The natural index and the divisia index on the straight line as well as the divisia index on the exponential line

In earlier papers the Divisia index on the straight line was called natural index. Representing the index problem in the 2n-dimensional quantity-price-space, it is now proposed to call natural index the limit of stepwise products of Laspeyres' , Paasche's or Edgeworth-Marshall s indices, if the steps approximate the straight line between the base point and the observed point. The numerical results of successive finer approximations of the natural index are illustrated by some examples. As expected these approximations converge to the value of the Divisia index on the straight line. The same approximation procedure is applied to the Divisia index on the exponential line.     

Alternative beta estimation for the market model using partially adaptive techniques

The leptokurtosls of many security market return distributions can contaminate ordinary least squares estimates of the β coefficient of the market model. Partially adaptive estimation techniques accommodate the possibility of fat tailed distributions. this methodology limits the influence of extremely large residuals and yields estimates which are both statistically and practically different from ordinary least squares.     

Interval estimation of parameters in an unbalanced mixed two-fold nested classification-the last-stage uniformity case

A procedure for the construction of exact simultaneous confidence intervals on functions of the fixed-effects parameters and on functions of variance components in an unbalanced, mixed, two-fold nested classification is introduced. The type of model considered in this paper enables the construction of such intervals to be based on the corresponding ANOVA table using its mean square ratios.     

Modelling lifetimes by quantile functions using Parzen's score function

The present paper introduces methods of constructing quantile functions as models of lifetimes with monotone and nonmonotone hazard functions. This is accomplished on the basis of the relationships the hazard quantile function has with the score function introduced by Parzen in connection with the tail heaviness of probability distributions. Three models illustrated here contain several existing models as particular cases. The appropriateness of the models in real situations is also demonstrated.     

Stochastic Orderings of Order Statistics of Independent Random Variables with Different Scale Parameters

This is an article on recent results on stochastic comparisons of order statistics of n independent random variables differing in their scale parameters. Most of the results obtained so far are for the Weibull and the Gamma distributions.     

Shrinkage Estimation Under Multivariate Elliptic Models

The estimation of the location vector of a p-variate elliptically contoured distribution (ECD) is considered using independent random samples from two multivariate elliptically contoured populations when it is apriori suspected that the location vectors of the two populations are equal. For the setting where the covariance structure of the populations is the same, we define the maximum likelihood, Stein-type shrinkage and positive-rule shrinkage estimators. The exact expressions for the bias and quadratic risk functions of the estimators are derived. The comparison of the quadratic risk functions reveals the dominance of the Stein-type estimators if p ≥ 3. A graphical illustration of the risk functions under a “typical” member of the elliptically contoured family of distributions is provided to confirm the analytical results.     

Nonparametric repeated significance tests for some analysis of covariance models

For a general class of nonparametric analysis of covariance problems (with stochastic covariates), some repeated significance testing procedures are developed. These procedures rest on the construction of suitable rank order statistics based on the partial sequence of sample sizes and allow for a monitoring of experimentation with the objective of a possible early termination of experimentation. The basic theory is based on the weak convergence of certain stochastic processes relating to the rank order statistics. Various properties of the proposed tests are discussed.     

Bayes estimators of the reliability of the logistic distribution

Bayes estimators of the reliability function of the logistic distribution are obtained using the methods of Lindley (1980) and Tierney & Kadane (1986). Squared-error and log-odds squared-error loss functions are used. A numerical example is presented. Comparisons are made between these two procedures, based on a Monte Carlo simulation study.     

The power functions of the likelihood ratio tests for a simple tree ordering in normal means: unequal weights

Likelihood ratio tests are considered for two testing situations; testing for the homogeneity of k normal means against the alternative restricted by a simple tree ordering trend and testing the null hypothesis that the means satisfy the trend against all alternatives. Exact expressions are given for the power functions for k = 3 and 4 and unequal sample sizes, both for the case of known and unknown population variances, and approximations are discussed for larger k. Also, Bartholomew’s conjectures concerning minimal and maximal powers are investigated for the case of equal and unequal sample sizes. The power formulas are used to compute powers for a numerical example.     

The Implications of Demographic-Specific Inflation Rates for Trends in Real Educational Wage Differentials

We use data from consumer expenditure surveys to investigate the impact on trends in real wage differentials of using group-specific price indexes. We find that inflation rates decrease monoton-ically with the education of the household head throughout the 1970s and early 1980s, and real educational wage differentials, calculated using education-specific price indexes, widened somewhat more than nominal differentials. We also find that differences by education level in fuel and energy consumption, whose relative prices increased during the 1970s, account for the majority of the educational index differences.