The Coordination Role of Stress Tests in Bank Risk‐Taking

We examine whether stress tests distort banks' risk‐taking decisions. We study a model in which a regulator may choose to rescue banks in the event of concurrent bank failures. Our analysis reveals a novel coordination role of stress tests. Disclosure of stress‐test results informs banks of the failure likelihood of other banks, which can reduce welfare by facilitating banks' coordination in risk‐taking. However, conducting stress tests also enables the regulator to more effectively intervene banks, coordinating them preemptively into taking lower risks. We find that, if the regulator has a strong incentive to bail out, stress tests improve welfare, whereas if the regulator's incentive to bail out is weak, stress tests impair welfare.     

Robust Markowitz mean‐variance portfolio selection under ambiguous covariance matrix

This paper studies a robust continuous‐time Markowitz portfolio selection problem where the model uncertainty affects the covariance matrix of multiple risky assets. This problem is formulated into a min–max mean‐variance problem over a set of nondominated probability measures that is solved by a McKean–Vlasov dynamic programming approach, which allows us to characterize the solution in terms of a Bellman–Isaacs equation in the Wasserstein space of probability measures. We provide explicit solutions for the optimal robust portfolio strategies and illustrate our results in the case of uncertain volatilities and ambiguous correlation between two risky assets. We then derive the robust efficient frontier in closed form, and obtain a lower bound for the Sharpe ratio of any robust efficient portfolio strategy. Finally, we compare the performance of Sharpe ratios for a robust investor and for an investor with a misspecified model.     

GB/T2542-2012《砌墙砖试验方法》合理性分析及建议

本文是在GB/T2542-2012《砌墙砖试验方法》实施后,在操作实践中发现配套设备、试验过程和标准的落实中存在一些问题。通过对这些问题进行分析,提出合理化的建议。     

地方高校大型分析测试仪器的管理和使用——以榆林学院为例

本文以榆林学院为例,从地方高校大型分析测试仪器设备发展中呈现出的特点以及存在的问题出发,在提高大型仪器设备的利用率和使用效益等方面进行了分析探讨。     

A characterization of the extended serial correspondence

We study the problem of assigning objects to a group of agents. We focus on probabilistic methods that take agents’ ordinal preferences over the objects. Importantly, we allow for indifferences among objects. Katta and Sethuraman (2006) propose the extended serial correspondence to solve this problem. Our main result is a characterization of the extended serial correspondence in welfare terms by means of stochastic dominance efficiency, stochastic dominance no-envy and “limited invariance,” a requirement we adapt from Heo (2014a). We also prove that an assignment matrix is selected by the extended serial correspondence if and only if it satisfies “non-wastefulness” and “ordinal fairness,” which we adapt from Kesten et al. (2011).     

Corporate Stock and Bond Return Correlations and Dynamic Adjustments of Capital Structure

This paper analyses the effects of dynamic correlations between stock and bond returns issued by the same firm on the speed of adjustment towards target leverage. The results show that the estimated correlations are time varying, show persistence and differ among firms. Analysis of the potential explanatory variables reveals that the correlations decrease with negative expectations about future aggregate risks, but only for firms with a low default probability. In contrast, correlations are positively associated with specific risk measures, especially idiosyncratic stock risk and financial leverage. The positive relationship between the correlations and the leverage ratio suggests that target leverage can be achieved faster when the stock–bond correlation is high. Our results show that this is the case.     

中国商业银行整体效率研究* ——基于具有中间投入和中间产出的综合网络DEA模型

本文基于对银行业务结构和特征的分析，将银行看做具有中间投入和中间产出的串联两阶段网络生产结构。第一阶段为负债业务和中间业务，第二阶段为资产业务。基于这一网络结构，本文首先建立具有中间投入和中间产出的综合网络DEA模型，并证明在此模型下整体网络DEA有效等价于每个子阶段DEA有效，即此模型是打开黑箱的网络DEA模型，并定义网络决策单元的投影。本文以中国16家上市商业银行为样本，测算了2006-2010年各商业银行的整体效率、子阶段效率、关联指数和每家银行的投影。分析结果显示，大型国有商业银行在负债业务和中间业务阶段具有明显的竞争优势，股份制商业银行在资产业务阶段具有效率优势，城市商业银行的两阶段业务关联性最差。本文计算的投影，给出了银行提高整体效率的改进方向。     

STOCK‐BOND CO‐MOVEMENTS AND FLIGHT‐TO‐QUALITY IN G7 COUNTRIES: A TIME‐FREQUENCY ANALYSIS

This paper examines co‐movement between stock returns and changes in 10‐year government bond yields as well as flight‐to‐quality behaviour in G7 countries. We conduct the wavelet squared coherence analysis to explore the dynamics in both time and frequency domain. Our results provide evidence of positive co‐movements, which vary over time and across investment horizon. The higher co‐movement is found to be more concentrated in the lower frequency bands. We further analyse the dynamic nature of the scale‐dependent wavelet correlations and find that the correlations are highly volatile and significantly increase across different time scales during the episodes of equity market turbulence. The increase in correlations reflects flights from stocks to safer bond investments as a result of dramatic changes in investor sentiment and risk aversion at times of market stress.     

利用相位差变化趋势的多源信号关联

针对多源信号关联难度大、关联准确率低的问题，利用同一目标平台上搭载的多个辐射源信号具有一致的动态变化趋势这一特点，提出一种利用相位差特征的多源信号关联方法。已知阵列形式和侦测点位置，通过对侦收到的多个辐射源信号进行处理，获取相位差信息并累积形成相位差变化趋势；对比提取疑似相似段，根据相似性判决策略进行有效关联。该方法能有效避免不同传感器对位置测量的误差影响，相比传统基于位置信息关联的方法，能有效提升关联准确率。仿真和实测数据分析证明了该方法的有效性，在阵列形式和侦测点位置已知的条件下该方法具有重要工程意义。     

大数据对法院司法统计的积极功效及边界

最高人民法院于2016年应用人民法院大数据管理和服务平台以后,全国法院司法统计完全实现计算机自动采集。从发展脉络来看法院司法统计正处于智能化转型阶段,仍然存在一些问题。随着大数据及新技术的引入,司法统计“大数据”得以成为现实,包括了数据采集的全面化、统计分析的综合化、统计平台的社会化,进而提出了大数据助力司法统计精准化的具体路径,包括了提高基础数据的量与质、加强对司法统计数据的深度分析和可视化分析、推进基础设施建设。然而,二者并不具有正相关性。因此,推进司法统计大数据化需要注意有两个限度。