Functional analysis of variance for Hilbert-valued multivariate fixed effect models

This paper presents new results on functional analysis of variance for fixed effect models with correlated Hilbert-valued Gaussian error components. The geometry of the reproducing kernel Hilbert space of the error term is considered in the computation of the total sum of squares, the residual sum of squares, and the sum of squares due to the regression. Under suitable linear transformation of the correlated functional data, the distributional characteristics of these statistics, their moment generating and characteristic functions, are derived. Fixed effect linear hypothesis testing is finally formulated in the Hilbert-valued multivariate Gaussian context considered.     

试论动态渐进的情景定位假设

时间三分法和以它为基础的时体理论存在诸多问题。基于此,笔者以语境化理论和时体阶层公式为理论基础,提出了动态渐进的情景定位假设。情景定位假设具有动态性、渐进性,涉及情景、情景体、语法体、时制、时间短语等诸多范畴,且把这些范畴有机地结合到一起,用情景定位假设对现在完成式的定位进行分析并进一步说明此理论的可行性。     

Some pitfalls of tests of separate families of hypotheses: normality vs. lognormality

It is often desirable to test non-nested hypotheses. Cox (1961, 1962) proposed forming a log-likelihood ratio from their maxima and then comparing this value to its expected value under the null hypothesis. Pitfalls exists when we apply Cox's test to the special case of testing normality versus lognormality. Pesaran (1981) and Kotz (1973) pointed out the slow convergence rate of the Cox's test. In this paper, this fact has been reemphasized; moreover, we propose an alternative likelihood ratio test which remedies problems arising from negative estimates of the asymptotic variance of Cox's test statistic and is uniformly more powerful than most commonly used tests.     

Estimation in the simple linear regression model when there is heteroscedasticity of unknown form

A well-known problem is that ordinary least squares estimation of the parameters in the usual linear model can be highly ineficient when the error term has a heavy-tailed distribution. Inefficiency is also associated with situations where the error term is heteroscedastic, and standard confidence intervals can have probability coverage substantially different from the nominal level. This paper compares the small-sample efficiency of six methods that address this problem, three of which model the variance heterogeneity nonparametrically. Three methods were found to be relatively ineffective, but the other three perform relatively well. One of the six (M-regression with a Huber φ function and Schweppe weights) was found to have the highest efficiency for most of the situations considered in the simulations, but there might be situations where one of two other methods gives better results. One of these is a new method that uses a running interval smoother to estimate the optimal weights in weighted least squares, and the other is a method recently proposed by Cohen, Dalal, and Tukey. Computing a confidence interval for the slope using a bootstrap technique is also considered.     

A NONPARAMETRIC TEST FOR THE EQUALITY OF DEPENDENT CORRELATION COEFFICIENTS UNDER NORMALITY

ABSTRACT

A nonparametric testing method for the equality of two correlation coefficients in trivariate normal distribution, namely, one of the variables are common, is discussed. Using a permutation test, we obtain asymptotically exact solutions. The performance of this test is compared with the likelihood ratio test and a method of using the limiting distribution of correlation coefficients.     

金融资产管理公司的市场结构与绩效

运用现代产业组织的“有效结构假说”等相关理论,对形成金融资产管理公司不良资产的结构性因素包括市场份额、市场集中度和市场壁垒等项关联指标进行分析,同时对财政部经营目标的完成情况进行对比分析。分析认为,垄断型的市场结构是制约资产管理公司提高经营绩效的重要因素。分析结果表明：要不断提升资产管理公司的经营绩效必须改变其市场结构,加强公司的约束机制与激励机制建设。     

A new futility test approach in clinical interim data monitoring

Sequential monitoring of efficacy and safety data has become a vital component of modern clinical trials. It affords companies the opportunity to stop studies early in cases when it appears as if the primary objective will not be achieved or when there is clear evidence that the primary objective has already been met. This paper introduces a new concept of the backward conditional hypothesis test (BCHT) to evaluate clinical trial success. Unlike the regular conditional power approach that relies on the probability that the final study result will be statistically significant based on the current interim look, the BCHT was constructed based on the hypothesis test framework. The framework comprises a significant test level as opposed to the arbitrary fixed futility index utilized in the conditional power method. Additionally, the BCHT has proven to be a uniformly most powerful test. Noteworthy features of the BCHT method compared with the conditional power method will be presented. Copyright © 2012 John Wiley & Sons, Ltd.     

Social Contact,Social Distancing,and Attitudes Toward LGT Individuals: A Cross-Cultural Study of College Students in the United States,Italy, and Spain

ABSTRACT

More than any other time in modern history, today people are significantly more likely to know (or be) lesbian, gay, and transgender (LGT) people; however, prejudices directed toward these groups remain. In the current study, we explore how social contact and social distancing/desired social contact are related to LGT prejudices using Worthen’s (2012) Attitudes Toward LGT People Scales and data from four heterosexual college student samples in Oklahoma, Texas, Italy, and Spain (N = 1,217). In doing so, we provide the first-ever study to explore Allport’s (1954) contact hypothesis as it relates to transgender prejudices in Italy and Spain and the first study to examine desired social contact/social distancing and transgender prejudice in the U.S., Italy, and Spain. Our findings demonstrate that measures of desired social contact are strongly related to cross-cultural LGT attitudes, while simple measures of contact (i.e., knowing an LGT person) are significantly less robust.     

Bayes factor in testing precise hypotheses

Substitution of a mixed prior distribution by a continuous one for the point null hypothesis testing problem is discussed. Conditions are established in order to approximate the Bayes factors for the two problems. Besides, trough this approximation an assignation of priorprobabilities is suggested.     

Comment: Uses of Administrative Records: A Social Security Point of View

Recent evidence indicates that using multiple forward rates sharply predicts future excess returns on U.S. Treasury Bonds, with the R²'s being around 30%. The projection coefficients in these regressions exhibit a distinct pattern that relates to the maturity of the forward rate. These dimensions of the data, in conjunction with the transition dynamics of bond yields, offer a serious challenge to term structure models. In this article we show that a regime-shifting term structure model can empirically account for these challenging data features. Alternative models, such as affine specification, fail to account for these important features. We find that regimes in the model are intimately related to bond risk premia and real business cycles.