On the Application of Conditional Independence to Ordinal Data

A special log linear parameterization is described for contingency tables which exploits prior knowledge that an ordinal scale of the variables is involved. It is helpful, in particular, in guiding the possible merging of adjacent levels of variables and may simplify interpretation if higher-order interactions are present. Several sets of data are discussed to illustrate the types of interpretation that can be achieved. The simple structure of the maximum likelihood estimates is derived by use of Lagrange multipliers.     

Bootstrap refinements for QML estimators of the GARCH(1,1) parameters

This paper reconsiders a block bootstrap procedure for Quasi Maximum Likelihood estimation of GARCH models, based on the resampling of the likelihood function, as proposed by Gonçalves and White [2004. Maximum likelihood and the bootstrap for nonlinear dynamic models. Journal of Econometrics 119, 199–219]. First, we provide necessary conditions and sufficient conditions, in terms of moments of the innovation process, for the existence of the Edgeworth expansion of the GARCH(1,1) estimator, up to the k$k$-th term. Second, we provide sufficient conditions for higher order refinements for equally tailed and symmetric test statistics. In particular, the bootstrap estimator based on resampling the likelihood has the same higher order improvements in terms of error in the rejection probabilities as those in Andrews [2002. Higher-order improvements of a computationally attractive k$k$-step bootstrap for extremum estimators. Econometrica 70, 119–162].     

利率模型的发展及计量方法的应用

利率模型的发展和完善与计量经济学方法的发展密不可分。综述利率模型的发展和计量方法之应用对利率模型的推动作用,重点介绍单因子扩散利率模型及其极大似然估计、广义矩估计和非参数方法在利率模型中的应用。     

Covariance dependent kernels,a Q-affine GARCH for multi-asset option pricing

This paper introduces a class of multivariate GARCH models that extends the existing literature by explicitly modeling correlation dependent pricing kernels. A large subclass admits closed-form recursive solutions for the moment generating function under the risk-neutral measure, which permits efficient pricing of multi-asset options. We perform a full calibration to three bivariate series of index returns and their corresponding volatility indexes in a joint maximum likelihood estimation. The results empirically confirm the presence of correlation dependance in addition to the well known variance dependance in the pricing kernel. The model improves both the overall likelihood and the VIX-implied likelihoods, with a better fitting of marginal distributions, e.g., 15% less error on one-asset option prices. The new degree of freedom is also shown to significantly impact the shape of marginal and joint pricing kernels, and leads to up to 53% differences for out-of-the-money two-asset correlation option prices.     

MAXIMUM ENTROPY REVISITED

Maximum entropy or minumum information distributions have their flexibilities severely curtailed if R or R₊ is the domain and α is imposed as a Lebesgue measure. Tremendous flexibility is gained by removing these restrictions.     

Maximum entropy autoregressive conditional heteroskedasticity model

In many applications, it has been found that the autoregressive conditional heteroskedasticity (ARCH) model under the conditional normal or Student’s t distributions are not general enough to account for the excess kurtosis in the data. Moreover, asymmetry in the financial data is rarely modeled in a systematic way. In this paper, we suggest a general density function based on the maximum entropy (ME) approach that takes account of asymmetry, excess kurtosis and also of high peakedness. The ME principle is based on the efficient use of available information, and as is well known, many of the standard family of distributions can be derived from the ME approach. We demonstrate how we can extract information functional from the data in the form of moment functions. We also propose a test procedure for selecting appropriate moment functions. Our procedure is illustrated with an application to the NYSE stock returns. The empirical results reveal that the ME approach with a fewer moment functions leads to a model that captures the stylized facts quite effectively.     

Some Improved Tests for Multivariate One-Sided Hypotheses

Multivariate one-sided hypothesis-testing problems are very common in clinical trials with multiple endpoints. The likelihood ratio test (LRT) and union-intersection test (UIT) are widely used for testing such problems. It is argued that, for many important multivariate one-sided testing problems, the LRT and UIT fail to adapt to the presence of subregions of varying dimensionalities on the boundary of the null parameter space and thus give undesirable results. Several improved tests are proposed that do adapt to the varying dimensionalities and hence reflect the evidence provided by the data more accurately than the LRT and UIT. Moreover, the proposed tests are often less biased and more powerful than the LRT and UIT.     

The optimal bid/ask spread in a Specialist System

In this work we propose a simple market model where some features of the Specialist System are analyzed. In particular, the specialist's obligation to display bid/ask quotes on the book within the bounds imposed by the Exchange is considered. The proposed model allows to analyze the effects of the specialist's interventions on the short term dynamics of bid/ask prices and address a relevant market design issue, that is determination and analysis of the optimal endogenous upper bound that - according to economic conditions - should be imposed by Stock Exchange on the quoted bid/ask spread. The institutional details are summarized in a few structural parameters and the focus is on the aggregate effects of excess demand/supply.     

盈余管理:动因及后果——兼与利润操纵的比较

盈余管理的动因有终极动因和中介动因,其根本目的是实现自身效用或公司市场价值最大化,其经济后果有弊也有利.而利润操纵完全是为了谋取私利,且不惜牺牲其他相关人的利益,故它是百害而无一利的.为促进资本市场的理性发展,应当完善相关的法律法规以对二者进行规避.     

我国货币供应时序结构的奇异谱分析

时间序列的结构分析是深入研究原始序列的重要前提。应用奇异谱分析并以极大熵谱估计为辅助,对我国广义货币供应量M2进行时间序列结构分析,结果显示:改革开放以来,我国广义货币供应量M2除了趋势项外,还具有周期分别约为10年、4～5年和3年,方差解释能力依次为23.22%、7.48%和3.44%的主周期波动成分;所有的周期波动成分的振幅均随时间而增大;长期趋势在改革开放前期增长速度较慢,而在中后期增长速度较快。