公司内部人具有交易时机的选择能力吗?——来自中国上市公司内部人卖出股票的证据

本文以内部人卖出股票的交易为对象,研究发现从短窗口来看,上市公司内部人卖出本公司股票时表现出很强的时机把握能力。回归分析发现,在卖出股票时,除董事长和总经理外的内部董事和经理的超常回报显著高于监事和独立董事,董事长和总经理的超常回报可能低于监事和独立董事;内部人本人交易的超常回报显著高于内部人直系亲属;小规模公司内部人的超常回报显著高于大规模公司内部人;国有控股公司内部人的超常回报可能高于其他公司内部人。本文经验证据表明,内部人的时机选择能力可能来自于其掌握的非公开信息,且受公司信息透明度影响。     

铝合金外窗质量控制要点及改进措施

近年来,铝合金窗越来越普遍用于住宅小区、办公大楼、公共场所等地。由于铝合金窗产品的质量问题直接涉及消费者的人身健康及财产安全,经常遇到质量投诉;根据多年的检测经验,对铝合金窗从设计到生产及安装过程中的控制要点及改进措施进行探讨。     

某车型后门框胶条和后侧窗玻璃质量改进

文章分析了上汽通用五菱汽车股份有限公司某款车的后门框胶条和后侧窗玻璃在开发过程中遇到的问题,并对其质量改进进行了总结。     

深圳经济特区:中国对外经济政策的窗口——以深圳作为中国对外经济政策窗口作用论述为中心

邓小平关于经济特区是中国"对外政策的窗口"的著名论断,其完整的内涵表现在:经济特区是中国反对霸权主义和强权政治的窗口;经济特区是中国维护世界和平的窗口;经济特区是加强中国同第三世界的团结和合作的窗口.不能简单地把经济特区定义和解释为"对外开放的窗口",在和平与发展为主题的国际大背景下,改革开放以来的深圳经济特区,一直发挥着中国对外政策尤其是对外经济政策窗口的作用.     

Optimal rebalance rules for the constant proportion portfolio insurance strategy – Evidence from China

The constant proportion portfolio insurance (CPPI) strategy is one of the most popular asset allocation strategies employed by guaranteed-return financial products investors. Rebalance disciplines play an important role in determining the CPPI performance in practice. This paper examines whether the selection of rebalance rules affects CPPI strategy performance in the context of Chinese equity markets and, if so, in what pattern, and whether an optimal parameter of rebalance exists. We find that, (1) the three alternative rebalance disciplines – time discipline, market move discipline and lag discipline – are indifferent in affecting the performance of CPPI strategy; (2) in terms of optimal parameters of each rebalance rule, the optimal rebalancing period for the time discipline is 3 trading days, the optimal trading threshold of the market move discipline 4%, and the optimal lag factor of the lag discipline 6%. These optimal parameters are not influenced by the length of investment.     

基于改进GA的滑行道路径冲突解脱研究

为解决多航空器在飞行区场面活动时存在的冲突问题,以优化后的滑行路径距离作为目标代价函数,提出一种滑动时间窗与GA相融合的冲突解脱模型。首先在滑行规则、安全间隔与滑行道实际条件等约束条件下构建场面滑行路径模型;其次提出基于滑动时间窗与GA融合的求解算法;最后选取成都双流机场为例进行仿真,并与传统GA算法进行对比分析,证明基于改进GA的算法模型在飞行区冲突解脱上更具有鲁棒性与自适应性。     

Does economic policy uncertainty affect cryptocurrency markets? Evidence from Twitter-based uncertainty measures

Using daily data from August 9, 2015, to July 7, 2020, this study examines the effects of economic policy uncertainty (EPU) on the returns of four cryptocurrencies: Bitcoin, Ethereum, Litecoin, and Ripple. To this end, two new measures of EPU (Twitter-based economic uncertainty and Twitter-based market uncertainty) are considered. A Granger causality test using the recursive evolving window approach shows a significant causality between the Twitter-based EPU measures and the BTC/USD exchange rate from October 2016 to July 2017. Moreover, a significant causality was noted from the EPU measures to the ETH/USD exchange rate from June 2019 to February 2020 and from the EPU measures to the XRP/USD exchange rate from January 2020 to February 2020. The Twitter-based EPU measures primarily positively affect the returns of the related cryptocurrencies during these periods. These results are robust to different measures of Twitter-based EPU and different econometric techniques. Potential implications, including the COVID-19 era, are also discussed.     

武汉老橱窗特征解析

武汉老橱窗是当时社会生活的缩影：老橱窗是经济大潮起落的风向标,是政治风云变幻的晴雨表,是都市生活的流行时尚眼,是商店卖场的无声宣传员,是艺术空间的多彩百花园。     

The trade-off between fixed vehicle costs and time-dependent arrival penalties in a routing problem

This paper introduces the vehicle routing problem with soft time windows (VRPSTW) in which problem definition differs from ones previously defined in literature. Branch-and-price approach is employed, resulting in a set partitioning master problem and its new subproblem. Novel techniques are consequently developed to solve this new subproblem. Experimental results report the comparisons of these solution techniques under the branch-and-price framework. The VRPSTW solutions have further been compared to the state-of-the-art literature, signifying the superiority of the VRPSTW on this issue.     

Bush v. Gore and the Effect of New Source Review on Power Plant Emissions

New Source Review (NSR) is a Clean Air Act regulation that requires electric utilities to meet emission standards when making modifications to existing power plants. The regulation increases the cost of replacing worn out parts, and limits the firm’s scope of potential capital investments. Such restrictions may lead to greater retirements and lower utilization, adversely affecting profits. Prior to the 2000 presidential election, investors expected Bush to have a narrower interpretation of NSR than Gore. Therefore, we use changes in stock prices to estimate the effect on profits of differences in NSR policy. Our results indicate that investors expected the average boiler to be $38 million more valuable under the Bush administration. Over the boilers’ lifetimes, the additional utilization will have increased emissions by 19 million tons of sulfur dioxide, 5.9 million tons of nitrogen oxides and 980 million tons of carbon dioxide, relative to natural gas generation.