市场结构、效率与证券业绩效——基于动态面板数据模型的分析

利用我国证券公司2009-2013年数据建立动态面板数据模型,分析证券业的市场结构、效率与绩效的关系.研究表明:我国证券行业竞争激烈,但市场份额具有较强的持续性.结构绩效(SCP)假说与相对市场力量(RMP)假说得到证实,但效率结构(RS)假说以及平静生活假说(QL)没有得到支持.市场集中度提升有利于培育出盈利能力强、具有国际竞争力的证券公司;市场份额的提升则提高了证券公司的纯技术效率.目前证券行业兼并行为,从政府政策的层面不应作出限制.     

减排约束下中国天然气供需安全评价:2006-2014年

为准确把握中国天然气供需安全状态,以2006-2014年的数据为样本,在模糊隶属度函数量化指标值的基础上,运用层次分析法(AHP)和熵值法确定指标权重,基于线性加权和函数计算均方根进行综合评价。结果表明:(1)中国天然气供需安全指数呈现"N形"波动,2006-2007年天然气供需安全指数上升。2007-2013年天然气供需安全指数年均下降1.7979。2013年以来天然气供需安全指数开始回升,天然气供需安全压力有所缓解。(2)天然气供应安全指数从2006年的17.5914下降到2013年的0.1556,峰谷差17.4359。天然气需求安全指数呈现"W形"波动。天然气市场安全指数相对稳定,2013年以来略有上升,天然气市场风险逐年下降。(3)天然气供需安全很大程度上取决于天然气供应是否安全。因此,建议从确保天然气稳定供应、提高天然气使用效率和降低市场风险方面采取措施,维护天然气供需安全。     

WTO巴厘一揽子协定粮食安全条款谈判:背景、进展与对策

巴厘一揽子协定为中国保障粮食安全带来了新局面。从关税及贸易总协定、乌拉圭至多哈回合时期,粮食安全关注越来越成为谈判的重点,多哈回合谈判中各大利益集团也就其自身情况表明不同的谈判立场及利益诉求。协定的达成,在确认粮食安全等非贸易关注的重要意义、公共储备计划的"和平条款"、关税配额制度改革等方面实现突破的同时,又存在文件约束力低下、取消发达国家农产品补贴目标失败、利好政策实施程序及条件复杂等缺憾。对于中国而言,应分析此次协定为增强中国的粮食获取能力带来的政策利好,继续在后续谈判中加强对粮食安全的关注,同时及时地修改中国的粮食安全相关法律法规。     

试论列宁关于避免执政危险的思想

政党执掌政权只有避免执政危险,才能长久地确保执政地位。十月革命胜利之后,列宁就已经开始思考如何避免执政危险的问题,他深刻地认识到俄共（布）执政面临着急躁冒进的危险、脱离群众的危险、能力不足的危险以及被俄国旧文化所征服的危险。列宁对如何避免这些执政危险进行了初步的思考和探索,并采取了一系列措施,巩固了俄共（布）的执政地位。     

美国粮食价格突变及其对国内农业安全的启示

美国粮食市场价格突变可能为我国农业安全带来不可估量的冲击。以玉米和大豆产业为例,选取2000—2013年季度价格相关数据,基于PPM模型识别了玉米和大豆价格突变节点并测算其形成原因。实证结果显示,自21世纪以来,全美玉米市场共发生了六次价格上升突变、两次价格下降突变;大豆市场则历经四次价格上升突变、两次价格下降突变。粮价突变是供需因素与国际贸易、原油价格、美元指数变动等众多非供需因素共同作用的结果,因所处政治经济背景不同,各阶段形成原因也不尽相同。分析表明,美国粮价突变首先通过价格信息与贸易渠道间接的影响国内玉米和大豆价格;然后经由其他农产品价格波动、短期供给波动、国际游资及外商控制等路径对国内农业安全带来威胁。     

Some maximum-indifference estimators for the slope of a univariate linear model

As known, the least-squares estimator of the slope of a univariate linear model sets to zero the covariance between the regression residuals and the values of the explanatory variable. To prevent the estimation process from being influenced by outliers, which can be theoretically modelled by a heavy-tailed distribution for the error term, one can substitute covariance with some robust measures of association, for example Kendall's tau in the popular Theil–Sen estimator. In a scarcely known Italian paper, Cifarelli [(1978), ‘La Stima del Coefficiente di Regressione Mediante l'Indice di Cograduazione di Gini’, Rivista di matematica per le scienze economiche e sociali, 1, 7–38. A translation into English is available at http://arxiv.org/abs/1411.4809 and will appear in Decisions in Economics and Finance] shows that a gain of efficiency can be obtained by using Gini's cograduation index instead of Kendall's tau. This paper introduces a new estimator, derived from another association measure recently proposed. Such a measure is strongly related to Gini's cograduation index, as they are both built to vanish in the general framework of indifference. The newly proposed estimator is shown to be unbiased and asymptotically normally distributed. Moreover, all considered estimators are compared via their asymptotic relative efficiency and a small simulation study. Finally, some indications about the performance of the considered estimators in the presence of contaminated normal data are provided.     

基于LW估计的中国证券市场长记忆性实证研究

针对国内研究证券市场长记忆性主要采用的是时域方法,文章采用基于频域的半参数Local Whittle估计方法研究了中国证券市场的长记忆特性,并且和对数周期图回归(GPH)方法进行了比较。结果表明,LW方法具有不受时间频率的影响,能够有效消除时间序列中短期记忆和周期性对估计结果的影响等优点,明显优于GPH方法。实证结果表明,中国证券市场存在明显的长记忆性,并且长记忆行为在重大突发事件发生期间更加明显。文章还从长记忆的角度探讨了“政策市”的存在性和相关特点。     

失地农民权益保障的制度创新

农业用地转为建设用地是工业化和城市化进程中的必然现象.虽然我国政府对失地农民进行了补偿,但由于土地产权制度、土地征用制度以及社会保障制度的不完善,致使失地农民仍然蒙受着经济权益的损害、政治权益的剥夺和社会权益的缺失.因此,制度创新是保障失地农民权益的有效途径.应改革土地产权制度,明确集体土地所有权主体,健全农民承包经营权权能;完善土地征用制度,限定"公共利益"的范围,提高征地补偿标准,严格规范征地程序;建立健全失地农民的养老、医疗、最低生活保障制度和就业保障机制.     

Connecting the gendered door: women, violence and doorwork

This paper explores the emerging role of women who work as 'bouncers', or doorstaff, in the night-time economy and examines how the cultural capital of the female bouncer is connected to the methods utilized to control licensed premises. It is drawn from a study that combined ethnographic observations and interviews in five major UK cities which explored a diverse range of issues such as gendered bodies, femininities and violence; the changing needs of the night-time economy in the UK and the experiences of women engaged in 'non-traditional' occupations. In this paper, we draw on interview data with one particular category of female door staff; women who share similar histories of exposure to violence and violent cultures, and we examine how their experiential knowledge of violence equips them with the resources to 'work the doors'. Our attention focuses on this group of women, who we refer to as 'The Connected', and examine how they are 'doing gender' when they negotiate violence 'on the door'     

The West,Russia, and China in Central Asia: What Kind of Game Is Being Played in the Region?

The article discusses the nature of the tangled interaction between the ex-Soviet Central Asian republics and the outside great powers – Russia, the United States and China. Although the so-called Great Game model is often used to explain the geopolitical rivalry in the region, the current pattern of relations between various international actors is much more complex than a traditional tug-of-war between the old colonial empires. While Russia's strategic role in Central Asia appears to be on the rise, the capacity of the West to influence political developments in the region has diminished. However, the overall situation in Central Asia remains volatile and its geopolitical landscape is far from being settled.