Information flow between prediction markets,polls and media: Evidence from the 2008 presidential primaries

Are the forecast errors of election-eve polls themselves forecastable? We present evidence from the 2008 Democratic Party nomination race between Barack Obama and Hillary Clinton showing that the answer is yes. Both cross-sectional and time series evidence suggests that market prices contain information about election outcomes that polls taken shortly before the contests do not. Conversely, election surprises relative to polls too Granger cause subsequent price movements. We then investigate whether the additional information in prices could come from the media coverage of these campaigns, and uncover a set of complex relationships between pollster’s surprise, price movements, and various aspects of media coverage. Prices anticipate the balance and content of media coverage, but not the volume. On the other hand, it is the volume of media coverage, not the balance or content, that anticipates the surprise element in election outcomes. Moreover, Granger causality between prices and election surprises barely changes after controlling for media coverage, and causality from media volume to surprises persists too after controlling for price movements. Taken together, the results suggest that both prices and the volume of media coverage contain independent election-relevant information that is not captured in polls.     

Some issues in blockchain for accounting and the supply chain,with an application of distributed databases to virtual organizations

This paper reviews some recent blockchain‐based applications for information capture, distribution and preservation. As part of that review, this paper examines two key concerns with current blockchain designs for accounting and supply chain transactions: data independence and multiple semantic models for the same information distribution problem. Blockchain applications typically integrate database, application and presentation tiers all in the same ledger. This results in a general inability to query information in the ledger and other concerns. Further, since most applications appear to be private blockchain applications, there is a concern of agents needing to accommodate multiple blockchains depending on who their trading partners are and what they request. Finally, this paper uses a distributed database to design a ‘blockchain‐like’ system for virtual organizations.     

Simulated economic impacts in applied trade modelling: A comparison of tariff aggregation approaches

This paper assesses the performance of two recently developed tariff aggregators in reducing tariff aggregation bias by analysing Swiss beef market liberalisation scenarios. Specific relevant sources of bias are addressed: substitution effects on import demand, Tariff Rate Quotas and overprotection in tariffs. The aggregators are linked to a global large-scale partial equilibrium model and benchmarked against a standard aggregator. The choice of the aggregation method shows considerable effects on simulated economic impacts, specifically if the dispersion in tariffs or tariff cuts is large. A large bias is revealed in simulated gains from trade liberalisation using the standard aggregator. The impacts on traded quantities are found to be overestimated, while price and welfare effects can be higher or lower by switching to alternative aggregation methods. By reducing aggregation bias and depicting negotiated tariff schedules more directly, the proposed aggregators enhance the contribution of trade modelling to evidence-based policy making.     

网络节点特征与城市绿色创新效率提升——基于节点枢纽性与节点聚集度视角

随着城市间创新联系的持续增强,城市创新网络的优化与发展对城市绿色创新效率的促进作用日益凸现。部分研究考察了城市绿色创新效率的空间溢出效应和城市创新网络特征的影响,但鲜有文献关注城市的网络节点特征对其绿色创新效率的影响,尤其缺乏相应的经验分析。本文认为,在城市创新网络中各个城市即网络中的节点,创新资源和活动在节点的聚集产生规模效应,创新资源和活动在节点间流动则带来溢出效应,两者都有利于城市绿色创新效率的提升。因此,反映节点在网络联系中重要性的节点枢纽性和反映网络中不同节点聚集成团程度的节点聚集度提高,均有利于城市绿色创新效率的提升。节点枢纽性的提高对城市自身的基础设施建设提出更高要求,因而可以通过改善基础设施的路径促进城市绿色创新效率提升;节点聚集度的提高为城市金融发展带来更多的需求和机会,因而可以通过增加创新投融资规模的路径促进城市绿色创新效率提升。在城市密度和经济发展水平较高的地区,城市间的创新联系较便利,节点枢纽性提高对城市绿色创新效率提升的促进作用较大;而在城市密度和经济发展水平较低的地区,创新聚集的效率相对较高,节点聚集度提高对城市绿色创新效率提升的促进作用较大。以2010—2018年中国279个城市为样本,通过引力模型构建城市创新网络,进而测度节点枢纽性和节点聚集度,分析发现：节点枢纽性和节点聚集度对城市绿色创新效率具有显著正向影响;城市交通基础设施在节点枢纽性促进城市绿色创新效率中具有显著的部分中介效应,城市金融机构存款水平在节点聚集度促进城市绿色创新效率中具有显著的遮掩效应;节点枢纽性对城市绿色创新效率的促进效应在东、中、西部地区依次减弱,而节点聚集度的促进效应依次增强。相比已有文献,本文主要从三个方面进行了拓展和深化：一是从网络节点特征角度拓展城市绿色创新效率的影响因素研究,二是从影响路径和区域异质性层面深化网络节点特征影响创新效率的机制研究,三是为通过改善网络节点特征促进绿色创新效率提升提供经验证据。本文揭示了城市创新网络进化（节点枢纽性与节点聚集度提高）对绿色创新效率提升的重要作用及其影响路径和区域异质性,有利于在新发展阶段通过优化城市网络发展格局进一步促进创新发展和绿色发展。     

论幽默语言的模糊性

幽默语言是理解层面上的模糊语言，它同模糊语言学中所讨论的既有原型、又有边缘情况的模糊语言是不同的，其模糊性更多地体现在语境的模糊上，语义解释也强烈依赖语境的暗示。而模糊语言学中的模糊语言的产生来源于人类思维的模糊或事物本体的模糊，其实质是概念的不确定性，由词语的语义模糊体现，该模糊性是不能在语境中消除的。模糊语言在语义上的分类有助于人们更好地理解幽默语言。     

构建现代旅游资源产权制度与旅游业可持续发展能力研究

“可持续发展”与“可持续发展能力”是有差异的,“可持续发展能力”是一个国家或地区为实现这种发展需求所具备的支付能力。根据环境经济学原理,运用可持续发展理论、产权理论,从理论与实践相结合的角度分析论证政府与旅游资源资产化形成的“聚合力”是旅游业可持续发展能力的“支付能力”,经济系统是旅游业可持续发展的能力的供给者。     

哈尔滨产业集聚化存在的问题及对策研究

产业集聚以其无可比拟的竞争优势,成为振兴哈尔滨老工业基地首要的战略模式选择。哈尔滨要实现老工业基地振兴的目标,不仅需要国家政策的支持,更需要依靠市场机制,利用本地优势产业的基础和资源禀赋,通过优势产业的集群规模效应,提高城市核心竞争力,促进全市产业结构的调整及产业集聚化的发展,实现振兴老工业基地的目标。     

Incorporating heterogeneity with store-level aggregate data

This paper introduces a methodology to incorporate heterogeneity in the analysis of store level aggregate data. The proposed model is validated using two sets of scanner panel data, for tuna and ketchup, and their corresponding weekly aggregate data. The model recovers the true parameters with acceptable accuracy.The model has several advantages over the previous aggregate models, such as the linear model, the semilog model, and the log-log model. First, the cross-price elasticities estimated from the model show the asymmetric responses to the price promotions very close to those from the logit model applied to the panel data. Second, the model shows better prediction performance.     

频繁子图在监控系统数据挖掘中的应用

监控系统数据挖掘研究近年来受到了国内外学者的逐渐关注,监控系统数据挖掘是发现基于视频原始底层数据对应于应用层的语义信息关联及对应关系。视频底层数据特征十分复杂,沿用传统数据挖掘思想去理解和看待监控系统数据挖掘还不够。与一般的数据比较,图能够表达更加丰富的语义。把监控系统视频数据转化为图模型,将频繁子图挖掘算法应用到监控系统语义挖掘中,提出一种新的监控系统语义挖掘方法,与现有的方法相比较,该方法具有有效性和可行性。