投资风格、意见分歧与股票流动性——来自股票网络社区数据挖掘的证据

文章挖掘网络平台上投资者发帖的文本数据并使用Python语言编写情感分析程序，在区分价值型投资和技术型投资风格的基础上，建立了投资者的群体内意见分歧、跨群体意见分歧指标，并分析意见分歧程度对股票流动性的影响效应。实证表明：不同投资风格的投资者群体内意见分歧的程度有显著差异，价值型投资者群内意见分歧程度要高于技术型投资者；投资者的群体内意见分歧和跨群体意见分歧都与个股流动性水平呈现显著的负相关关系，也即投资者对个股看法的对立程度越高则个股的流动性水平越低，而且两者对流动性的影响具有较强的独立性；进一步的，意见分歧对流动性的影响效应会受到卖空限制的影响，随着卖空限制的减轻，这种影响效应显著增强。这些结论表明，单纯增加信息量并提高信息传播效率，并不一定能完全改善股票流动性水平，投资者的意见分歧既是现实情境，又可能会导致股票流动性的异动，进而影响股票市场的稳定。     

Analyzing passengers’ emotions following flight delays- a 2011–2019 case study on SKYTRAX comments

The text mining technology enables researchers or enterprises to automatically and efficiently access the information in text comments. This paper obtains 24,165 reviews from SKYTRAX between September 2011 and March 2019, 5700 of which express that passengers had experienced flight delays. It uses sentiment analysis based on a sentiment dictionary to classify user reviews and uses co-occurrence analysis to identify passengers' concerns on different aspects of service in the aviation industry. The results of the user sentiment analysis show that there is a significant and negative correlation between the user's emotions and their flight delay experiences. After flight delay, passengers' attention to the service aspects has increased, while satisfaction with the airport service has dropped dramatically. This paper shed some new light on public opinion about flight delays.     

Independently Certified Industry-specific Disclosures to the Capital Market: The JORC Code in the Australian Mining Industry

We investigate compliance with the Australian JORC Code for reporting mineral resources and ore reserves, the quality of the disclosure, and its impact on the capital market. The compliance and quality assessment is conducted by two experienced geologists who find that while the overall reporting quality improved after the 2012 revisions to the Code, they disagree on the extent of improvement. This reflects the uncertainties involved and the difficulty in interpreting the reports. Both geologists agree that the greatest improvement is seen in early-stage projects, consistent with the expectation that there are more uncertainties surrounding these, and the additional information disclosed under the 2012 JORC Code appears to assist in reducing the uncertainties to some extent. The capital markets study shows that JORC announcements have a significant impact on investors’ assessments of firm value, and that the announcement impact is higher after the 2012 revisions designed to strengthen the disclosure requirements. This is consistent with post-2012 JORC reports conveying higher information content. There continues to be information leakage prior to announcement date. Further tests show a widening of bid–ask spreads in the post-2012 period, suggestive of higher information asymmetry. While the probability of informed trading declines for large firms, it remains statistically unchanged for the rest of the sample. The findings reiterate the need for regulators and standard setters to be cognisant of unintended consequences of their decisions. The substantiation process under JORC involves a delay in the release of ‘news’, a ‘chilling’ effect with larger announcement effects.     

The social impact management plan as a tool for local planning: Case study: Mining in Northern Finland

The paper discusses social impact management plan (SIMP) as a planning tool for communities to continuously and adaptively manage and address the diverse social changes caused by mining developments. It introduces an empirical case study, where the SIMP is applied to deal with the possibilities and problems that the mining boom has created in a rural, sparsely populated municipality in Northern Europe. The making of the SIMP n the Sodankylä Municipality was the first community-led policy programme focused on mining in Finland. After collaborative planning with relevant stakeholders and political decision-making process, a SIMP laying out shared visions and mutually agreed actions was given the status of an official policy programme in 2018. However, there are several uncertainties related to the realization of the SIMP. From the viewpoint of governance dependencies, there are still differing opinions among the local stakeholders, including the mining companies, about what socially sustainable mining actually means and demands. Also, communities are often left with no other choice than to adapt to the interdependencies inherent in local governance, national legislation and politics. They also have to get used to international economic fluctuations and to the uncertainties intrinsic to the global production and consumption of metals. Nevertheless, the SIMP is a worthwhile effort to achieve the best local solutions related to mining in the northernmost parts of Europe.     

大数据驱动情景下企业跨边界知识网络生态系统建构

大数据驱动情景下企业跨边界知识网络研究日益受到各领域学者的关注，其中，生态系统建构是基础性问题。运用文本挖掘方法，基于杭州互联网企业的多案例调研，系统研究大数据驱动情景下企业跨边界知识网络生态系统建构问题。文本挖掘的故事线可提炼为“驱动→建构→跨越”，对应的两类关系路径分别是“大数据驱动情景→生态系统建构”和“生态系统建构→跨边界知识网络”。据此，得到集合互惠共生、开放协同、生态网络和价值治理4个主范畴理论模型，丰富了跨边界知识网络理论，并对企业生态系统构建具有指导价值。     

A Profit Function Approach to Wage–Risk Differentials

Abstract

A variable profit function is used in a novel way to estimate wage–risk premiums in Ohio bituminous coal mining. Unlike the dominant hedonic method, the profit function does not assume equilibrium and allows inferences about the marginal opportunity cost of accidents to mining companies. The profit function risk premium, expressed as a value of a statistical life (VSL), is $12,000 (in 1915 prices), and is below published estimates covering this period. The hedonic method is also used and yields a very similar VSL, a robustness check. It is also shown that the use of piece rate–based wages of coal loaders (the main group of miners) yields more plausible hedonic estimates than the fixed daily wage of “inside” miners typically employed.     

基于R语言主题模型的光伏产业创新政策层级性特征分析

以光伏太阳能产业为例，运用R语言主题模型，对国家、山西及大同3个层级政府2007—2019年光伏产业创新政策进行主题挖掘和量化分析，研究不同层级产业创新政策间的关联特征。结果表明：国家级政策主要集中于宏观价格管制和财政补贴制度，政策指导性特征明显；山西省级政策集中于中微观扶持性层面，政策指令性特征显现；大同市级政策主要集中于具体的微观运行机制，政策管控属性更加明显。上述政策特征与产业创新政策总体要求一致，但3个层级政策热门主题间还存在相关性不强、政策间互动影响作用不明显等问题，忽视了产业创新政策的传导渗透性特征。     

Analysis of the perceived value of online tourism reviews: Influence of readability and reviewer characteristics

Online reviews provide additional product information to reduce uncertainty. Hence, consumers often rely on online reviews to form purchase decisions. However, an explosion of online reviews brings the problem of information overload to individuals. Identifying reviews containing valuable information from large numbers of reviews becomes increasingly important to both consumers and companies, especially for experience products, such as attractions. Several online review platforms provide a function for readers to rate a review as “helpful” when it contains valuable information. Different from consumers, companies want to detect potential valuable reviews before they are rated to avoid or promote their negative or positive influence, respectively. Using online attraction review data retrieved from TripAdvisor, we conduct a two-level empirical analysis to explore factors that affect the value of reviews. We introduc a negative binomial regression model at a review level to explore the effects of the actual reviews. Subsequently, we apply a Tobit regression model at the reviewer level to investigate the effects of reviewer characteristics inferred from properties of historical rating distribution. The empirical analysis results indicate that both text readability and reviewer characteristics affect the perceived value of reviews. These findings have direct implications for attraction managers in their improved identification of potential valuable reviews.     

基于Logistic及文本分析的华北地下水漏斗区农户种植马铃薯意愿研究

[目的]对华北地下水漏斗区-河北地区的农户种植马铃薯的意愿及其影响因素,以及农户生产种植中遇到的问题进行定量与定性分析。[方法]基于149家马铃薯种植户的问卷调查,运用Logistic与文本分析方法进行研究。[结果]经定量分析表明,农业人口占家庭人口的比例、单位面积投入、土地使用情况、资金使用情况、马铃薯种植年限、单位面积产量以及销售渠道等这7个因素对农户种植马铃薯的意愿产生显著性影响;经文本分析发现,农户急切需要得到政府的帮助,特别是生产种植技术、补贴政策、机械化程度以及销售渠道等方面的援助。[结论]农业人口占家庭人口的比例越高,单位面积投入越高,土地使用以及资金使用越高,则农户种植马铃薯的意愿就越低;马铃薯种植年限越高,单位面积产量越高以及销售畅通,农户种植马铃薯的意愿就越高;农户的基本情况如农民的年龄与文化程度、家庭收入特征、用水情况、培训以及补贴状况等因素对马铃薯种植意愿的影响并不明显。     

煤炭资源采矿权随机便利收益估价模型

煤炭资源采矿权的有偿取得和转让是社会主义市场经济发展的客观必然,科学合理有效地对煤炭资源采矿权进行估价,是煤炭资源采矿权有偿取得和转让的关键和前提。煤炭资源采矿权具有和股票看涨期权一样的期权特性,本质上是一种按年度执行的多期看涨期权。便利收益的变动将直接影响煤炭资源采矿权价值,固定不变的便利收益或不考虑便利收益都不能准确地反映煤炭资源采矿权价值的变化。假定便利收益服从均值回复过程,文献[7]建立了便利收益和煤炭价格均随机变动的煤炭资源采矿权估价双因素模型,但该模型很难获得解析解,只能简化处理。本文界定了便利收益的内涵及其对煤炭资源采矿权价值的影响,运用鞅定价理论建立了基于随机便利收益的煤炭资源采矿权估价双因素模型,获得了解析解,并通过实例进行了运用,结果表明该模型较DCF方法和煤炭资源采矿权单因素模型更能体现资源所有者的权益。