市场结构内生变迁与产能过剩治理

本文构建了一个市场需求不确定性情况下的企业动态性模型,发现当行业发展前景相对确定但市场需求存在较大不确定性时,高效率企业为规避风险会谨慎投资,从而为大量低效率企业留下市场空间,市场集中度和产能利用率较低。而随着行业成熟和不确定性减少,优势企业会不断扩大规模,逐步淘汰劣势企业,最终形成较合理的市场结构和产能利用率。因而,我国一些重要行业在早期发展阶段出现大量企业涌入的现象,不应片面视为市场失灵,也不能一概归因于地方政府的产业扶持政策。本文以我国家电和钢铁产业为例,说明治理产能分散和过剩问题,根本办法是建立和维护公平竞争的市场环境,让市场内生的产能集中机制更好地发挥作用,而不是"以扭曲去对付扭曲"。     

旅游业大发展背景下导游高流失率的悖谬:导游离职影响因素分析

在旅游业如火如荼大发展的光环下,身处第一线的导游人员群体却面临着非常尴尬的处境,其流失率远高于其他职业。本文从问卷调研的实证角度,通过因子分析、相关分析等方法,得到影响导游流失的因子有晋升、薪酬、WIF、FIW、FVSW、职业疲劳,在此基础上提出完善导游管理服务中心机制功能的导游服务外包措施。研究成果拓展了导游流失研究范畴,丰富了其理论意义上的内涵和外延;同时,明晰了导游流失的症结,提出了缓解对策。     

国际油价冲击与中国的经济增长——基于非对称关系视角的分析

本文基于季度数据，引入非对称协整模型，考察国际油价与中国经济增长的动态关系，并鉴于油价波动对不发达经济体可能的冲击，还测度了油价的不确定性并探析其对经济增长的影响，结果表明：（1）从短期来看，国际油价变化是国内经济增长的单向Granger原因，“中国因素”对全球油价变化的影响尚不明显；（2）从长期来看，国际油价和经济增长具有非对称协整关系，油价上涨对经济的影响明显大于油价下跌所产生的效应；（3）国际石油市场存在正反馈交易行为，导致油价波动在油价上涨时表现更加明显。油价不确定性在短期内对经济增长存在负面影响，长期中则不会显著影响经济增长。以上结果意味着必须高度重视石油安全问题，加强油价波动预警与风险管理系统。     

A principal component model for forecasting age- and sex-specific survival probabilities in Western Europe

The assessment of future mortality is of high importance in many areas where the allocation of future resources has to be planned in time, especially in social security and private life insurance. This contribution represents an extension of the classic forecasting approaches of Bell–Monsell and Lee–Carter. Based on a forecast of the first two principal components, age- and sex-specific survival probabilities for 18 Western European countries are predicted simultaneously until the year 2070. In addition to the correlations in the mortality trends between the age groups and the genders, international trends in mortality are captured as well. A major improvement in the classic Lee–Carter models is the adequate quantification of the uncertainty associated with the whole system of variables by stochastic simulation of all remaining principal components with simple time series models. The model’s easy applicability to further analyses is illustrated by forecasting the median life span as well as the resulting Gender Gap for Germany, France, and Italy.     

The Empire Strikes Back: Digital Control of Unfair Terms of Online Services

The authors argue that it is possible to partly automate the process of abstract control of fairness of clauses in online consumer contracts. The authors present a theoretical and empirical argument for this claim, including a brief presentation of the software they have designed. This type of automation would not replace human lawyers but would assist them and make their work more effective and efficient. Policy makers should direct their attention to the potential of using algorithmic techniques in enforcing the law regarding unfair contractual terms, and to facilitating research on and ultimately implementing such technologies.     

Variable selection for varying coefficient models with measurement errors

This paper focuses on variable selections for varying coefficient models when some covariates are measured with errors. We present a bias-corrected variable selection procedure by combining basis function approximations with shrinkage estimations. With appropriate selection of the tuning parameters, we establish the consistency of the variable selection procedure, and derive the optimal convergence rate of the regularized estimators. A simulation study and a real data application are undertaken to assess the finite sample performance of the proposed variable selection procedure.     

Issues in the analysis of co-authorship networks

Scientific collaboration is a complex phenomenon that improves the sharing of competences and the production of new scientific knowledge. Social Network Analysis is often used to describe the scientific collaboration patterns defined by co-authorship relationships. Different phases of the analysis of collaboration are related to: data collection, network boundary setting, relational data matrix definition, data analysis and interpretation of results. The aim of this paper is to point out some issues that arise in these different phases, highlighting: (i) the use of local archives versus international bibliographic databases; (ii) the use of different approaches for setting boundaries in a whole-network; (iii) the definition of a co-authorship data matrix (binary and weighted ties) and (iv) the analysis and the interpretation of network measures for co-authorship data. We discuss the different choices that can be made in these phases within an illustrative example on real data which is referred to scientific collaboration among researchers affiliated to an academic institution. In particular, we compare global and actor-level network measures computed from binary and weighted co-authorship networks in different disciplines.