Asymptotic subadditivity/superadditivity of Value-at-Risk under tail dependence

This paper presents a new method for discussing the asymptotic subadditivity/superadditivity of Value-at-Risk (VaR) for multiple risks. We consider the asymptotic subadditivity and superadditivity properties of VaR for multiple risks whose copula admits a stable tail dependence function (STDF). For the purpose, a marginal region is defined by the marginal distributions of the multiple risks, and a stochastic order named tail concave order is presented for comparing individual tail risks. We prove that asymptotic subadditivity of VaR holds when individual risks are smaller than regularly varying (RV) random variables with index −1 under the tail concave order. We also provide sufficient conditions for VaR being asymptotically superadditive. For two multiple risks sharing the same copula function and satisfying the tail concave order, a comparison result on the asymptotic subadditivity/superadditivity of VaR is given. Asymptotic diversification ratios for RV and log regularly varying (LRV) margins with specific copula structures are obtained. Empirical analysis on financial data is provided for highlighting our results.     

不同生计模式下六盘山区易地扶贫搬迁移民生计资本耦合协调研究——以甘肃省古浪县为例

[目的]探究易地扶贫搬迁移民的生计耦合协调有助于全面了解移民的生计问题,对提高移民可持续生计能力及后续发展提供参考。[方法]文章以甘肃省古浪县易地扶贫搬迁家庭为研究对象,通过2019—2021年实地访谈和问卷调查等方法对移民家庭的生计状况进行调查,选取测度指标并计算各类移民的生计资本值,根据移民收入来源对生计模式进行分类,运用耦合协调度模型分析各生计模式下移民5项生计资本间的关系。[结果]（1）生计资本内部耦合水平总体较低,处于低度耦合和失调衰退等级;（2）非农型的生计资本耦合度和协调度最高,分别为0.299和0.230,是最为接近中度耦合和过渡协调阶段的生计模式;（3）两类兼业户的次之,处在（0.15,0.3）的区间内,属于低度耦合和衰退协调的中高级阶段;（4）纯农户的较低,为0.172和0.223,处于低度耦合和协调衰退的中阶段;（5）补贴户的最低,耦合度、协调度均在（0,1）的区间,处在低度弱耦合和恶性失调等级。[结论]古浪县不同生计模式下易地扶贫搬迁移民的生计资本存量和差距,导致其耦合协调性较差、差异较大。     

国家高新区能否提升城市创新水平?

文章基于2003年至2016年我国215个城市面板数据，运用双重差分模型、空间双重差分模型和分位数回归模型等方法，实证检验了国家高新区对城市创新水平的影响及其空间异质性特征。研究结果表明，国家高新区建设显著提升了城市创新水平，并且高新区设立带动的城市投资集聚是推动城市创新水平提升的重要原因。空间双重差分结果表明，国家高新区对城市创新水平的提升作用并非源于其对周边城市创新资源的掠夺，相反高新区设立对周边城市和省内城市均产生了显著的溢出效应，提升了本省城市和周边外省城市创新水平。此外，国家高新区对城市创新水平的影响具有空间异质性特征，在省会城市、直辖市和副省级城市，高新区对城市创新水平的影响并不显著，而能够显著提升一般地级市创新水平；随着城市创新水平的提升，高新区建设对城市创新水平的促进作用呈现出先增强、后减弱直至不再显著的非对称"倒V型"变化特征。但是研究也发现，国家高新区对城市创新水平影响的区位异质性并不显著，高新区对东部地区和中西部地区城市创新水平提升均具有显著的促进作用。     

A comparison of Ad valorem and per unit taxes in regulated monopolies

This paper compares the output and revenue effects in the rate-of-return regulated monopoly model. Both the ad valorem and the unit tax generally decrease the use of capital, and as such, reduce the output and raise the price. In addition, it is shown that Suits and Musgrave's conclusion of higher revenue of an ad valorem tax at a given output can apply to a regulated monopolist if the marginal product of labor under the ad valorem tax is greater than or equal to that under the unit tax. Similarly, their second conclusion, that for a given tax revenue an ad valorem tax has a larger output than a unit tax rate before the revenue-maximizing tax rate, can also apply to the regulated monopolist.     

商业银行的操作风险、声誉效应与市场反应

我们通过比较银行市场价值损失与发生操作风险造成的损失的差异来分离出纯声誉效应,并实证分析了该声誉效应对不同银行及损失事件不同阶段的市场收益率的影响的差异。研究发现,操作风险事件在不同时期会产生迥异的市场反应。在披露期,银行遭受损失时会出现显著为负的异常收益率,在结算期却出现显著为正的异常收益率,而在承认期,该效应却并没有表现出一定的规律性;且上述声誉效应造成市场收益率的动态变化在不同类型的银行差异明显。这也启示我们,声誉效应的存在使银行有必要对操作风险造成的损失进行有效控制以及适时回应事件中的不确定信息。这将有助于减少银行的损失及保持市场的稳定。     

Corporate Lobbying and Firm Performance

Corporate lobbying activities are designed to influence legislators, regulators and courts, presumably to encourage favorable policies and/or outcomes. In dollar terms, corporate lobbying expenditures are typically one or even two orders of magnitude larger than spending by Political Action Committees (PAC), and, unlike PAC donations, lobbying amounts are direct corporate expenditures. We use data made available by the Lobbying Disclosure Act of 1995 to examine this more pervasive form of corporate political activity. We find that, on average, lobbying is positively related to accounting and market measures of financial performance. These results are robust across a number of empirical specifications. We also report market performance evidence using a portfolio approach. We find that portfolios of firms with the highest lobbying intensities significantly outperform their benchmarks in the three years following portfolio formation.     

浅谈我国政府会计财务风险防范

随着社会主义市场经济体制发展,我国政府职能转变和财政体制改革的不断深化,现行的政府会计的财务负债风险和投资失败风险都日益增大.这就要求我们要不断推进政府会计改革,注重政府财务风险的防范.     

试论房地产企业避税行为的会计思考

近年来房地产行业的发展是有目共睹的,纵观这一栋栋商品房的价格就可以得出很明确的结论,房地产确实对国民生产总值的增长起到了很重要的作用.但是对于房地产税收的增长情况进行研究,我们不难发现两者是不成正比的.这跟房地产的避税行为有着极大的关系.本文从房地产税收制度的缺失着手,根据会计制度中存在的不足,剖析房地产企业避税行为的本质,并站在会计的角度给出适当的建议.     

谈企业内部会计控制制度设计问题的探讨

内部会计控制制度也是我国企业内部控制主要的组成部分,对于解决会计信息失真,保证企业资产安全、完整,控制经营风险,防止舞弊发生,确保有关法律法规,特别是有关会计方面的法律法规的贯彻执行起到重要作用.     

浅谈对工程统计的认识及其报表设计

2009年颁布实施了新的<中华人民共和国统计法>,使统计工作有法可依,有法必依,可见统计工作的重要程度.施工单位的发展壮大、能力的增强,也可以真实地从统计资料上反应出来.做好统计工作,既有理论的支持,又有实践的论证.