ON MODELING ADVERTISING PULSING DECISIONS

Based on empirical findings in the literature, sales response to advertising pulsing policy (APP) is modeled mathematically. The implications for APP are discussed. This policy is compared with an alternative policy of uniform expenditures (UAP), a commonly used strategy. The results of the research indicate that substantial savings in advertising budget or an increase in sales revenues may be achieved for a firm using APP.     

Nonlinear models of disability and age applied to census data

It is usually considered that the proportion of handicapped people grows with age. Namely, the older the man/woman, the more the level of disability he/she suffers. However, empirical evidence shows that this assessment is not always true, or at least, it is not true in the Spanish population. The study tries to assess the impact of age on disability in Spain. Each gender has been treated separately because it can be shown that men and women have their own pattern of behaviour. Three different methods of estimation have been used to check the link between those variables. The results seem to support the idea that the relationship among age and the intensity of disability is not always direct. One of the concluding remarks in this analysis is that the method of estimation has a great incidence in the final results, especially in central ages between 20 and 80 years old.     

Bayesian unit-root tests for Stochastic Volatility models

In this article, we consider Bayesian inference procedures to test for a unit root in Stochastic Volatility (SV) models. Unit-root tests for the persistence parameter of the SV models, based on the Bayes Factor (BF), have been recently introduced in the literature. In contrast, we propose a flexible class of priors that is non-informative over the entire support of the persistence parameter (including the non-stationarity region). In addition, we show that our model fitting procedure is computationally efficient (using the software WinBUGS). Finally, we show that our proposed test procedures have good frequentist properties in terms of achieving high statistical power, while maintaining low total error rates. We illustrate the above features of our method by extensive simulation studies, followed by an application to a real data set on exchange rates.     

Smooth goodness of fit tests for the weibull distribution with singly censored data

The smooth goodness of fit tests are generalized to singly censored data and applied to the problem of testing Weibull (or extreme value) fit. Smooth tests, Pearson-type tests, and the spacings tests proposed by Mann, Schemer, and Fertig (1973) are compared on the basis of local asymptotic relative efficiency with respect to the asymptotic best test against generalized gamma alternatives, The smooth test of order one Is found to be most efficient for the generalized gamma alternatives.     

A frailty model for (interval) censored family survival data,applied to the age at onset of non-physical problems

Family survival data can be used to estimate the degree of genetic and environmental contributions to the age at onset of a disease or of a specific event in life. The data can be modeled with a correlated frailty model in which the frailty variable accounts for the degree of kinship within the family. The heritability (degree of heredity) of the age at a specific event in life (or the onset of a disease) is usually defined as the proportion of variance of the survival age that is associated with genetic effects. If the survival age is (interval) censored, heritability as usually defined cannot be estimated. Instead, it is defined as the proportion of variance of the frailty associated with genetic effects. In this paper we describe a correlated frailty model to estimate the heritability and the degree of environmental effects on the age at which individuals contact a social worker for the first time and to test whether there is a difference between the survival functions of this age for twins and non-twins.     

Methods for calculating stationary distribution in linear models of time series

The article deals with methods for computing the stationary marginal distribution in linear models of time series. Two approaches are described. First, an algorithm based on approximation of solution of the corresponding integral equation is briefly reviewed. Then, we study the limit behaviour of the partial sums c ₁ η₁+c ₂ η₂+···+c _n η _n where η _i are i.i.d. random variables and c _i real constants. We generalize procedure of Haiman (1998) [Haiman, G., 1998, Upper and lower bounds for the tail of the invariant distribution of some AR(1) processes. Asymptotic Methods in Probability and Statistics, 45, 723–730.] to an arbitrary causal linear process and relax the assumptions of his result significantly. This is achieved by investigating the properties of convolution of densities.     

On computer generation of gamma random variables by rejection and composition procedures 2

The paper presents various algorithms for generating gamma random variables, by combining rejection and composition procedures. Two efficient algorithms are given for the case when the parameter of the gamma distribution is 0<v<l. For the case vl, several algorithms are given but they (except one), work reliably only for small values of v. Results of some computer tests together with FORTRAN subroutines are also presented.     

A Social Problems Approach to Gerontology in Social Work Education

This paper proposes a social problems emphasis to gerontology in social work education which acknowledges the fact that the elderly are handicapped and discriminated against by social values, attitudes, and practices. The traditional integrative approach has been ineffective in educating and sensitizing students to problems and needs of the aged. The social problems emphasis is discussed as related to future manpower needs, enlightened social workers as citizens, and advocacy for the elderly. A proposal for schools is presented, with implications for practice, fieldwork settings, research, and classroom instruction.     

Who Benefits from Religion?

Many studies have documented the benefits of religious involvement. Indeed, highly religious people tend to be healthier, live longer, and have higher levels of subjective well-being. While religious involvement offers clear benefits to many, in this paper we explore whether it may also be detrimental to some. Specifically, we examine in detail the relation between religious involvement and subjective well-being. We first replicate prior findings showing a positive relation between religiosity and subjective well-being. However, our results also suggest that this relation may be more complex than previously thought. While fervent believers benefit from their involvement, those with weaker beliefs are actually less happy than those who do not ascribe to any religion—atheists and agnostics. These results may help explain why—in spite of the well-documented benefits of religion—an increasing number of people are abandoning their faith. As commitment wanes, religious involvement may become detrimental to well-being, and individuals may be better off seeking new affiliations.     

Immigrant fertility patterns and differentials in Australia, 1971–1976

In this paper the fertility patterns and differentials among various immigrant groups in Australia are examined. Official vital statistics for the period 1971–76 are used.

Fertility ratios standardized by age and marital status suggest that the overall fertility of foreign-born women was higher in both 1971 and 1976; however, some evidence -of convergence towards an ‘Australian’ norm was found.

Four distinct patterns of fertility were noted. In two of them, Arab and South European, marital fertility was substantially higher but non-marital fertility quite low. The North-West European pattern was closest to that of the native-born; however, in the East European pattern fertility was lowest. Component analysis showed that most of the differences between the total fertility rate of Australians and those of the other groups reflect the significantly higher marital fertility rates and proportions married among the foreign-born groups.