Do analysts add value when they most can? Evidence from corporate spin‐offs

This article investigates how securities analysts help investors understand the value of diversification. By studying the research that analysts produce about companies that have announced corporate spin‐offs, we gain unique insights into how analysts portray diversified firms to the investment community. We find that while analysts' research about these companies is associated with improved forecast accuracy, the value of their research about the spun‐off subsidiaries is more limited. For both diversified firms and their spun‐off subsidiaries, analysts' research is more valuable when information asymmetry between the management of these entities and investors is higher. These findings contribute to the corporate strategy literature by shedding light on the roots of the diversification discount and by showing how analysts' research enables investors to overcome asymmetric information. Copyright © 2013 John Wiley & Sons, Ltd.     

Expanding airport capacity of cities under uncertainty: Strategies to mitigate congestion

Airport capacity constraints are increasingly challenging the growth of air traffic. At the same time, decision-making about airport capacity investments is extremely complex, involving trade-offs. This paper’s objective is to optimise a privately owned airport system’s capacity investment decision in a city under demand uncertainty. Next to the investment size, our real options model incorporates the timing of the investment, as well as the cost of congestion. The results reveal that the larger a city’s initial airport capacity, the smaller its investment will relatively be and the lower the occupancy rate threshold at which investment will take place. We also show that, in case of a higher demand growth combined with more demand uncertainty, the city will benefit from a significantly larger investment, but made later at a higher occupancy rate. In this case, cities with a small initial capacity will sometimes even more than double current capacity. Higher airport charges and an increase in non-aeronautical revenues both lead to a later investment in more capacity, due to the increased project attractiveness. An increase in congestion costs results in a larger investment made earlier, in order to eliminate delays. Airport operational cost and capacity holding cost increases both lead to smaller investments.     

Study of emerging air taxi network operation using discrete-event systems simulation approach

This research focuses on understanding the air taxi operations to determine the number of air taxis required to fulfill the demand for urban air mobility in New York City (NYC). We leverage the Define, Measure, Analyze, Design, and Verify (DMADV) framework and integrate it with the systems simulation approach. Upon investigation, we find that all the parameters linearly impact the vehicle utilization, while other measures are robust, specifically with respect to the seating capacity. It is also recommended to operate initially with 70 air taxis in NYC to achieve a trade-off between customer wait time and vehicle utilization. The proposed approach can act as a recommender system for air taxi companies.     

环境信息披露对上市公司企业价值的影响——“组织可见度”是否起到中介作用

我国现行企业环境信息披露政策下,企业对于信息披露的方式、时间等有很大的自由裁量权力。因此,企业这一社会责任的自觉履行需要企业价值最大化等动机支撑,但其作用机理是否有效,投资者的关注度及解读尤为重要,亦即“组织可见度”在环境信息披露对企业价值的影响中扮演重要角色。本文以我国化工行业上市公司2013-2017年样本,实证检验环境信息披露对企业价值的影响,并依次从分析师关注水平和媒体关注水平两个角度衡量组织可见度,检验其是否具有中介效应,并分析所有权性质差异下的不同结果。结果表明:环境信息披露能提升企业价值,组织可见度在环境信息披露对企业价值的影响过程中发挥了部分中介效应。进一步研究发现,当使用分析师关注水平衡量组织可见度时,该中介作用只体现在国有企业中;当使用媒体关注度衡量组织可见度时候,该中介作用在两种类型的企业中均只得到了部分体现。企业环境信息披露政策本意是通过其影响企业的市值表现促进企业更好地履行其环境社会责任,本文通过揭示其中组织可见度的中介作用,有助于启示企业对其市值管理、有关管理部门对企业履行环境社会责任引导时的操作思路。     

悬臂式掘进机回转机构的分析与建模

基于悬臂式掘进机回转机构的结构特点,对其液压控制系统的运行原理展开分析,并结合假设条件建立液压元件的基本方程,通过机理建模最后得到了系统的传递函数,为实现掘进机自动控制提供了实用的简化模型。     

接触网回流系统研究

本文主要分析了高速铁路在不同的供电方式下,容易出现的问题及产生的影响,在此基础上提出了解决的措施和建议,希望通过相关的改进措施达到更好地保护铁路沿线人员和设备安全的目的。     

矿井供电系统防越级跳闸应用与试验

矿井供电系统防越级跳闸技术研究成果于2014年10月在付煤公司35/6KV变电所、井下中央变电所、南翼集中变电所、北翼集中变电所、北翼一变、东四一变、东四三变以及各变电所外围需要装表计量的配电点得到全面应用。     

企业财务风险预警指标体系构建研究

本文以现有财务管理、财务预警系统理论和实践研究为基础,从筹资风险、投资风险、经营风险和收益分配风险四个方面建立财务风险预警指标体系,最后通过使用层次分析法、综合功效系数法等技术,设计了一套初级的企业财务风险预警模型。本文以我国深市所有石油上市公司为研究样本,有一定的实际价值。     

集团企业工作协同管理模型研究

集团企业逐渐成为我国经济发展的骨干和支柱[1]。如何解决好集团企业内部之间的协同管理问题已经成为集团生存发展的瓶颈问题[2]。本文对集团企业协同管理系统进行了深入地分析研究,对企业的发展具有一定的理论指导意义。     

美国学前教师职前培训体系演进之路省思与启示

美国是世界上学前教育最发达的国家之一,非常重视学前教育师资的培训和质量的提高,高素质的幼教师资主要通过职前培训这个途径来实现。本研究对美国学前教师职前培训体系发展历程进行了梳理,分为学徒制时期、培训学校时期、师范学校时期、师范学院时期和综合大学的教育学院和文理学院的教育系时期。反思不同时期美国学前教师职前培训的经验与教训,结合我国国情,在培训目标、课程设置、质量保障机制、教育实践等几个方面对我国学前师资的职前培训体系进行展望。