The Ban on Illegal Mining in Ghana: Environmental and Socio-Economic Effect on Local Communities

The study was conducted to assess the effects of small-scale (artisanal) gold mining and its social and economic implications on the people in Amansie West District of Ghana. The artisanal gold mining communities were studied using secondary data from scholarly articles and journals, books, conference papers, research reports, policy documents, working papers, and briefs. Descriptive and systematic analyses were conducted. The result indicated that youth aged between 21 - 30 were most likely to engage in illegal mining operations in the selected study areas. The study revealed that farmland had been destroyed, making farming difficult for the inhabitants. It is evident from the review that dug-out pits from mining serve as breeding grounds for mosquitoes and death traps for humans. The study, therefore, accentuates the need for illegal small-scale gold mining to be formalised and strategic interventions and policies proposed for the protection of Ghana’s Natural resources. Furthermore, community members should be involved in policy-making and environmental protection issues to help control the menace of landscape destruction. Although the ban on illegal gold mining activity by the government has caused more people to lose their jobs leading to livelihood challenges in mining communities, it is a step in the right direction, as the ban seeks to halt and check the illegal small-scale mining sector. The study recommended alternative livelihood and income-generating projects such as beekeeping, mushroom culture, grasscutter rearing, and agroforestry technologies including the growth of economic fruit trees as alternative livelihood ventures.

A Note on an Economic Lot-sizing Problem with Perishable Inventory and Economies of Scale Costs:Approximation Solutions and Worst Case Analysis

This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several properties of the optimal solutions are explored. With the help of these optimality properties, a polynomial time approximation algorithm is developed by a new method. The new method adopts a shift technique to obtain a feasible solution of subproblem and takes the optimal solution of the subproblem as an approximation solution of our problem. The worst case performance for the approximation algorithm is proven to be （4√2 ＋ 5）/7. Finally, an instance illustrates that the bound is tight.

Assessment of Stress Cognitive Control and Executive Function with Stress Control Rating Scale (ECOSTRESS) and Low Resolution Brain Electromagnetic Tomography (LORETA) (In Portuguese People in Situations of Unemployment and Economic Insufficiency)

This article reviews the constructs of stress, appraisal, coping, according to a transactional perspective, and executive function, and presents a stress control rating scale (ECOSTRESS), which design is founded in these constructs. This psychometric tool is useful in the assessment of cognitive control of stress, correlated with the function of dorsolateral prefrontal cortex. It has been validated for its use in the assessment of Portuguese people in situations of stress related to unemployment and economic insufficiency. Also, within the context of the cognitive control of stress, it is highlighted the usefulness of low resolution brain electromagnetic tomography (LORETA).

Socio-Economic Characteristics of Three Artisanal Fisheries Communities in the Northern Sudanese Red Sea Coast

Socio-economic characteristics related to fishing gears and boats from three selected small-scale fishers’ communities (Oseif, Dungonab and Mohammed Qol) in the northern part of the Sudanese Red Sea coast were studied. The study was designed to provide base line data and information on the current socio-economic situation, factors that determine the use of fishing gear, types of boats and fishing equipment, challenges facing fishers and the extent to which fishing gear and boats are related with the socio-economic characteristics of the fishers community in the study sites. Fieldwork was carried out during 2016. The study methods included a series of interviews based on questionnaires, field observations and focus group discussions. The results of the study showed that the most common fishing gears are handlines, cast nets and gillnets. The two types of boats used at the study sites are motorized fiberglass and houri (motorized and paddled) with a V-shaped hull. Boat ownership varies among fishers. Each fisher can have several types of gears in different numbers. Target fish species, season, efficiency of gear and fishing location were the main factors determining the use of fishing gear at study sites, respectively. All fishers are men and most have families of at least four people. The majority of fishers are between 21 and 50 years old and work mainly in fishing. They inherited fishing knowledge within the family, and most of them have been working in artisanal fishing for more than 10 years. Fishers have relatively good net incomes compared to other government employers in the study sites. Most fishers work full time in fishing. A small number of fishers work part-time with the possibility of undertaking other income-generating activities such as animal husbandry and seasonal agriculture. The main challenges identified by fishers at the study sites were fish prices, sea surface roughness and high cost of fishing materials, respectively. Most fishers perceived a recent decline in both catch size and abundance.

Role of Accessibility and Socio-Economic Variables in Modelling Population Change at Varying Scale

During past decades, effects of accessibility to growth have been considered extensively. In previous studies, however, matter of scale has been largely ignored. In this study, relevance of travel accessibility and essential socio-economic variables for explaining population change analysed with a multi-scalar study setting by the case of Finland. The analytical framework of the study relies on applied geographical information systems (GIS). Relationships between population change and explanatory variables were established with non-linear multiple regression, generalised additive models (GAMs). The data consist of population and socio-economic grid cell databases based on authentic records, transport network models, including complete digital road network database. Models were established at six resolutions between 2 km × 2 km and 24 km × 24 km. The main result is that the performance of the models, explaining and predicting population change, strongly relies on potential accessibility particularly at accurate resolutions. An important finding is also that it is possible to establish explain and predict population change tolerably at accurate resolutions and well at coarse resolutions, as the performance of models increases with scale.

Data envelopment analysis for scale elasticity measurement in the stochastic case:with an application to Indian banking

In the nonparametric data envelopment analysis literature,scale elasticity is evaluated in two alternative ways:using either the technical efficiency model or the cost efficiency model.This evaluation becomes problematic in several situations,for example(a)when input proportions change in the long run,(b)when inputs are heterogeneous,and(c)when firms face ex-ante price uncertainty in making their production decisions.To address these situations,a scale elasticity evaluation was performed using a value-based cost efficiency model.However,this alternative value-based scale elasticity evaluation is sensitive to the uncertainty and variability underlying input and output data.Therefore,in this study,we introduce a stochastic cost-efficiency model based on chance-constrained programming to develop a value-based measure of the scale elasticity of firms facing data uncertainty.An illustrative empirical application to the Indian banking industry comprising 71 banks for eight years(1998–2005)was made to compare inferences about their efficiency and scale properties.The key findings are as follows:First,both the deterministic model and our proposed stochastic model yield distinctly different results concerning the efficiency and scale elasticity scores at various tolerance levels of chance constraints.However,both models yield the same results at a tolerance level of 0.5,implying that the deterministic model is a special case of the stochastic model in that it reveals the same efficiency and returns to scale characterizations of banks.Second,the stochastic model generates higher efficiency scores for inefficient banks than its deterministic counterpart.Third,public banks exhibit higher efficiency than private and foreign banks.Finally,public and old private banks mostly exhibit either decreasing or constant returns to scale,whereas foreign and new private banks experience either increasing or decreasing returns to scale.Although the application of our proposed stochastic model is illustrative,it can be potentially applied to all firms in the information and distribution-intensive industry with high fixed costs,which have ample potential for reaping scale and scope benefits.

高等教育规模、城镇化与区域经济增长机制研究——基于省级面板数据的证据

高等教育规模是经济持续增长的重要因素,城镇化是否在高等教育规模对区域经济增长的影响中发挥了重要中介效应,需要进一步研究。为此,可以基于2004一2020年国家统计局省级面板数据,分析高等教育规模与区域经济增长的关系,辨析城镇化在两者关系中的作用,进而探究高等教育规模、城镇化对区域经济增长的影响机理。研究结果表明:高等教育规模促进区域经济增长具有直接作用;城镇化对区域经济增长具有正向驱动作用;城镇化在高等教育规模促进区域经济增长过程中发挥了中介效应。这也证明了“高等教育规模一城镇化一区域经济增长”机制的存在。为有效利用该机制,建议适度扩大高等教育规模,加快培养高层次创新人才,因地制宜加快新型城镇化建设,推动城镇产业结构升级,建设现代化产业体系,促进区域经济快速健康发展。

新制度经济学视角下我国公立医院规模增长解释框架研究

新医改以来,我国各级各类公立医院规模迅速增长,衍生出财政负担持续加重、卫生费用过快增长、社会基本医疗保险资金分布严重失衡等一系列问题。囿于对我国公立医院规模内涵和增长根源性动力认知的含混,传统经济学有关对我国公立医院规模增长的解释缺乏说服力。鉴于此,从新的经济学角度揭示我国公立医院规模增长的本质性驱动框架已成为指导我国公立医院下一阶段高质量发展的重大理论问题。采用复杂系统建模法测度了新医改以来我国公立医院规模增长状况;归纳了当代公立医院日渐复杂的制度谱系;借鉴新制度经济学制度自身成本和制度变迁成本的观点,从制度成本分析入手,提出在价格规制的前提下,公立医院通过规模增长补偿制度性成本是最佳策略;最后,围绕新医改以来,公立医院经历的囚徒困境博弈、猎鹿博弈、守规博弈三重情境,探明了我国公立医院规模从单体规模增长到延伸性规模增长、再到协同性规模增长的演进路径。

农业社会化服务与小农户的组织化:不同服务模式的比较

本研究通过对比政府主导型、市场主导型和村集体经济组织主导型社会化服务模式,讨论了小农户如何被组织起来以及组织成本由谁承担的问题。在由政府主导的社会化服务模式中,小农户因受到政府补贴的吸引而达成了临时的合作,但这种组织化具有暂时性。在市场主导型社会化服务模式中,小农户或被整合到规模经营主体的种植模式中,或被服务组织重塑。在这两种服务模式中,小农户都是被动的参与者,其组织化程度并未提高。村集体经济组织可能通过重建与小农户的双向权责均衡关系,通过收取服务费用的方式来解决组织成本问题。这种双向的权责均衡关系使村集体经济组织与小农户之间建立起有机的利益联结,从而使该组织对小农户的组织和动员成为可能。

天山北坡经济带城乡聚落格局变化与影响因素分析

以天山北坡经济带城乡聚落为研究对象,采用景观格局指数、地理信息系统(GIS)空间分析、位序-规模法等分析1980-2020年间城乡聚落格局的变化,结合地理探测器从自然、区位及社会经济因素探究城乡聚落格局的影响因素。结果表明:1980-2020年间,城乡聚落数量、规模持续扩张且趋于集聚,前20 a扩张以耕地、草地为主,后20 a以未利用地为主;城乡聚落密度变化显著,高密度区主要集中在各绿洲呈现“多核集中分布”特征,中密度区沿高密度区周围扩张,低密度区沿绿洲边缘分布并在非绿洲区有扩张;首位聚落规模发展较好,趋于位序-规模曲线,中型聚落略微发育,小型聚落数量持续减少;交通等区位因素是天山北坡城乡聚落格局的首位影响因素,社会经济因素次之,自然地理因素影响较小,各影响因素差异显著。

冷能梯级利用的港口多能微网双层不确定性经济调度

为有效挖掘港口液化天然气(LNG)冷能利用的低碳灵活性潜力,充分发挥多时间尺度协同优化效应,提出一种考虑LNG冷能梯级利用的港口多能微网(MEMG)鲁棒-随机双层不确定性经济调度模型。首先,考虑LNG深冷-中冷-浅冷等各个温区的低碳灵活性潜力,建立低温碳捕集-冷能发电-直接冷却的冷能梯级利用模型,并以此为基础形成捕集-存储-利用协同的碳处理流程。其次,根据等概率逆变换生成考虑预测误差时序相关性的风电场景,并基于Wasserstein距离的0-1规划模型进行场景削减。再次,针对风电预测误差随时间尺度增加而增大的特性,构建多时间尺度优化的鲁棒-随机双层不确定性经济调度模型,上层通过分布鲁棒优化保证日前预调度决策鲁棒性,下层通过随机优化保证日内滚动调度决策经济性。最后,仿真结果表明,所提考虑冷能梯级利用的鲁棒-随机双层调度模型在解决日前长时间尺度预测精度低与日内短时间尺度易陷入局部最优矛盾的同时,可赋予港口MEMG更多经济性、低碳性及供电灵活性。

大科学装置的建设运行、效应影响及经验启示:综述与评估

大科学装置具备重大科学意义、国家意义和社会意义,学界对大科学装置的关注与日俱增。基于科学引文索引数据库(WOS)和中国知网数据库(CNKI),对从社会科学角度研究重大科技基础设施的国内外文献进行搜集、筛选和编码,并展开系统分析和内容分析,对国内外重大科技基础设施研究进行系统全面梳理,把握整体研究脉络的同时,挖掘其研究特点。已有研究达成若干共识:大科学装置通过适应环境变化实现长期生存,对大科学装置的评估需要采用多维度、多手段的框架体系,大科学装置具有显著的科学效应和经济社会影响,但资源开放共享仍有不足。进一步对研究特征、演进逻辑和理论联系进行探讨发现,政府、高校与企业等主体间关系,对我国重大科技基础设施效率水平评估以及如何选择重大科技基础设施建设模式与运营模式从而提升效率具有重要作用,是未来研究的重中之重。其中,政府角色及边界是大科学装置研究中最核心的问题,管理模式与治理结构、产出评价和资源共享乃至各种影响效应在很大程度上均由其决定。

数字经济发展对种植业碳排放效率的影响研究——基于中介和门槛效应的实证检验

农业源温室气体排放量(碳排放)仅次于工业,种植业作为农业的基础,其碳排放量在农业中占据较大比重,种植业碳减排对于“双碳”目标的实现具有重要意义。在“碳达峰、碳中和”的碳排放格局下,数字经济已成为推动种植业绿色低碳高质量发展的新引擎。本文在理论探讨基础上,结合2011—2021年中国31个省(自治区、直辖市,不包括中国香港地区、澳门地区和台湾地区)面板数据,综合利用固定效应回归模型、工具变量模型、中介效应模型、门槛效应模型,实证考察了数字经济发展与种植业碳排放效率之间的内在关系。研究发现,数字经济发展对种植业碳排放效率具有显著的正向影响,且存在农业生产功能与区域异质性;数字经济发展通过促进技术创新和规模经营来抑制种植业碳排放,且“技术创新效应”的贡献份额大于“规模经营效应”;数字经济发展对种植业碳排放效率的促进作用还受经济发展水平的影响,当经济发展水平低于阈值时,数字经济发展对种植业碳排放效率的影响并不显著,当经济发展水平超过阈值后,数字经济发展能够对种植业碳排放效率产生显著的提升效应。

数字金融、创新创业效应与区域经济增长——基于规模与质量视角的分析

文章利用2011—2021年中国284个城市的面板数据,基于经济规模和质量的视角探讨了数字金融对区域经济增长的影响,检验了创新效应、创业效应、创新创业效应在此影响过程中的作用机制,考察了数字金融对区域经济增长的门槛效应。研究发现:数字金融对区域经济增长的作用存在差异,对经济规模型增长的作用程度大于经济质量型增长,该结论在经过内生性检验和稳健性检验后依然成立,并且这种影响具有政策和区位的异质性;创新效应、创业效应和创新创业效应在数字金融促进区域经济增长的影响过程中起到部分中介作用;数字金融对经济规模型增长的影响呈边际效用递增的双门槛效应,对经济质量型增长的影响呈现“U”型特征的三门槛效应。

不同类型城市用地面积与人口规模的标度律研究——以长江经济带城市为例

中国快速城镇化进程的一个突出矛盾是土地城镇化普遍快于人口城镇化.然而,不同类型城市用地面积与人口规模的增长关系尚不清楚,且缺少从复杂城市系统视角认识人地关系演化规律.该文以长江经济带县级及以上城市为例,使用城市标度律探究不同类型城市用地面积与人口规模非线性关系,从用地结构视角揭示城市人地关系及演化规律.结果表明:1)2012—2021年,道路交通设施用地增速明显快于城市人口,是土地城镇化快于人口城镇化的主因.2)城市用地与人口规模总体上呈亚线性关系,体现了规模经济效应;但工业用地与人口规模呈超线性关系,反映了大城市工业用地供给过多的系统性偏差.3)基于规模调整指数的用地效率评价结果显示:在同等规模城市中,长江中游城市人均居住用地偏少,工业用地规模调整指数“东多西少”的空间特征更加明显.复杂城市系统理论为认识城市人地关系及演化提供了新方法,未来需要从用地结构和空间布局两个方面因城施策,优化调整城市人地关系.

受致灾气旋影响的不同规模等级城市直接经济损失特征

本文将造成直接经济损失的热带气旋定义为致灾气旋。依据城区常住人口,将我国城市划分为小城市、中等城市、大城市三种规模等级,基于1984—2019年热带气旋灾情和路径数据筛选出致灾气旋,分析我国城市的致灾气旋频次、强度,并研究致灾气旋造成的不同规模城市直接经济损失变化。主要结论为:(1)1984—2019年影响我国城市的致灾气旋为7.7个·a^(-1),呈微弱下降趋势,而强台风和超强台风的发生频次呈显著增加趋势(α=0.05显著水平),30°N以南城市频次整体比北部高;(2)由于致灾气旋影响范围增加,暴露于不同强度致灾气旋的城市个数呈增加趋势,其中暴露于强台风的城市个数增速最快,约为2.0个/(10 a);致灾气旋影响城市个数增加以及城市经济快速发展,使得暴露于致灾气旋影响范围内的经济总量迅速增加,以大城市经济暴露度(占比81.7%)的增速最快(402.6亿元·a^(-1));(3)1984—2019年致灾气旋造成的城市直接经济损失约为262.3亿元·a^(-1)(以2019年市值),呈增加趋势;城市经济快速发展和高强度致灾气旋频次增加的共同作用下,城市经济损失占我国致灾气旋经济损失的比重从30.0%增加到63.3%。大城市资产财富集中,且多位于沿海地区,致灾气旋发生频次较多,经济损失占比最大(为51.4%),增速最快(为5.2亿元·a^(-1))。