Investment opportunities and cash holdings of firms: an empirical study on Korean firms

We find that the cash flow sensitivity of cash holdings of firms whose investment opportunities are lower is significantly higher by examining a panel data of 898 Korean firms for 1999–2014. The cash flow sensitivity of investment is also found to be lower in case of low investment opportunity. Both findings suggest that firms decide to hold cash in response to an increase in cash flow when they do not have a good investment opportunity. Precautionary motive because of financial constraints and uncertainty, and agency problems, however, are not associated with the cash flow sensitivity of cash holdings. These findings imply that it is necessary to develop new investment opportunities to encourage firms to spend more cash in Korea.     

基于哈肯模型的高技术产业化过程机制研究

运用自组织理论和方法,在哈肯模型的基础上建立了高技术产业化过程的演化方程,并以北京、天津、上海、河北等29个省市为样本进行了定量化的实证研究。结果表明,研究开发投入强度是高技术产业化过程中的序参量,从而得出要依靠研究开发投入与高科技成果转化的协同作用促进高技术产业快速发展这一结论。     

Health Damage of Air Pollution: An Estimate of a Dose–Response Relationship for the Netherlands

This paper estimates the dose-response relationship between air pollution and the number of work loss days for the Netherlands. The study is based on illness data (work loss days) for the Dutch labour population and average year concentrations of air pollution in 29 districts. The dose-response relationship has been estimated by means of two different techniques: the ordinary least squares method (OLS) and the one-way fixed-effects method (OWFEM), which we consider to be more adequate. In general health effects are much smaller when OWFEM is applied than if OLS is used. With OWFEM a significant relationship is found between sulphate aerosol (SO₄), ammonia (NH₃) and the number of work loss days (WLDs). Particulates (TSP), O₃ and SO₂ have no significant effect on the number of WLDs. These results differ from those obtained in studies in the United States, which indicate that particulates (TSP) and other small particles, ozone (O₃) and to a lesser extent SO₄ and SO₂ significantly influence the number of WLDs.     

江苏省湿地的基本特征及保护

本文论述了江苏省湿地的基本特征,从可持续发展的角度,深入剖析目前湿地现状及存在问题,并提出了江苏省湿地生态系统保护利用的科学对策。     

基于时空路径的城市绿地享用公平性 研究——以成都市新、旧城区为例

从时空间行为视角切入，采用居民活动日志搜集成都市新、旧城区的绿地使用者时空路径数据集，辨识不同时间预算人群的潜在可用绿地分布及人群特征，并通过构建绿地时空享用量模型，从时空制约角度对成都市新、旧城区的绿地享用公平性展开分析。研究结果显示：1)成都市新、旧城区的绿地享用格局在辐射范围、享用强度和人群绿地享用时间预算方面具有时空间分异特征；2)日常出行链中固定性活动占比会对人群绿地享用时间预算产生影响；3)随个体时间预算不断被固定性活动所挤占，长距离通勤加班族、担负接送小孩上学的上班族等时间短缺型群体的绿地享用机会被深度制约，日益成为潜在的绿地享用弱势群体，在时间短缺型群体的潜在活动路径范围内增加绿地供给，有利于提高此类人群享用绿地的机会，从而提高片区的整体绿地享用公平性。     

以创新群为基础的自主创新战略研究

创新在时间和经济空间上具有群集特性。它发起于根本性的(自主)创新,并能够产生强烈的创新溢出效应。分析认为,将自主创新战略建立在创新群的基础上,培育以国家战略性技术为核心的自主创新群,能够将创新能力的内生性与外生性较好地结合在一起,有利于我们实现完全的自主创新。     

民间资本供求与民营企业融资:对陕西的实证分析

本文建立在调研和有关资料基础上对陕西现实及潜在的民间资本供求进行测算分析,从总量和结构等方面实证了民间资本供给充足、而民营经济对民间资本的需求欲望非常强烈这一结论,要解除民间资本供求的市场失灵现象,就必须构建以"民资、民用、民管"为原则的内生性融资机制,建立社区民间金融管理组织和社区民间金融市场,选择内生性融资方式,创新其融资产品,实现民间资本供给与民营经济对其需求的有效对接.     

云南旅游品牌发展与对策分析

随着国际国内旅游市场竞争的日益激烈,我们应该意识到,旅游市场之争实质上是品牌之争。云南旅游业应该在充分认识自身旅游品牌发展存在的问题基础上,找出问题,寻求改进的措施,从简单的资源要素竞争转化为品牌经营竞争战略,不断地进行品牌建设和品牌创新,实现从旅游品牌到旅游名牌的飞跃。     

长江中游根治洪灾策略与措施的探讨

长江中游是长江自然—经济—社会复合生态系统的重要组成部分,当前洪涝灾害频繁而严重。按照长江洪水发生的自然规律调整好人与自然的关系,改变长期以来舍南保北、以堵为主、重蓄轻泄的做法,实施疏泄为主的防洪策略,并采取相应的工程和非工程措施(如下荆江裁弯、开辟分流洪道、四口建闸、洞庭湖水系南北分流、疏浚河道、南水北调及平垸行洪等),同时配合进行水源生态工程及江河库湖调蓄工程建设,才能根治长江中游洪涝灾害。     

广西乡村──城市转型与协调发展研究

本文揭示了“八五”期间广西乡村──城市转型发展的特征及其地理动力机制．预测未来15—25年内乡村──城乡转型发展的趋势、提出了促进乡村──城市转型与协调发展的一些对策建议。