Data-driven tree structure for PIN models

Probability of informed trading (PIN) models characterize trading with certain types of information through a tree structure. Different tree structures with different numbers of groups for market participants have been proposed, with no clear, consistent tree used in the literature. One of the main causes of this inconsistency is that these trees are artificially proposed through a bottom-up approach rather than implied by actual market data. Therefore, in this paper, we propose a method that infers a tree structure directly from empirical data. More precisely, we use hierarchical clustering to construct a tree for each individual firm and then infer an aggregate tree through a voting mechanism. We test this method on US data from January 2002 for 7608 companies, which results in a tree with two layers and four groups. The characteristics of the resulting aggregate tree are between those of several proposed tree structures in the literature, demonstrating that these proposed trees all reflect only part of the market, and one should consider the proposed empirically driven method when seeking a tree representing the whole market.

     

Comparative persistence and adherence with newer anti-hyperglycemic agents to treat patients with type 2 diabetes in the United States

Objectives: Non-adherence and non-persistence to anti-hyperglycemic agents are associated with worse clinical and economic outcomes in patients with type 2 diabetes. This study evaluated treatment persistence and adherence across newer anti-hyperglycemic agents (canagliflozin, dapagliflozin, sitagliptin, saxagliptin, linagliptin, liraglutide, or exenatide).

Methods: This retrospective cohort study of Truven Health Analytics Marketscan databases included adult patients with type 2 diabetes whose first pharmacy claim for a newer anti-hyperglycemic agent was between February 1, 2014 and July 31, 2014. Treatment persistence and adherence were assessed for 12 months after the first claim (post-index). Persistence was defined as no gap ≥90 days between the end of one pharmacy claim and the start of the next pharmacy claim post-index. Adherence used two definitions: proportion of days covered (PDC) and medication possession ratio (MPR). Multivariable analyses of non-persistence (hazard ratios) and adherence (odds ratios) were adjusted for baseline demographics, drug cost, clinical characteristics, and other anti-hyperglycemic agents.

Results: A total of 11,961 patients met all study selection criteria. Persistence rates at 12 months were significantly greater (p?p?=?0.83; PDC?=?0.79) and canagliflozin 300?mg (MPR?=?0.92; PDC?=?0.81) were greater than for the other index anti-hyperglycemic agents (MPR?=?0.33–0.75; PDC?=?0.33–0.72). Consistent results for treatment persistence and adherence were observed in multivariable analyses that were adjusted baseline characteristics.

Conclusions: Canagliflozin was associated with better treatment persistence and treatment adherence compared with other anti-hyperglycemic agents in real-world settings.     

Timing earnings

Since the opening of China’s securities market, there have been a number of bull and bear cycles. This paper discusses how executives use the market timing approach to manage earnings in different cycles to maximize firm value. We find that Chinese listed companies choose to release more earnings during bull markets and this phenomenon is more evident in companies that are more profitable and have higher valuations. We also find that executives who do not release more earnings during bull markets are more likely to be dismissed.     

UGC的表现形式对网络营销效果的影响研究——以微博为例

随着Web2.0的兴起,用户创作内容（UGC）的概念应运而生,迅速发展并逐渐成为供应商组织生产、商家营销宣传以及消费者购买产品的利器.本论文梳理了UGC相关研究的分类和趋势,并选择微博作为平台,采用情景实验法,探究UGC的表现形式（文本、图片、音视频）对网络营销效果的影响,在此基础上为企业进行更大范围的社会化媒体营销（如博客、SNS社区等）提供策略性建议与营销思路,有效提升UGC互动的效用,在理论和实际应用上都有着显著意义.     

How group efficacy mediates the relationship between group affect and identification

This study examines the mediating role of group efficacy on the relationship between group affect and group identification by integrating the collective cognition process. Using a sample of forty-seven work groups in Study 1, the results show that group efficacy fully mediates the relationship between positive and negative group affect and group identification. Study 2 applies a two-wave panel design to verify the impact of group efficacy on group identification. The results of Study 2 indicate that group efficacy relates positively to the development of group identification. The implications for theory and practice are discussed.     

KIBS企业—顾客交互创新中知识整合的权变机制

引入过程互依性和项目不确定性,探讨了KIBS企业-顾客交互创新中知识整合的权变机制。基于338份服务创新项目问卷数据进行实证研究,结果显示:在KIBS企业-顾客交互四要素中,除规则正式化负向影响外部知识整合以外,决策集体化、资源共享和任务协作均正向影响内、外部知识整合;过程互依性增强了规则正式化、决策集体化和任务协作对内部知识整合的影响,但对资源共享与内部知识整合间关系的调节作用不显著;项目不确定性增强了规则正式化、资源共享和任务协作对外部知识整合的影响,但对决策集体化与外部知识整合间关系的调节作用不显著。     

企业政治关联对风险投资引入方式的影响

从资金需求方出发，以2009年10月至2016年12月深圳创业板和中小板首次公开上市的公司为样本，实证检验了政治关联对风险投资引入方式的影响，以及激励机制和监督机制这两种公司治理机制的调节作用，得到结论如下：政治关联企业倾向于在发展后期引入风险投资；政治关联企业倾向于选择国有性质、经验丰富以及参与程度高的风险投资机构；激励机制会加强政治关联企业在发展后期引入风险投资以及选择国有性质、经验丰富、参与程度高的风险投资机构的意愿；监督机制会减弱政治关联企业在发展后期阶段引入风险投资以及选择国有性质、经验丰富、参与程度高的风险投资机构的意愿。结论对拓展政治关联与风险投资领域的理论和实践具有重要启示意义。     

食物淀粉性质结构的研究进展

随着种类繁多的食物淀粉通过不同方式逐渐走进大众的视野,引发了研究者们对食物淀粉使用多样化方面探究的高度关注。对食物淀粉进行深加工是提高淀粉价值的有效途径,但在其加工过程中,为保证最终产品的高附加值及稳定的优良品质,就必须通过合适的手段选择出适用于深加工的食物品种。本文综述了近年来在食物淀粉方面的研究概况,着重对食物淀粉理化性质及结构方面作简要阐述。     

财务报告问询函压力与企业金融化

企业遭遇非处罚性监管后,在金融资产配置上会作何调整以适应压力情境下自身的投融资需要呢?本文基于交易所发放财务报告问询函的实证研究发现:财务报告问询函会提升上市公司金融资产配置水平,并且短期金融资产增长更快.进一步,问询函中即使涉及金融资产问题,企业金融化水平仍会提高;压力情境下,企业金融化内在的真实动机在于发挥"蓄水池"作用,融资约束发挥了部分中介机制.最后,遭遇问询的实体企业通过"盲目"的金融化并没有改善整体业绩,却损害了未来主营业绩.本文从企业金融化视角对非处罚性监管的经济后果研究形成有益补充,同时对强化证券交易所一线监管职能,关注重点企业"脱虚向实"问题提供了新思路.     

Economic evaluation of human urinary kallindinogenase for patients with acute ischemic stroke in China

Objectives: In China, both human urinary kallindinogenase (HUK) and 3-n-butylphthalide (NBP) are recommended for clinical use to improve cerebral blood circulation during an acute ischemic stroke (AIS). The objective was to evaluate the economic value of HUK vs NBP for patients with AIS from a Chinese payer’s perspective.

Methods: An economic evaluation based on data of patients who have been treated with either HUK (n?=?488) or NBP (n?=?885) from a prospective, phase IV, multi-center, clinical registry study (Chinese Acute Ischemic Stroke Treatment Outcome Registry, CASTOR) was conducted to analyze the cost and effectiveness of HUK vs NBP for AIS in China. Before the analysis, the patients were matched using propensity score. Both a cost-minimization analysis and a cost-effectiveness analysis were conducted to compare the matched pairs. A bootstrapping exercise was conducted for the matched arms to demonstrate the probability of one intervention being cost-effective over another for a given willingness-to-pay for an extra quality-adjusted life-year (QALY).

Results: After propensity score matching, 463 pairs were matched. The overall medical cost in the HUK arm is USD 2,701.20, while the NBP arm is USD 3,436.83, indicating HUK is preferred with cost-minimization analysis. Although the QALY gained in the HUK arm (0.77176) compared with the NBP arm (0.76831) is statistically insignificant (p?=?.4862), the cost-effectiveness analysis as exploratory analysis found that, compared with NBP, HUK is a cost-saving strategy with the lower costs of USD 735.63 and greater QALYs gained of 0.00345. Among the 5,000 bootstrapping replications, 100% indicates that HUK is cost-effective compared with NBP under a 1-time-GDP threshold; and 97.12% indicates the same under a 3-time-GDP threshold.

Conclusion: This economic evaluation study indicates that administrating HUK is a cost-saving therapy compared with NBP for managing blood flow during AIS in the Chinese setting.