Reformulating Environmentally Constrained Traffic Equilibrium via a Smooth Gap Function

Various government laws have recently been enacted to alleviate the environmental deterioration of transportation systems. Environmental constraint is a valid means to explicitly reflect various environmental protection requirements imposed by the government. In this paper, we examine the environmentally constrained traffic equilibrium problem (EC-TEP), which is a fundamental tool for modeling and evaluating environmental protection requirements. Specifically, we provide an equivalent reformulation for the EC-TEP. The proposed reformulation adapts the concept of gap function to simultaneously reformulate the nonlinear complementarity conditions associated with the generalized user equilibrium conditions, environmental constraints, and conservation constraints as an equivalent unconstrained optimization problem. This gap function reformulation has two desirable features: (1) it can handle a general environmental constraint structure (linear or nonlinear; link-based or area-based) and a general link and route cost structure, enhancing the modeling adaptability and flexibility; (2) it is smooth and unconstrained, permitting a number of existing efficient algorithms for its solution. A gradient-based solution algorithm with a self-regulated averaging stepsize scheme is customized to solve the reformulated unconstrained optimization problem. Numerical examples are also provided to demonstrate the modeling flexibility of the proposed EC-TEP reformulation.     

媒体关注与企业创新绩效

媒体关注是会发挥信息功能的正面效应进而促进企业创新,还是会发挥负面效应给管理者形成外部压力从而抑制企业创新？在梳理媒体关注信息功能的基础上,基于2010~2018年A股上市公司数据分析媒体关注与企业创新绩效的关系。研究发现：媒体关注对企业创新绩效起到促进作用,在控制了内生性问题后,这一结论依然成立。通过对报道性质进行区分,发现非负面报道对创新绩效的促进作用更加明显,而负面报道并没有显著降低企业创新绩效。在影响机制分析中发现融资约束在媒体关注与企业创新绩效之间起到中介作用,即媒体关注通过缓解企业融资约束进而提高创新绩效。     

Credit constraints and productivity of SMEs: Evidence from Canada

To what extent firms are constrained by external credit is usually unobserved in commonly used firm-level data. We use a survey of financing among Canadian small and medium-sized enterprises to measure the likelihood of a firm being constrained by credit. We find that firm size, current debt-to-asset ratio and cash flow are robust indicators of being financially constrained, while long-term debt to asset ratio is not a significant indicator of credit constraints. We then estimate the firm-level total factor productivity, taking into account the measured credit constraints. Omitting credit constraints leads to an upward bias of productivity estimates, by 4 percent. In addition, we find no strong evidence that suggests credit constraints lead to slower productivity growth. Finally, we confirm that both investment and employment growth are negatively affected by the measured credit constraints.     

Existence of solutions to principal–agent problems with adverse selection under minimal assumptions

We prove an existence result for the principal–agent problem with adverse selection under general assumptions on preferences and allocation spaces. Instead of assuming that the allocation space is finite-dimensional or compact, we consider a more general coercivity condition which takes into account the principal’s cost and the agents’ preferences. Our existence proof is simple and flexible enough to adapt to partial participation models as well as to the case of type-dependent budget constraints.     

Effects of financial constraints on export performance of firms during the global financial crisis: microeconomic evidence from Korea

This study uses a manufacturing firm-level panel data set of South Korea for 2006–2013 to investigate the effect of financial constraints on the export performance of firms, with particular emphasis on the corporate ownership structure. The empirical results show that foreign multinational corporation (MNC) subsidiaries are not affected by financial constraint during both crisis and noncrisis periods, implying advantages of foreign ownership. However, domestic firms suffer more from financial constraints on exports during crisis years. In particular, domestic firms without parent firms are financially constrained during both crisis and noncrisis periods. However, those with parent firms do not experience financial constraints during noncrisis periods, although they too suffer from them during crisis periods. Thus, parent–subsidiary linkage among domestic firms plays an important role in alleviating financial constraints on export activity in noncrisis years but not as much during crisis years. Therefore, domestic parent firms exhibit less resilience to the global financial crisis, in comparison to foreign MNC parent firms.     

Financial constraints on export market exit of domestic firms versus foreign multinational corporation subsidiaries in South Korea

Using a Korean manufacturing firm-level data set covering a range of years from 2006 to 2013, this study investigates how the financial condition of firms, such as liquidity, leverage, and cash flow ratio, affects exit from export markets. It also analyses whether the financial status of foreign multinational corporation (MNC) subsidiaries differs from that of domestic firms with respect to the hazard of export market exit, especially during a global financial crisis. The empirical results confirm that, for domestic firms, the hazard of export market exit is affected by the firms’ financial condition only during a financial crisis. In other words, the financial vulnerability of domestic firms increases during the crisis, resulting in the hazard of export market exit. However, financial situations for foreign MNC subsidiaries do not affect exits from export markets, indicating a ‘finance-factor comparative advantage’.     

物流工程项目管理中“激励机制”构建的几点思考

物流工程项目管理中,对激励实现途径的探寻一般根据:需求层次理论、双因素理论等经典模型。这些基于人性Y理论假设的命题,固然是符合经验的,但是,这种激励途径的获得更多在于对个体主观偏好的把握,这样就使得方案的随机扰动性增强。为此,在机制设计理论与声誉约束机制这两个框架内,来思考物流工程项目管理中激励机制的构建,则形成该文的任务。     

论土地财政的逻辑——基于城市扩张对全要素生产率的溢出效应

从软预算约束的角度对地方政府的土地财政行为进行分析,使用我国1999～2009年的面板数据,运用数据包络分析方法对城市全要素生产率的增长进行了实证研究。结果表明,全国29个省市的TFP都呈现出上涨的趋势,几乎所有的全要素生产率的增长都归功于技术进步,每个省或多或少都存在产出效率低下问题,并用一阶差分GMM估计方法验证了建成区面积对我国经济增长有着显著的溢出效应。     

预算约束与金融制度选择的新理论:文献述评

本文的考察发现,在预算约束与金融制度结构之间存在着十分紧密的逻辑联系,而且国内外不少文献已经围绕于此展开了广泛而深入的讨论。针对预算约束与金融制度选择的关系,现有文献的理论发现大致包括三个层面:第一,虽然缓解乃至消除软预算约束是任何一种金融体系共同面临的挑战,但软预算约束的消除并非一定有利于长期经济增长;第二,分权的或者集权的金融体制都具有"内生性",因此,至少在理论上无法对其进行孰优孰劣的直观评判,同时也无法在它们之间进行简单的复制和移植;第三,金融体系应对预算约束问题的能力要远弱于企业制度,因此,当一个国家面对预算约束问题时,应当首先着手改善微观经济基础的金融需求结构,而不是调整金融供给结构。     

习惯形成、不确定性、流动性约束与居民消费——基于省际动态面板数据的实证分析

文章利用1998-2008年的城乡省际面板数据,建立包含习惯形成、不确定性和流动性约束在内的动态面板模型并对其进行实证分析.实证分析的结果表明习惯形成对于城乡居民的消费具有显著性影响;不确定性对于城镇居民的消费增长具有显著的影响,对于农村居民的影响不显著;城乡居民的消费具有过度敏感性;城镇居民的实证结果支持"前景理论",不支持流动性约束理论,农村居民的实证结果支持"短视行为"理论.