Business ethics,company value and ownership structure

This paper examines the effect of ethical performance on the value of a company and the attractiveness of its stocks for major owners; institutional investors and insiders. Using the Ethisphere^® Institute Ethics Quotient to distinguish between ethical and unethical companies, results show that good ethical performance enhanced company value for a sample of 240 large US companies. Furthermore, strong evidence is found that institutional investors are attracted to ethical companies, but that insiders do not show any investment preferences based on the ethical performance of a company.

     

Selected singular-generalized-hyperbolic distributions with applications to order statistics and reliability

In this paper, the truncated version of the selected multivariate generalized-hyperbolic distributions is introduced. Considering special truncations, the joint distribution of the consecutive order statistics from the multivariate generalized-hyperbolic (GH) distribution is derived. It is shown that this joint distribution can be expressed as mixtures of the truncated selected-GH distributions. All of these truncated distributions are expressed as the selected singular-GH distributions. These results are used to obtain some expressions for the reliability measures such as mean residual life time, mean inactivity time and regression mean residual life for k-out-of-n systems.     

The frequency of sexual abuse and depression in a sample of street children of one of deprived districts of Tehran

The purpose of this study was to determine the frequency of sexual abuse and depression among street children who live in a deprived district of Tehran. The researchers used the K-SADS questionnaire and a clinical interview were used to evaluate depression and sexual abuse in 87 street children in Tehran. Eighteen (20.9%) of the children had been sexually abused. Depressed children were 3.2 times more likely to be sexually abused than non-depressed children. Furthermore, 26 girls (86.7%) and 27 boys (48.2%) suffered from depression. The frequency of depression demonstrated a significant association with the father's or breadwinner's history of imprisonment or unemployment. Interventional programs providing education and support should be implemented for street children.     

Impact of misspecified residual correlation structure on the parameter estimates in a shared spatial frailty model

In practice, survival data are often collected over geographical regions. Shared spatial frailty models have been used to model spatial variation in survival times, which are often implemented using the Bayesian Markov chain Monte Carlo method. However, this method comes at the price of slow mixing rates and heavy computational cost, which may render it impractical for data-intensive application. Alternatively, a frailty model assuming an independent and identically distributed (iid) random effect can be easily and efficiently implemented. Therefore, we used simulations to assess the bias and efficiency loss in the estimated parameters, if residual spatial correlation is present but using an iid random effect. Our simulations indicate that a shared frailty model with an iid random effect can estimate the regression coefficients reasonably well, even with residual spatial correlation present, when the percentage of censoring is not too high and the number of clusters and cluster size are not too low. Therefore, if the primary goal is to assess the covariate effects, one may choose the frailty model with an iid random effect; whereas if the goal is to predict the hazard, additional care needs to be given due to the efficiency loss in the parameter(s) for the baseline hazard.     

Optimization of problems with multivariate multiple functional responses: A case study in air quality

Optimization of multi-response problems is a popular subject in the literature. However, the problem becomes complicated when the responses are functional due to the existence of signal factors. In this article, we have proposed a combined index to optimize multivariate multiple functional responses by considering functional specification limits and a target. The relation among the responses and controllable factors is characterized by polynomial equations to consider the curvature of the response functions. The validity of the proposed method is checked by a simulation example. To show the applicability of the proposed method, a real case about Tehran air quality is analyzed. Latitude and longitude are considered to be signal factors, and different pollutant values are responses of the experiment. Government policies in each time interval are considered as controllable factors. Finally, an optimization algorithm is used to find the best decisions for government policies.     

Poverty comparisons with common relative poverty lines

Relative poverty lines are increasingly being used in poverty comparison studies. Existing methods assume that the distributions being compared are distinct with independent relative poverty lines. However, this practice may be problematic when comparing two subgroups of a population. We follow up on a recent proposal for the usage of common relative poverty lines in such cases, and develop a test for comparing poverty between subgroups of a single population, using inequality restrictions. Monte Carlo experiments are conducted in order to examine the size and power of our proposed test. We illustrate our procedure using some U.S. household income data.     

HIV prevention barriers in transgender women: a qualitative study

Abstract

Sexual contact is still one of the most important routes of HIV transmission. The aim of this study was identify the factors that underlie the higher prevalence of high-risk sexual behaviors in a sample of transgender women in Iran. The qualitative study used face-to-face, semi-structured, in-depth interviews in a sample of 15 transgender women. Our participants used sexual practices as a way to be approved/accepted as a woman. Using sex for this purpose led them to engage in high-risk sexual relationships. It is essential to consider these issues in consulting and education about high-risk behaviors.     

YOUTH,REVOLUTION, AND REPRESSION

We develop a simple model to study the effect of age structure on the interactions between the state and dissidents. Younger populations are more prone to protest. As the population grows younger, states that can discriminately target repression to different groups, but cannot concede discriminately, decrease repression. In contrast, states that can target concession, but not repression, increase repression. We test these results in nonmilitary single‐party regimes and military regimes without political parties. Moreover, we study state response to dissent in East European communist regimes in the late 1980s, showing that state response was more repressive in countries with younger populations. (JEL D74)