规模组合、因子定价与均值方差张成 --来自中国A股的证据

本文从均值方差张成的角度探讨了多因子定价模型在中国的适用性,并对规模组合能否作为定价因子这一问题进行了实证考察。对沪深两市A股的10个规模组合的均值方差张成检验表明,大、中、小3个规模组合在短期内可以张成所有的规模组合的均值方差边界,这意味着这3个规模组合可以作为定价因子,解释其他风险资产收益率的变动。     

Firm size and productivity in Spain: a stochastic frontier analysis

This paper analyses the performance of the small and medium-sized manufacturing firms during the period 1995–2001, focusing on the degree of technical inefficiency and its determinants. We use a micro panel data set to simultaneously estimate a stochastic frontier production function and the inefficiency determinants using an unbalanced panel of manufacturing firms. Our empirical results suggest that small and medium-sized firms tend to be less inefficient than the large firms are. Also, we centre our analysis in the effect on efficiency of some organisational factors related to the managerial ability to use and adjust capital and labour properly.

Bayesian Premium Rating with Latent Structure

We propose a fully Bayesian approach to non-life risk premium rating, based on hierarchical models with latent variables for both claim frequency and claim size. Inference is based on the joint posterior distribution and is performed by Markov Chain Monte Carlo. Rather than plug-in point estimates of all unknown parameters, we take into account all sources of uncertainty simultaneously when the model is used to predict claims and estimate risk premiums. Several models are fitted to both a simulated dataset and a small portfolio regarding theft from cars. We show that interaction among latent variables can improve predictions significantly. We also investigate when interaction is not necessary. We compare our results with those obtained under a standard generalized linear model and show through numerical simulation that geographically located and spatially interacting latent variables can successfully compensate for missing covariates. However, when applied to the real portfolio data, the proposed models are not better than standard models due to the lack of spatial structure in the data.     

平滑转移误差修正模型的转移函数选取问题研究

针对非线性平滑转移误差修正模型转移函数选取中存在的统计量极限分布非标准、检验统计量功效较低的问题,本文在推导非线性平滑转移协整检验统计量极限分布的基础上构造了如下转移函数选取步骤。首先,计算F_NST统计量,进行非线性平滑转移协整检验;其次,计算t_EST和t_LST统计量及相依概率P_est和P_lst;最后,比较P_est和P_lst大小并与临界值相比,得出结论。蒙特卡洛仿真模拟结果显示,转移函数选取中各统计量具有良好的功效和势,且转移函数选取中各统计量的功效明显优于其他统计量的功效。实证分析表明我国利率期限结构具有明显的非线性对称调整效应,非线性平滑转移误差修正模型中转移函数应该选取指数函数。     

Australian evidence on the implementation of the size and value premia

This study investigates whether passive investment managers can exploit the size and value premia without incurring prohibitive transaction costs or being exposed to substantial tracking error risk. Returns on the value premium are shown to be pervasive across size groups, while the size premium is nonlinear and driven by microcaps. The value premium cannot be explained by the capital asset pricing model; however, returns on value portfolios do covary across monetary regimes. The substantial turnover required to achieve annual rebalancing and the relative illiquidity of Australian small‐cap firms means that investing in a portfolio of large‐cap value firms appears to be the best way for passive fund managers to exploit the Fama and French (1993) premia.     

Corruption and industrial dualism in less developed countries

This paper provides an explanation for the observation that developing countries tend to have a higher degree of dualism in the size distribution of firms and a relatively smaller proportion of large firms than do developed countries. This paper builds a model where large 'formal' firms attract rent seeking activities from the government while small firms do not. In the model, there exists a 'competitive fringe' of small firms and a formal market consisting of Cournot competitors. The number of formal firms is made endogenous and is a function of the degree to which the government can extract rents. This ability to extract rents is itself posited as a function of the degree of corruption in a country's government. Thus, it is the high degree of corruption in developing country governments that contributes to the dual nature of their industrial structure. The model predicts that the higher the degree of corruption, the fewer (and larger) are the formal firms, the lower is social welfare and the greater is dead-weight loss, and the higher are government rents. An examination of the size distribution of 16 countries and their degree of corruption shows that the degree of corruption is a good predictor of the percentage of large firms in an economy.     

大中小微企业规模划型统计标准的实证研究

研究目标:引入机器学习方法讨论大中小微企业规模划型标准问题。研究方法:基于国家统计局公开的第四次经济普查企业数据,采用Adasampling方法,结合基本描述统计方法判断企业规模划型问题。研究发现:多数行业规模划型采用单一指标可达到较好划分效果,缓解小微企业划分过于宽松的痼疾,简化分类识别难度;现行小微企业分类阈值较为合理,但中小企业间和大中企业间分类阈值有明显偏差;可细化当前的企业规模划型标准,基于行业大类特征进行企业规模划型;分类阈值可建立机器学习与经济普查相结合的定期动态调整机制。研究创新:引入Adasampling方法讨论企业规模划型指标选取和划分阈值标准。研究价值:从理论上论证我国企业规模划型标准的科学性和优化方向。     

Empirical size and power of some diagnostic tests applied to a distributed lag model

We produce Monte Carlo evidence on the size and power of the RESET, a heteroscedasticity test, and a test for autocorrelation applied to realistic distributed-lag models. We find that the autocorrelation test has the correct size and high power to detect not only autocorrelation (given a correct model), but also the erroneous omission of several lags of an explanatory variable, whereas the RESET and heteroscedasticity tests are oversized in the presence of positive disturbance autocorrelation, especially when the regressors are also positively autocorrelated, and have no power to detect such misspecification errors. In large samples, size distortion may be avoided by using autocorrelation-robust methods.

基于改进阿格沃尔模型及需求函数法的我国外汇储备规模实证研究

本文根据我国经济具体发展情况,对阿格沃尔模型进行了改进,建立了适合预测我国外汇储备规模趋势的需求函数模型。利用改进的阿格沃尔模型测算了我国1982-2008年各年的外汇储备适度规模,与实际外汇储备规模进行了比较分析,并利用需求函数模型基于1982-2008年的年度数据,预测了我国外汇储备规模的发展趋势。研究结果表明:1982-1995年我国外汇储备不足,1996-2001年外汇储备规模适度,2002-2008年外汇储备规模过度;1982-2008年我国外汇储备规模持续上升,未来仍将继续保持增长态势。最后结合我国经济发展现状,对我国外汇储备管理提出有针对性的建议。     

转换成本、网络规模与信用卡产业竞争策略比较

近年来,我国信用卡产业呈现出市场集中度逐年下降的趋势。信用卡市场的竞争融合了网络效应、兼容性及转换成本等因素,而在兼容性一定的环境下,不同银行的竞争策略往往不同。本文通过防降价均衡模型估计出2010—2012年我国九家上市银行的信用卡转换成本,并对网络规模扩张、转换成本定位以及竞争成效等进行分组比较。结果表明,股份制商业银行利用较低的转换成本吸引新客户,实现了更高的业务规模增长率;四大国有商业银行则利用高转换成本锁定其已有客户,并以高速扩张网络规模来竞争新客户,使其同股份制商业银行的业务规模增长率差异逐年下降。这说明网络产业中不同市场地位的厂商可将转换成本定位与网络规模扩张作为差异化策略,以此实现竞争优势。