Economic uncertainty,oil prices,hedging and U.S. stock returns of the airline industry

This paper examines the impacts of economic policy uncertainty and oil price shocks on stock returns of U.S. airlines using both industry and firm-level data. Our empirical approach considers a structural vector-autoregressive model with variables recognized to be important for airline returns including jet fuel price volatility. Empirical results confirm that oil price increase, economic uncertainty and jet fuel price volatility have significantly adverse effect on real stock returns of airlines both at industry and at firm level. In addition, we also find that hedging future fuel purchase has statistically positive impact on the smaller airlines. Our results suggest policy implications for practitioners, managers of airline industry and commodity investors.     

利用取土场废置高边坡进行景观提升改造的技术应用

对一县城道路入口处的废置取土场37m高边坡进行治理,并根据取土场现状地貌设计假山、人工瀑布、绿化设计等进行景观提升改造,通过优化绿地空间格局,完善公园的游览系统、服务设施、植物群落等方面,有效改善入城口区域城市风貌,同时也为周边的社区居民提供日常休闲、娱乐、游览和康体活动的公共空间,并充分发挥其作为南部新城区域中心森林氧吧的生态作用,形成稳定的、可持续发展的城市绿色生态系统。     

Effects of employees’ opportunities to influence in-store music on sales: Evidence from a field experiment

The effects of in-store music on consumer behavior have attracted much attention in the marketing literature, but surprisingly few studies have investigated in-store music in relation to employees. By conducting a field experiment in eight Filippa K fashion stores in Stockholm, Sweden, we investigate whether it is beneficial for store owners to give employees more opportunities to influence the in-store music. We randomly assigned the stores into a treatment group and a control group, with the employees in the treatment stores having the opportunity to influence the in-store music through an app developed by Soundtrack Your Brand (SYB). The experiment lasted 56 weeks and sales data were also gathered 22 weeks before the experiment, resulting in a total of 4626 observations. Our results show that sales decreased by 6% when the employees had the opportunity to influence the music played in the store, and the effect is driven by a reduction in sales of women's clothing. Interviews with the employees revealed that they had diverse music preferences, frequently changed songs, and preferred to play high-intensity songs. Employees thus seem to make choices regarding the in-store music that reduce sales, implying that store owners might want to limit their opportunities to influence the background music.     

效率视角下"一带一路"沿线国家创新影响力研究

从效率差异视角构建国家创新影响力评价方法，揭示“一带一路”沿线国家创新要素流动倾向性以促进交流合作。运用DEA模型测算各国创新效率，根据DEA原理识别国家间的认可关系，构建创新网络并用节点特征向量中心度表示各国创新影响力，分析创新影响力类型、创新网络特征及创新投入冗余率与产出不足率。结果发现，各国创新效率存在显著差距;各国分别处于创新网络中心、核心和边缘位置，国家创新影响力依次递减;按照创新要素相对强度，沿线国家可分为6种创新类型;最后，提出沿线国家间开展创新交流与合作的必要性和途径。     

Feelings of ownership and volunteering: Examining psychological ownership as a volunteering motivation for nonprofit service organisations

Given many nonprofit service organisations rely on volunteers to provide valued services to their communities, examining the factors that impact the retention and recruitment of volunteers is of central importance for the success and longevity of many community-based services. Psychological ownership is a phenomenon whereby objects that are not physically or legally possessed can be the target of ownership feelings. While such psychological ownership has been examined in the paid-employment literature as an antecedent for prosocial behaviours, there has been no examination of psychological ownership within the volunteering literature. As such, this paper examines the role of psychological ownership as a factor in volunteer retention for predominantly community-based nonprofit service organisations by examining how the sense of ownership over the nonprofit service provider affects volunteering attitudes and intentions. Alongside ownership, previous volunteering behaviours, and time pressures are also examined as contributing factors. Results indicate that volunteering does increase ownership perceptions, and those ownership perceptions have positive outcomes for volunteering behaviours. However, time pressure is a significant moderator of these relationships and different volunteering behaviours can be observed for high and low time-pressured volunteers.     

微纳卫星组网星间链路设计及关键技术分析

微纳卫星组网应用可大幅度提高航天装备的能力，较单颗大卫星具有明显的优势。首先，介绍了国内外微纳卫星组网的研究情况，以组网侦察应用为例分析了星间测量与通信链路的技术需求，并进行了系统架构和体制设计；其次，在星座设计基础上开展系统仿真，并提出了一体化设备实现方案；最后，分析了微纳卫星组网系统中几项重要的关键技术及其解决方案，对系统的设计和工程实现具有参考价值。     

结构性去杠杆下的中国宏观经济*——2018年中期中国宏观经济分析与预测

2018年以来中国经济平稳运行，物价水平稳定，就业形势整体向好，经济增长质量稳步提升。不过，当前中国经济仍然面临一定的下行压力，尤其需要警惕消费增速过快下滑、宏观税负进一步加重、民间投资复苏乏力、部分企业效益状况显著恶化、去杠杆过程中金融体系不稳定性加剧等主要风险点。此外，杠杆率高企是现阶段中国经济面临的突出问题，而且中国的杠杆率在不同部门之间以及各部门内部均体现出明显的结构性特点。为此，中央在2018年专门提出了“结构性去杠杆”的新思路。在“结构性去杠杆”稳步推进的大背景下，宏观政策既要积极应对经济下行压力，谨防去杠杆带来的经济增速超预期下滑风险，又要激发经济内生增长动力，促使经济实现长期可持续发展和“高质量发展”。     

复杂地质条件下高面板堆石坝工程质量控制措施阐述

在复杂地质条件下,需要加强高面板堆石坝工程质量管控工作,严格地按照国家出台的质量安全责任规章,提高建设质量。论文主要围绕高面板堆石坝工程、工程质量控制措施两个方面进行探讨,确保混凝土面板堆石坝的施工质量。     

机构投资者能抑制盈余管理吗?--基于退出威胁视角的经验证据

退出威胁是股东参与公司治理的重要方式。本文以2010?2017年A股上市公司为样本,检验机构投资者的退出威胁与企业盈余管理之间的关系。结果显示:机构投资者能够抑制企业的真实盈余管理,而对应计盈余管理的影响并不显著;机构投资者退出威胁能够降低真实和应计盈余管理水平。进一步考虑机构投资者异质性发现,相比敏感型机构投资者,抗压型机构投资者退出威胁更可能降低企业真实盈余管理水平;当管理层的薪酬对股价越敏感时,机构投资者退出威胁的作用越大;机构投资者退出威胁的影响效应在民营企业中更显著。本文的研究结论为认识我国机构投资者,尤其是以QFII和社保基金为代表的抗压型机构投资者在公司治理中的作用提供了新的思路。     

Relationship between city size and firm productivity – A new interpretation using the Chinese experience

This paper contributes to the literature on the relationship between city size and firm productivity by focusing on agglomeration, selection (market competition), and sorting (presence of firms with diverse productivity) effects using Chinese firm-level data for 1998–2013. Contrary to the existing literature, our parametric regression estimates from nearly two million firms show that when the selection effect is controlled, productivity advantage in big cities is reversed. This outcome is explained through a quantile regression showing the existence of left-sided sorting (inefficient firms sort themselves to larger cities) in big cities which is not captured in existing empirical literature. We further find that (1) left-sided sorting is stronger in exporters than non-exporters; (2) is also generated mainly in enterprises with high asset-liability ratios; and (3) selection has a positive effect on firm productivity, suggesting that market competition is key in an explanation of the rapid growth of big cities in China.