扩大居民消费需求的制约因素及政策取向

随着市场格局的转变,消费需求逐步成为我国经济增长的主要制约因素。扩大国内需求是我国经济增长的长期政策取向。国内需求是由投资需求和消费需求构成的,消费需求是拉动经济增长的持久动力。从我国消费需求的构成看,居民消费需求的比重占有主导地位。因此,扩大消费需求主要是扩大居民消费需求。居民消费需求一旦启动起来,我国经济就能持续、快速增长。本文从理论和实践两个层面上,深入地研究了影响居民消费需求的制约因素,并提出了扩大居民消费需求的政策取向。     

社会保险成本过高是否抑制企业投资?

社会保险成本过高是否抑制企业投资，从而阻碍实体经济发展?对此，文章利用工业企业微观数据实证检验了企业社保成本变动对投资率的影响.为缓解内生性问题，文章选择城市老年人比重作为工具变量.实证检验显示企业社保支出比重增加1个单位标准差，企业投资率约下降3.3%，能够解释企业投资率变动的6.4%，具有较强经济显著性.文章还探究了社保成本变动影响企业投资的内在机制，发现劳动成本渠道、生产率渠道以及融资约束渠道都得到相关经验证据的支持.研究结果说明降低企业社保成本的政策如果能够得到有效落实，将会刺激企业扩大投资，促进地区经济发展.     

政府行为、金融环境与区域创业差距——基于中国省际面板数据的实证分析

中国作为一个正处于转型过程中的发展中国家，创业活动类型和创业环境都与成熟市场经济国家存在很大差异，经济体系中呈现"强政府、弱市场"的资源配置格局，金融市场化尚不完善。研究中国的区域创业差距问题必须基于中国目前转型经济条件下的特殊背景。文章旨在解决以下两个问题：政府行为和金融约束对中国区域创业差距产生了怎样的影响?中国转型背景下政府行为和金融市场的特殊性是否会对中国区域创业产生不同于成熟市场经济的影响?文章在研究框架上对流行的创业折衷框架进行修正，创新性地引入政府的行政规范程度、非税负担变量和宏观流动性约束变量，建立省际面板数据模型，实证分析了政府行为和金融约束对中国区域创业差距的影响。研究结果表明：政府管制程度的提高，无论对生存型创业还是机会型创业都将产生抑制作用；信贷环境方面，在目前金融市场化尚不完善的背景下，银行信贷资金在中国整个企业融资体系中仍然占据主导地位，信贷约束的放松和信贷可获得性的增强对中国的机会型创业行为产生显著的促进作用。     

On the structuralist constraints in social scientific theorizing

Several case studies and theoretical reports indicate that the structuralist concept of a constraint has a central role in the reconstruction of physical theories. It is surprising that there is only little theoretical discussion on the relevance of constraints for the reconstruction of social scientific theories in the literature. Almost all structuralist reconstructions of social theorizing are vacuously constrained. Consequently, constraints are methodologically irrelevant.In this paper I reconstruct three cases selected from social scientific theorizing. The first case is a generalization of Gross, Mason and McEachern's (1958) role expectation conflict theory, which is a qualitative theory. The second case is Cohen and Lee's (1975) quantitative theory of social conformity, which essentially utilizes the theor of Markov chains. The third case is the explanation schema of folk psychology which is one of the most important methodological frameworks in the social sciences.In all the three cases important constraints emerge. From an epistemological point of view it seems that the related constraints work as higher-order laws. In any case, purely conceptual arguments are insufficient to justify them.The three cases,mutatis mutandis, cover nearly all types of social scientific theorizing, so that in my view constraints play a crucial methodological role in the social sciences precisely as they have in the natural sciences.     

非线性极大极小问题的可行信赖域算法

针对一类非线性约束极大极小问题,利用极大熵方法将转化为带不等式约束的非线性规划问题,给出了一种可行信赖域算法,解决了不等式约束的非线性大系统优化问题,并证明了该算法的全局收敛性。初步的数值试验表明,对于该类极大极小问题,本算法有良好的数值表现。     

机构投资者持股会提高劳动投资效率吗？——基于中国A股上市公司的经验证据

培育机构投资者是建设高质量资本市场的重点,对推动供给侧结构性改革和优化企业资源配置起着关键作用。基于2010—2018年中国A股上市公司样本,从公司治理的角度出发,考察了机构投资者持股对劳动投资效率的影响。研究结果表明,机构投资者持股能够显著提高企业劳动投资效率,具体表现为机构投资者持股抑制了雇佣冗余,缓解了雇佣不足和解雇过度。中介效应检验结果显示,两类代理成本的降低和融资约束的缓解是机构投资者提高企业劳动投资效率的重要机制。进一步研究发现,在市场化程度高的地区,机构投资者持股对劳动投资效率的影响更显著,劳动密集度则对两者关系无显著影响。因而,吸引优质机构投资者、健全上市公司信息披露制度和加强市场化建设是提高企业劳动力资源配置效率的关键。     

An adjustable robust optimization model for the resource-constrained project scheduling problem with uncertain activity durations

This paper addresses the resource-constrained project scheduling problem with uncertain activity durations. An adaptive robust optimization model is proposed to derive the resource allocation decisions that minimize the worst-case makespan, under general polyhedral uncertainty sets. The properties of the model are analyzed, assuming that the activity durations are subject to interval uncertainty where the level of robustness is controlled by a protection factor related to the risk aversion of the decision maker. A general decomposition approach is proposed to solve the robust counterpart of the resource-constrained project scheduling problem, further tailored to address the uncertainty set with the protection factor. An extensive computational study is presented on benchmark instances adapted from the PSPLIB.     

Design-balanced capacitated multicommodity network design with heterogeneous assets

Management of assets plays an essential role in determination of service plans operated by carriers in the transportation and logistics system. In this paper, we introduce certain issues related to management of heterogeneous assets in the well-known design-balanced capacitated multicommodity network design, where design-balanced requirements are explicitly defined based on heterogeneous assets.Taking vehicles as an example of heterogeneous assets, we first present an arc-based formulation for the proposed problem and discuss two associated subproblems. We then propose a tabu search based metaheuristic for this problem. Over a wide range of network design instances, we respectively compare our approach with CPLEX with one-hour and ten-hour time limits. Computational results demonstrate that the proposed approach performs very well in terms of solution quality and computing time, especially for large instances.     

Structural constraints and excess capacity: an international comparison of manufacturing firms

Excess capacity results in real and opportunity costs as well as lower factor productivity. Conventionally, variation in capacity utilisation rates has been explained with reference to the business cycles and market imperfections. In this article, we show that these two factors do not always fully explain the causes of idle capacity. Our findings suggest that manufacturing firms in low‐income countries tend to have lower capacity utilisation (CU) rates than those in middle‐ and upper‐middle‐income groups. To explain this peculiarity, it is proposed in this article that the level of excess capacity partly depends on supply‐side conditions and institutional variables. The findings provide strong support for this view and suggest that there are gains to be made in the manufacturing industries of the lower‐income countries through improvements in the structural conditions.     

伊迪丝·华顿在《纯真年代》中对人性的理解

伊迪丝·华顿是美国文学史上最具影响力的女性作家之一,她的作品体裁广泛,尤以小说见长.其中《纯真年代》是最具代表性的一部.通过分析华顿对几位主人公的细致刻画和描写来探寻她在这部小说中对人性的理解,认为其理解具有明显的矛盾性和局限性.这些在三位主人公身上有着很好的体现.纽兰·阿切尔是一个勇敢的懦夫和理想主义者；梅·伟兰是一个复杂的社会产物,貌似单纯无知的外表下深藏心机；艾伦·奥兰斯卡是一个对社会传统的温和的反派人物,神秘、勇敢、崇尚自由却最终只能向传统低头.这与当时的社会背景以及她本人的人生经历是密不可分的.