A note on the relationship between conditional and unconditional independence and its extensions for Markov kernels

Two known results on the relationship between conditional and unconditional independence are obtained as a consequence of the main result of this paper, a theorem that uses independence of Markov kernels to obtain a minimal condition, which, added to conditional independence, implies independence. Some examples, counterexamples, and representation results are provided to clarify the concepts introduced and the propositions of the statement of the main theorem. Moreover, conditional independence and the mentioned results are extended to the framework of Markov kernels.     

A note on the uniform asymptotic normality of location M-estimates

In the robustness framework, the parametric model underlying the data is usually embedded in a neighborhood of other plausible distributions. Accordingly, the asymptotic properties of robust estimates should be uniform over the whole set of possible models. In this paper, we study location M-estimates calculated with a previous generalized S-scale and show that, under some regularity conditions, they are uniformly asymptotically normal over contamination neighborhoods of known size. There is a trade off between the size of the neighborhood and the breakdown point of the GS-scale, but it is possible to adjust the estimates so that they have 50% breakdown point whereas the uniform asymptotic normality is ensured over neighborhoods that contain up to 25% of contamination. Alternatively, both the breakdown point and the size of the neighborhood could be chosen to be 38%. These results represent an improvement over those obtained recently by Salibian-Barrera and Zamar (2004) J.R. Berrendero was Spanish supported by Grant BFM2001-0169 and Grand 06/0050/2003 (Comunidad De Madrid) R. H. Zamar was partially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC).     

The Brand Choice Model of Wine Consumers: A Multinomial Logit Model

The objective of this study is to determine factors influencing brand preferences of wine consumers in the Marmara region where viniculture and wine production is so important in Turkey. First, the consumers’ preferences survey has been conducted with 1022 persons in the region randomly selected and evaluated. Then, the informative factors influencing brand preferences collected in these surveys have been determined by the multinomial logit model. A lot of independent variables have been used in the multinomial logit model, but, because some independent variables were not found as significant according to Likelihood Ratio test, these variables are not included in the multinomial logit analysis. Six important factors influencing wine brand preferences have been determined. These factors are brand change causes of consumers, occupation of consumers, marital status of consumers, birthplace of consumers, income of consumers and gender of consumers. In addition, whether the wine brand preferences are independent, has been tested with Testing Independence of Irrelevant Alternatives of Hausman. According to this test, it has been found that the wine brand preferences are independent.     

A sequential procedure to test three values of a binomial parameter

Sequential tests to decide among three binomial probabilities are needed in many situations, such as acceptance sampling used to determine the proportion of defective items and presence and absence sampling to decide whether pest species are causing economic damage to a crop such as corn. Approximate error probabilities associated with Armitage's (1950, JRSS B) method of simultaneously conducting three sequential probability ratio tests (SPRTs) are derived for the binomial distribution. These approximations provide a basis for adjusting the error rates used to establish the individual SPRTs so that the desired overall error rates are attained. Monte Carlo simulation is used to evaluate the revised procedure. Received: September 1998     

A note on studentizing a test for heteroscedasticity

Breusch and Pagan (1979) have recently proposed a convenient test for heteroscedasticity in general linear models. This note derives the asymptotic distribution of their test under sequences of contiguous alternatives to the null hypothesis of homoscedasticity. The test is shown to possess asymptotically incorrect size (nominal significance level) except in the case of strictly Gaussian disturbances. A slight modification of the test is proposed which corrects this defect.     

Bargaining with independence of higher or irrelevant claims

This paper studies independence of higher claims and independence of irrelevant claims on the domain of bargaining problems with claims. Independence of higher claims requires that the payoff of an agent does not depend on the higher claim of another agent. Independence of irrelevant claims states that the payoffs should not change when the claims decrease but remain higher than the payoffs. Interestingly, in conjunction with standard axioms from bargaining theory, these properties characterize a new constrained Nash solution, a constrained Kalai–Smorodinsky solution, and a constrained Kalai solution.     

The effect of board independence on dividend payouts: A quasi-natural experiment

Motivated by agency theory, we investigate the effect of board independence on dividend policy. We exploit as a quasi-natural experiment the passage of the Sarbanes-Oxley Act and the associated exchange listing requirement, mandating firms to have a majority of independent directors. Our difference-in-difference estimates show that firms forced to raise board independence are significantly more likely to pay dividends than firms not required to change board independence. Our results are consistent with the notion that stronger board independence forces managers to disgorge more cash to shareholders, thereby reducing what is left for possible expropriation by opportunistic managers. Based on an exogenous regulatory shock, our results are more likely to show a casual effect, rather than merely an association.     

The influence of ownership structure and board independence on the cost of debt in BRIC countries

Agency theory predicts that the default premium on debt is determined by the intensity of agency conflicts since they affect the risk of debtholders. This effect is especially important in emerging countries with high ownership concentration and low protection of minority owners. This paper presents an empirical analysis of the influence of ownership structure and board independence on the cost of debt in BRIC countries over the period 2007–2020. The main finding of the study is the presence of significant country-specific effects of ownership structure on the cost of debt measured with the G-spread on corporate bonds, as well as the absence of effects of board independence. According to our results, concentrated ownership and state ownership increase the cost of debt in Brazil and Russia, while decreasing it in China. We reveal that institutional investors help mitigate the risks of debtholders in China, while insider ownership decreases the default risk in Brazil.     

A non-parametric test for independence based on symbolic dynamics

In the present paper we propose a powerful, yet simple, non-parametric test for independence based on symbolic dynamic analysis. The absence of dependences in the unknown underlying data generating process is studied via symbolic dynamics. This is possible due to the ordering property of real numbers on an interval. Interestingly, the test is closely related to entropy concepts. Apart from being correctly sized, the new test is powerful for realistic finite data sets, and it is easy to use as one does not need to select any free parameter, which sharply contrasts with other tests of independence. In addition, the test is robust in the presence of noise which is one of the most typical cases when dealing with economic time series.     

The effect of judicial independence on entrepreneurship in the US states

The relationship between institutional quality, entrepreneurship, and economic growth has been well documented within the literature. However, much less work has been done regarding judicial independence and how this affects, specifically, entrepreneurial activity. Therefore, this paper attempts to fill that gap by exploiting the differences in judicial independence that exist between the US states and empirically evaluating how this affects entrepreneurship. Overall, the results suggest that the method of selecting and retaining justices of both courts of last resort and intermediate appellate courts has a significant and direct effect on entrepreneurial activity, though the latter result is somewhat less robust. The presence of judicial nominating and retention commissions also has a significant and direct effect. Further, although somewhat weaker, the method of selecting the chief justice of a state court of last resort would also appear to have an impact on entrepreneurship. These results are robust to a number of specifications.     

A note on connectedness of block designs

Summary We give a simple proof for the well known result that a block design (for an additive, fixed effects block model withv treatments inb blocks) is connected iff its ℰ-matrix has rankv-1.     

Comment on: A non-parametric spatial independence test using symbolic entropy

In a recent paper López et al. (2010) introduce a new test for spatial independence. The test is a generalization of tests developed in Matilla-García (2007) and Matilla-García and Marín (2008). The results derived need some clarification.     

A note on van Damme's mechanism

We consider (two-person) bargaining games and we assume that the agents want to apply two possibly different bargaining solutions. A mechanism is a function which assigns an allocation to every bargaining game and every pair of bargaining solutions. Examining van Damme's mechanism (1986) from a cooperative point of view we see that it fails to satisfy Pareto-optimality. By modifying it we propose a new mechanism yielding the same conclusions as the original while enjoying some additional desirable properties. Received: 8 August 1998 / Accepted: 15 October 1998     

A note on the equivalence of specification tests in the two-factor multivariate variance components model

This note offers a generalization of Hausman and Taylor's equivalence of specification tests in the single-equation variance (error) components model to the two-factor multivariate variance components case. The relationship between the specification tests and the hypothesis test in the model proposed by Mundlak is also discussed.     

A specification test for the propensity score using its distribution conditional on participation

Propensity score matching has become a popular method for the estimation of average treatment effects. In empirical applications, researchers almost always impose a parametric model for the propensity score. This practice raises the possibility that the model for the propensity score is misspecified and therefore the propensity score matching estimator of the average treatment effect may be inconsistent. We show that the common practice of calculating estimates of the densities of the propensity score conditional on the participation decision provides a means for examining whether the propensity score is misspecified. In particular, we derive a restriction between the density of the propensity score among participants and the density among nonparticipants. We show that this restriction between the two conditional densities is equivalent to a particular orthogonality restriction and derive a formal test based upon it. The resulting test is shown via a simulation study to have dramatically greater power than competing tests for many alternatives. The principal disadvantage of this approach is loss of power against some alternatives.     

A note on the determination of A-optimal type block designs under fixed and mixed effects models

In this paper, we consider the problem of estimating a selected set of contrasts between v treatments using a block design consisting of b blocks of size k. Traditionally, the construction of A-optimal block designs for such situations has been carried out assuming a fixed effects model. In this paper, we show that A-optimal designs constructed under a fixed effects model are robust in the sense that these designs have maximal minimal efficiency when considered among all available designs and under all possible mixed effects models. AMS 1991 subject classifications: Primary 62K05; Secondary 62K10     

A New Index of Independence of 12 European National Central Banks

Abstract

Many countries have recently strengthened the autonomy of their central banks in the effort to protect central bankers from government influences. This article reviews and extends the relevant literature to propose a new ranking of central bank independence in contrast to those originated by Bade and Parking, and Cukierman. The analysis shows a bivariate relationship between independence and inflation rates in 12 European Union countries in the EMS era. However, neither inflation nor its standard deviation had any statistical significance effect on real GDP growth. The procedure reveals that findings are, sometimes, index-specific.     

A note on the maximum deviation of the scale-contaminated normal to the best normal distribution

In this paper we consider the case of the scale-contaminated normal (mixture of two normals with equal mean components but different component variances: (1−p)N(μ,σ²)+pN(μ,τ²) with σ and τ being non-negative and 0≤p≤1). Here is the scale error and p denotes the amount with which this error occurs. It's maximum deviation to the best normal distribution is studied and shown to be montone increasing with increasing scale error. A closed-form expression is derived for the proportion which maximizes the maximum deviation of the mixture of normals to the best normal distribution. Implications to power studies of tests for normality are pointed out. Received May 2001     

A note on Musgrave asymmetrical trend-cycle filters

In this paper, we derive the implicit forecasts in the asymmetrical trend-cycle averages used in the X-11 seasonal adjustment method. We give an algorithm to calculate them, and we study their statistical properties. We express the forecasts as Stein estimators. We derive expressions for their bias, variance, covariances and prediction mean squared errors. We show that the prediction mean squared errors of the implied predictors are always smaller or equal to those obtained using the least squares predictors. Finally, we derive the prior distributions under which the implied predictors are Bayes estimators.     

A note on generalized aberration in factorial designs

In this paper we extend the wordlength pattern and minimum aberration for non-regular factorials. The new concepts, the generalized wordlength pattern and minimum generalized aberration, are proposed. Some connections between the generalized wordlength pattern and uniformity are given. Some applications of the new concepts in the Blackett and Burman's designs are discussed. Received: September 2000