Optimal investment with vintage capital: Equilibrium distributions

The paper concerns the study of equilibrium points, or steady states, of economic systems arising in modeling optimal investment with vintage capital, namely, systems where all key variables (capitals, investments, prices) are indexed not only by time but also by age. Capital accumulation is hence described as a partial differential equation (briefly, PDE), and equilibrium points are in fact equilibrium distributions in the variable of ages. A general method is developed to compute and study equilibrium points of a wide range of infinite dimensional, infinite horizon, optimal control problems. We apply the method to optimal investment with vintage capital, for a variety of data, deriving existence and uniqueness of equilibrium distribution, as well as analytic formulas for optimal controls and trajectories in the long run. The examples suggest that the same method can be applied to other economic problems displaying heterogeneity. This shows how effective the theoretical machinery of optimal control in infinite dimension is in computing explicitly equilibrium distributions. To this extent, the results of this work constitute a first crucial step towards a thorough understanding of the behavior of optimal paths in the long run.     

资本回报率、人力资本投资与收入不平等——基于Galor-Zeira模型的扩展

资本回报率下降对人力资本投资、收入不平等程度有较大影响。本文将可变资本回报率加入Galor-Zeira模型,理论推导发现:收入不平等陷阱并非不可逾越的障碍。当技能劳动力工资高于受教育固定成本时,随着资本回报率下降,接受教育的遗赠临界水平将降低,更多家庭将发现投资人力资本是有利的,稳态的技能劳动力比例将提高。在当前资本回报率下降的大背景下,提高技能劳动力工资、降低受教育成本、对教育贷款实施财政减免优惠、为农村中等教育支出减负和提升农村教育质量、倡导节俭和重视遗赠的文化氛围在长期都有助于提高技能劳动力比重以及缓和收入不平等。     

自然资源依赖对城乡收入差距的影响研究

［目的］针对全国31个省（市、区）（不含港澳台地区）、自然资源依赖度高的地区和自然资源依赖度低的地区，从整体和分区域研究自然资源依赖对城乡收入差距的影响，探究不同区域其影响程度的差异性，进而为弱化各区域城乡收入差距，解决由城乡收入差距拉大造成的各类社会矛盾具有重要的现实意义。［方法］从理论上分析了自然资源依赖对城乡收入差距的影响，并利用1999—2017年的省级面板数据，运用固定效应模型，从全国和分区域实证分析了自然资源依赖对城乡收入差距的影响。［结果］针对全国，自然资源依赖会拉大城乡收入差距； 分区域结果，针对自然资源依赖度高的地区，自然资源依赖拉大城乡收入差距； 针对自然资源依赖度低的地区，自然资源依赖对城乡收入差距影响不显著。［结论］为缩小城乡收入差距，需要降低经济体对自然资源的依赖，针对自然资源依赖度高的地区，政府通过将部分自然资源收益转化为农业创新基金和农村基础设施投入，促进自然资源收益向农村公共资本转化，完善现有的自然资源收益分配及转化制度； 鼓励资源型产业技术创新，加大研发投入，延长资源产业链； 加大农村教育投入、提升农村人力资本质量。     

The role of innovation in venture capital: empirical evidence from European Union and EFTA countries

This article investigates the effects of innovation attempts on the venture capital and investment activity in the cases of the selected European Union plus European Free Trade Agreement countries using annual panel data and by controlling for real income growth and business sophistication. Our findings suggest that innovation has positively significant effects on venture capital in the cases without opt-out countries (United Kingdom and Denmark); however, these effects become negative in the cases with opt-out countries. Policy implications are provided in the conclusion section of this study.     

Airports’ managerial human capital,ownership, and efficiency

Airport performance differences require a better understanding of the sources of efficiency and competitive advantages. Globalization drives the air transport industry into a more market-orientated business questioning the relationship between managerial decisions and airport performance. Aviation management studies do not consider managerial capabilities and skills since they are intangible exogenous factors that are difficult to assess. In this study, a stochastic frontier analysis is performed accounting for top managers' theoretical knowledge and experience enclosed as exogenous drivers of airports' efficiency. The model analyses 12 Polish airports from 2009 to 2017. The results show a diversity of airports with a different number of passengers as efficient. The top managers' experience, when gained in the same airport, has a positive impact on airports' technical efficiency. Airports having unstable management are more technically inefficient. Independently of the efficiency level, some airports change their management after the national elections, suggesting that managers are chosen by political interest rather than by their specialised knowledge or their prior experience in aviation management. The results suggest that more practical knowledge improve airports’ performance. Airports with a majority of government ownership that are the largest ones increase their efficiency significantly, suggesting that political decisions may be discriminatory in detriment of airports managed by regional and city authorities.     

基于跨境社交平台的产品推广模式研究

论文调查分析了近年来热度较高的跨境社交媒体平台以及相关使用数据,利用相关性分析方法分析了多个平台的数据,在此过程中发现了各平台间具有相当高的互惠性,并运用互惠比例和推广方式适配度模型完成了对跨境社交平台的运行模式以及推广方式的对比分析,最终研究得出跨境社交媒体平台的产品推广模式。     

Moral hazard,debt overhang and capital structure

This paper investigates the impact of managerial moral hazard on the debt overhang of a firm by constructing a contingent claims model in which the manager faces costly effort. Using a calibrated capital structure model, we show that the costs of debt overhang become more serious in the presence of managerial moral hazard. Such costs even account for more than half of the total agency costs at a high level of cash flow. Moreover, in contrast to the results of Hackbarth and Mauer (2012), our model predicts a U-shaped relationship between the leverage ratio and investment opportunities of a firm, which is caused by managers’ moral hazard. Finally, by considering this moral hazard, we also show the coexistence of low leverage ratios and high credit spreads, which explains the phenomenon of “low debt levels and high credit spreads” observed in practice.     

Natural resources,technological progress,and economic modernization

The present inquiry focuses on the modernization perspectives of the commodity‐exporting countries through the lens of development economics. To this end, the study adopts the Kaldorian framework to address the modernization effects, epitomized in the absorption of surplus labor. To trace the process of economic modernization, the study augments Lewis’s dualistic economy model by the extractive sector. Three different scenarios for the management of resource revenues are scrutinized. An altruistic mode, which implies a pure redistribution of the revenues among the poor swaths of the population, protracts the process of economic modernization, requires a greater amount of capital stock, and harbors a greater risk of a poverty trap. This effect is less pronounced if the modern sector is more capital‐intensive. A productive mode, which elicits full reinvestment of the commodity revenues, in contrast, accelerates the pace of economic modernization. Further, predicated on the scrutiny of a more realistic scenario, a bargaining mode, the study derives the condition for a net positive (or negative) modernization effect. The study identifies technical progress alongside capital accumulation as a further important source of economic modernization.     

社会资本与超额在职消费：激浊扬清还是推波助澜

作为企业治理的重要问题之一，代理成本诱发超额在职消费引起各界广泛关注。文章以2007-2019年A股上市公司为初始样本，考察我国各省社会资本水平差异对超额在职消费影响。研究表明，社会资本显著提高超额在职消费，起到推波助澜的负面效用；进一步研究表明，公司治理水平维度上通过提高机构投资持股比例、短期债务融资比例及扩大独立董事比例和监事会规模均能抑制社会资本加剧超额在职消费的负面效用，公司治理环境维度上通过强化企业内部治理环境、加快市场化进程亦能削弱社会资本对超额在职消费的“推波助澜”。以上结论为社会资本利弊之争提供有益补充，亦凸显非正式制度与正式制度的治理替代效应，同时为企业完善内部治理水平及政府优化制度环境与规则治理以抑制社会资本负面效用提供一定借鉴。     

上市公司营运资金管理问题探析

本文从财务分析的角度出发并在运用管理学原理的基础上,综合评价和分析了上市公司在营运资金管理中存在的四个频率较高的问题。包括不合理的营运资金结构、营运资金运营效率低、营运资金不充足、滞后的管理模式。本文通过对国外发达国家关于营运资金管理的理论分析和实践经验介绍,在充分研究当前市场环境的条件下,对发现的上市公司营运资金管理问题,推导出相应的解决方案,以供企业参考。