区域协调发展的“双赢”目标。为统筹推进绿色低碳发展和共同富裕,要建立绿色低碳转型的区域协作机制,加快产业绿色低碳升级改造,以低碳转型为契机加强人才引进等。

农产品流通数字化能否提高农业经济韧性

流通是生产和消费间的重要纽带,农产品流通数字化促进生产、流通、消费的良性循环。文章基于2012—2021年省级面板数据,运用空间杜宾模型实证研究了农产品流通数字化对农业经济韧性的影响。结果表明:农产品流通数字化能够显著提高农业经济韧性并具有明显的正向空间溢出效应;城乡收入差距在农产品流通数字化影响农业经济韧性机制中发挥了负向调节作用;异质性分析发现农产品流通数字化对农业经济韧性的影响和空间溢出效应在东部地区和粮食主销区更加显著。政府应完善数字基础设施建设、加快农产品流通数字化转型,促进城乡整合发展、缩小城乡收入差距,协调省际流通资源布局、增强协同联动效应,为提升农业经济韧性创造良好环境。

普惠金融对经济增长与城乡收入差距的影响

为考察普惠金融对经济增长与城乡收入差距的影响,文章选取2013—2020年我国31个省份的面板数据,通过纳入债券、股票等直接融资工具指标构建普惠金融指数,并利用静态面板可行广义最小二乘回归模型、动态面板广义矩回归模型,研究全国以及东、中、西部地区普惠金融发展水平对经济增长与城乡收入差距的影响。结果表明:总体来看,普惠金融与经济增长存在“U”型关系,普惠金融与城乡收入差距存在“倒U”型关系。分地区来看,普惠金融对经济增长与城乡收入差距的影响均表现出一定程度的区域异质性。

高铁建设、知识溢出与区域创新差距

本文构建了包含旅行时间成本和商品贸易成本的新经济地理学模型,阐释了高铁促进知识溢出进而影响区域创新差距的作用机理,并进行实证检验。在商品贸易成本既定的情况下,压缩旅行时间可能会加剧创新要素的空间集聚,但高铁的知识溢出效应可能会缩小区域创新差距。实证结果表明,高铁显著提升区域创新绩效,但同时也拉大了高铁城市之间的组内创新差距,使之成为区域创新总体差距的主要来源。分区域看,高铁在中西部拉大了高铁城市组内的创新差距,而在东部却缩小了组内创新差距对整体差距的贡献;高铁主要加大了中小城市对区域创新差距的贡献程度。此外,降低商品贸易成本会强化高铁对区域创新的影响,不同类型交通基础设施对区域创新呈现出协同作用。研究结论对于高铁网络下提高创新资源配置效率、促进区域协调发展以及在全国统一大市场背景下协同推进区域之间商品和创新要素一体化具有启示意义。

统一大市场、产业结构调整与区域经济差距

缩小区域经济差距是我国实现共同富裕总体目标的重要内容,全国统一大市场建设对于我国区域产业结构调整、缩小区域经济差距、实现共同富裕具有重要影响。文章利用我国2011—2020年省级面板数据,基于产业结构调整视角,探讨了统一大市场对我国区域经济差距的影响效应及作用路径,研究发现:整体而言,统一大市场可显著缩小区域经济差距,但由于集聚效应与分散效应大小的相对变化,统一商品市场与要素市场对我国区域经济差距影响存在“倒U型”效应,且当前我国大约1/3的省份已跃过拐点,经过一系列稳健性检验并消除内生性问题后,该结论依然成立;深化区域产业分工和促进区域产业结构升级在统一大市场影响区域经济差距中发挥重要中介作用,商品市场和要素市场统一有利于区域产业分工和产业结构升级并存在互补效应,且能相互增强其对区域经济差距的影响。基于此,文章从完善统一大市场建设、优化区域产业结构调整等方面提出政策建议。

市场分割与地区经济发展差距:影响路径与实证检验

市场分割是导致我国区域经济发展不平衡的重要影响因素,文章基于2005—2019年中国9个城市群140个城市的数据,实证分析了市场分割对地区经济发展差距的影响机制,并通过多重中介效应模型实证检验其影响路径。研究表明:各城市群地区经济发展差距与市场分割具有较大差异;市场分割与地区经济发展差距存在“U”型关系,即较低程度的市场分割能够缩小地区经济发展差距,而较高程度的市场分割则会扩大地区经济发展差距;进一步检验其中介渠道发现,市场规模和市场竞争是市场分割影响地区经济发展差距的重要中介渠道,且市场规模的影响更为显著;中心与非中心城市市场分割对地区经济发展差距的影响存在差异,中心城市较低程度的市场分割并未带来地区经济发展差距的缩小。

新型基础设施投资对区域经济差距的影响

从新型基础设施角度出发采用动态面板的研究方法,以中国2003—2020年30个省份为样本,探讨新型基础设施投资对区域经济差距的影响。研究结果表明:新型基础设施投资与区域经济差距呈倒“U”型关系,这一结果经过一系列的稳健性检验后仍然成立;进一步分析表明,新型基础设施投资会缩小东部地区经济差距,但是会扩大中部、西部地区经济差距;将新型基础设施分为融合基础设施、信息基础设施、创新基础设施后,发现融合基础设施对于区域经济差距的扩大效应弱于信息基础设施、创新基础设施;新型基础设施投资会通过劳动效率、技术创新渠道影响区域经济差距。

培育数字素养的价值与路径:基于农村共同富裕的分析

促进农村居民共享数字红利,以人的知识与技能现代化,缩小不同群体间收入差距,是推进共同富裕与中国式现代化发展的重要内容。在三维资本的理论框架下,分析公众数字素养作用于农村收入分配的机制,并基于CFPS2014、CFPS2016、CFPS2018、CFPS2020年四期调查数据进行了实证检验,得出:①培育数字素养能显著缩小农村收入差距、促进农村共同富裕。②个体经济、文化与社会资本是数字素养作用于农村家庭收入差距的重要渠道,而以上三个渠道畅通的关键在于数字素养的要素收入与劳动技能提升效应以及社会网络和信任关系增强效应。③致富动力、数字习得意识以及素养培育外围环境均会作用于数字素养的价值层,进而约束数字技能与知识水平,从而在促进共同富裕方面表现出异质性效应:当家庭抚养负担重或依赖农业生产时,致富动力较强,培育数字素养对优化收入分配格局的价值更大,从而有利于促进农村共同富裕;增强个体数字习得意识能有效提升个体数字技能,进而增强培育数字素养在促进共同富裕方面的正向价值;优化治理能力体现的软环境与数据技术发展的硬环境,能进一步激发数字素养培育的共同富裕促进效应。以上结论显现了培育数字素养的价值,从人的知识与技能现代化发展视角,探索了缩小收入差距的可行方案,既回应了自由主义与凯恩斯主义实现“库茨涅兹拐点”的争论,又呼应了中国式现代化与共同富裕的战略要求。

经济增长压力下“能耗双控”政策会加剧绿色全要素生产率南北分化吗?

严格的环境规制会倒逼北方地区通过提升绿色全要素生产率缩小南北差距,还是诱发了经济增长压力下地方政府的保增长动机,反向加剧了南北方地区的绿色发展差距?文章使用地级市数据细化分析精度,并以2011年制定的“能耗双控”政策为冲击,使用双重差分法探究了“一刀切”式的环境规制政策对于区域协调发展与绿色转型的影响。文章研究发现,“能耗双控”政策实施后,南北方地区间的绿色全要素生产率差距显著扩大,并且经济增长压力的上升会进一步加剧这种分化趋势,不利于区域协调发展。在此基础上,文章从产业结构调整和技术进步两个视角进行了机制分析,结果表明政策实施后,产业结构高级化、高技术产品出口技术复杂度和绿色创新的分化是导致南北方地区绿色全要素生产率差距扩大的重要因素。经济增长压力的存在会通过放大南北方地区在产业结构与技术进步方面的差异,引致南北方地区间绿色全要素生产率差距的进一步扩大。文章的研究结论为“双碳”目标下环境规制政策的制定和实施提供了经验证据,基于不同地区差异化的资源禀赋和发展基础制定因地制宜的发展政策,更有利于区域经济绿色转型和协调发展。