Applied R in the Classroom

R, with support from a number of add-on packages, is an excellent teaching tool that can greatly enhance learning of exploratory data analysis (EDA) and linear regression. This article illustrates using R along with the packages tidyverse , GGally , esquisse and lindia to walk through an example of basic EDA and linear regression that might be used in an introductory class along with code examples for every step. Teaching with R can give learners control of their analysis, lower the intimidating coding barrier, and provide a platform on which to learn modeling and analysis.     

The institution efficiency of stock price limits： An experimental analysis on the two stocks market with continuous bid

Price limits in product market have been discarded in classic microeconomics. However, price limits affect the trade behavior of the same agent, since agents in the stock market change their trade status frequently. Due to the controversy on the institution effectiveness of the price limits in stock market, this paper design an experimental market with two stocks with continuous bid, in which we investigate the impact of the price limits on the stock market. The results show that the price limits moderate the price volatility within and between the trades periods, thus can stabilize stock price. In addition, price limits, when measured by traditional approach, restrain the fluidity of the market, reduce the volatility of transaction shares and maintain durative of fluidity. While volatility-based fluidity measurements show that the fluidity is enhanced significantly in stock market with price limits.     

模糊类比法在工程造价估算中的应用

工程造价的模糊估算方法是一种应用模糊数学的基本原理,对同一结构体系的拟建工程和已建工程结构方案的相似程序进行定量化对比和研究,从而快速地利用类似已建工程的造价资料估算拟建工程造价的方法。主要介绍该方法基本原理,并通过案例进行验证。     

Leader–member exchange and guanxi are not the same: differential impact of dyadic relationships on fit perceptions,helping behavior,and turnover intention

Extant literature on person–environment fit has underlined the positive impact of leader–member exchange (LMX) on person–supervisor (PS) fit. We challenge this assumption and propose that LMX, which captures the working relationship between employees and their managers, is more strongly associated with person–organization (PO) fit, not PS fit. We further propose that the personal aspect of the relationship between employees and their managers, namely supervisor–subordinate guanxi, is more strongly associated with PS fit than LMX. Finally, we theorize that LMX and supervisor–subordinate guanxi will be associated with turnover intention and helping behavior targeting the supervisor, respectively, through their differential impact on PO and PS fit. Data collected from 267 leader–member dyads in 17 companies in China using a two-wave procedure supported our hypotheses. These results have implications for theories on the multi-dimensional nature of the person–environment fit as well as research differentiating LMX and supervisor–subordinate guanxi.     

Updated trends in US brand-name and generic drug competition

Objective: To provide updated evidence on US trends in: market exclusivity periods (MEPs, time between brand-name drug launch and first generic competitors) for new molecular entities (NMEs); likelihood, timing and number of Hatch-Waxman Act Paragraph IV patent challenges; and generic drug penetration.

Methods: This study used IMS Health National Sales Perspectives^TM US data to calculate MEPs for the 288 NMEs experiencing initial generic entry between January 1995 and December 2014, the number of generic competitors for 12 months afterward (by level of annual sales prior to generic entry), and generic penetration rates. The likelihood, timing and number of Paragraph IV challengers were calculated using data from Abbreviated New Drug Approval (ANDA) letters, the FDA website, public information searches, and ParagraphFour.com.

Results: For drugs experiencing initial generic entry in 2013–2014, the MEP was 12.5 years for drugs with sales greater than $250 million (in 2008 dollars) in the year prior to generic entry ($250 million?+?NMEs), 13.6 years overall. After generic entry, brands rapidly lost sales, with their average unit share being 7% at 1 year for $250 million?+?NMEs, 12% overall. Ninety-four percent of $250 million?+?NMEs experiencing initial generic entry in 2013–2014 had faced at least one Paragraph IV challenge, an average of 5.2 years after brand launch (76% and 5.9 years for all NMEs). NMEs faced an average of 5.1 and 6.2 Paragraph IV challenges per NME, for all and $250 million?+?NMEs, respectively.

Limitations: Analyses, including Paragraph IV calculations, were restricted to NMEs where generic entry had occurred.

Conclusion: The average 2013–2014 MEP of 12.5 years for $250 million?+?NMEs, 13.6 overall remains consistent with prior research. MEPs are lower, and Paragraph IV challenges are more frequent and occur earlier for $250 million?+?drugs. Generic share erosion is also greater, and continues to intensify for both NME types.     

科技服务渗透对制造业技术进步的影响

利用世界投入产出表计算制造业细分行业科技服务渗透指数,在此基础上实证分析科技服务渗透对制造业技术进步的影响。结果表明：科技服务渗透促进了制造业技术进步,但作用强度不尽如人意;科技服务业的创新贡献在不同要素密集型制造业差异较大;本土科技服务与进口科技服务对制造业创新绩效都具有显著激励作用,且前者比后者的创新促进效应更显著;科技服务对制造业的创新激励存在明显的本地化效应,本土科技服务与进口科技服务在制造业创新过程中存在互补促进作用,需要进一步强化本土科技服务对进口科技服务的消化吸收再利用能力。     

科技人才组织领地行为如何影响其离职意向

基于资源保存理论视角,以科技人才为研究对象,关注其组织领地行为对离职意向的影响机制,并探究心理所有权的中介作用、婚姻的调节作用以及婚姻与心理所有权共同产生的被调节的中介作用。建立基于科技人才婚姻情况与心理所有权的被调节的中介作用模型,运用问卷调查方法收集全国各地高新技术企业、高等院校、科研院所等科技人才共411份有效问卷,展开实证分析。结果表明：不考虑婚姻的调节作用时,科技人才组织领地行为对离职意向的直接影响不显著,心理所有权对这种直接影响也无中介作用;考虑到婚姻的调节作用,未婚群体的组织领地行为越强,离职意向越强烈;在被调节的中介作用模型中,婚姻状况在心理所有权对组织领地行为与离职意向间的中介作用起到了调节作用,具体表现为未婚群体组织领地行为通过组织心理所有权的部分中介作用负向影响离职意向,通过直接影响机制正向影响离职意向。     

极化理论视角下我国金融发展的区域比较

我国金融业快速发展,但各地区金融发展的要素禀赋存在较大差异。如何从国家战略角度解决金融发展布局问题,需要深入思考。本文利用极化理论进行研究,首先通过主成分分析方法设计了我国金融发展综合指数。在此基础上,运用Esteban-Ray指数的原理构造了金融发展极化指数,依据该指数对我国金融发展极化情况进行考察。分析发现我国金融发展极化现象已经出现,并且极化速度较快,金融极化与经济极化表现出较强的负相关关系。通过对东中西部三大区域的极化趋势进行比较,发现东部地区与中西部地区的极化特点有较大差异,据此文章提出了相应的政策建议。     

工会提高了员工福利和企业效率吗?——来自第一次全国经济普查的微观证据

中国拥有世界上规模最为庞大的工会组织,承担着增进社会福利和维护员工利益的双重职能,但先前对工会作用的研究定性分析较多、定量研究较少。本文运用第一次全国经济普查25万多家企业的数据进行实证研究,结果发现:(1)无论是运用工会虚拟变量还是工会人数占比作为解释变量,工会都与企业的劳动生产率、全要素生产率和培训费用负相关,与人均工资、三险一金和福利费正相关;(2)通过工会经费获取能力筛选出"活跃工会"子样本进行稳健性检验,也得到了相同的结论。这说明我国工会已经显著履行了提升职工福利的职能,未来发展中我国工会还应当积极参与企业管理、提升企业效率。     

成都市知识产权联盟发展路径研究

自国务院实施知识产权战略以来,知识产权作为推动科技创新的重要力量越来越得到社会各界的重视。知识产权联盟的发展,是深入推进知识产权战略的重要抓手之一。成都是全国首批知识产权示范城市,有发展知识产权联盟的较好基础。从技术转移联盟,细分产业知识产权联盟和产业园区知识产权服务联盟三个层面多种形式,构建起城市完整的知识产权联盟体系,将对成都市的知识产权工作带来新的机遇和挑战。