Heavy or semi-heavy tail,that is the question

While there has been considerable research on the analysis of extreme values and outliers by using heavy-tailed distributions, little is known about the semi-heavy-tailed behaviors of data when there are a few suspicious outliers. To address the situation where data are skewed possessing semi-heavy tails, we introduce two new skewed distribution families of the hyperbolic secant with exciting properties. We extend the semi-heavy-tailedness property of data to a linear regression model. In particular, we investigate the asymptotic properties of the ML estimators of the regression parameters when the error term has a semi-heavy-tailed distribution. We conduct simulation studies comparing the ML estimators of the regression parameters under various assumptions for the distribution of the error term. We also provide three real examples to show the priority of the semi-heavy-tailedness of the error term comparing to heavy-tailedness. Online supplementary materials for this article are available. All the new proposed models in this work are implemented by the shs R package, which can be found on the GitHub webpage.     

International Evidence on the Determinants of Organizational Ethical Vulnerability

This paper proposes a model to explain what makes organizations ethically vulnerable. Drawing upon legitimacy, institutional, agency and individual moral reasoning theories we consider three sets of explanatory factors and examine their association with organizational ethical vulnerability. The three sets comprise external institutional context, internal corporate governance mechanisms and organizational ethical infrastructure. We combine these three sets of factors and develop an analytical framework for classifying ethical issues and propose a new model of organizational ethical vulnerability. We test our model on a sample of 253 firms that were involved in ethical misconduct and compare them with a matched sample of the same number of firms from 28 different countries. The results suggest that weak regulatory environment and internal corporate governance, combined with profitability warnings or losses in the preceding year, increase organizational ethical vulnerability. We find counterintuitive evidence suggesting that firms’ involvement in bribery and corruption prevention training programmes is positively associated with the likelihood of ethical vulnerability. By synthesizing insights about individual and corporate behaviour from multiple theories, this study extends existing analytical literature on business ethics. Our findings have implications for firms’ external regulatory settings, corporate governance mechanisms and organizational ethical infrastructure.     

Hamjensgara belongs to family; exclusion and inclusion of male homosexuality in relation to family structure in Iran

This paper looks at current struggles of Iranian gay men to form new sexual identities that are directly tied to family structure and based on values of emotional bond and commitment to a same-sex partner. Based on fieldwork conducted among Iranian gay men in 2012–2014 and through looking at Iranian gay men’s terminologies, Hamjensgara and Gay in particular, I will clarify how Iranian gays, in a way different from that of Western LGBT activists, are trying to portray a positive image of their sexuality in relation to local family standards so they can be integrated into the Iranian family structure, which is the central space of regulating identities in Iran.     

Do Immigrants Catch‐up with the Natives in Terms of Earnings? Evidence from Individual Level Data of Canada

This article analyses differences in dynamic transitions into and out of any of the five hourly wage quintiles and quintile zero (unemployed and non‐employed people) between immigrants and natives for the period 1993‐2004. Using Longitudinal Level data from Survey of Labour and Income Dynamics (SLID) for men aged 25 to 55, we investigate how unobserved heterogeneity factors and initial conditions may affect individuals’ propensity to stay in or leave any of the wage quintiles. We also consider a dynamic multinomial logit model with the random effects approach. Empirical results show that state dependence exists in all hourly wage quintiles. Moreover, education, experience, marital status, immigrant minority status, and age at immigration are significant factors determining hourly wage differentials between immigrants and natives.     

Monitoring two-stage processes with a profile at the second stage

In the multistage processes, quality of a process or a product at each stage is related to the previous stage(s). This property is referred to as a cascade property. Sometimes, quality of a process is characterized by a profile. In this paper, we consider a two-stage process with a normal quality characteristic in the first stage and a simple linear regression profile in the second stage. Then we propose two methods to monitor quality characteristics in both stages. The performance of the proposed two methods is evaluated through a numerical example in terms of average run length criterion.     

Long-term effects of back extensor strengthening exercises on quality of life in women with osteoporosis

The aim of the present study was to evaluate the long-term effect of back extensor strengthening exercises on health-related quality of life (QOL) in women with osteoporosis. In this randomized clinical trial, 183 women with osteoporosis were treated with pharmacotherapy and weight-bearing and balance-training exercises. The case group additionally performed back extensor exercises at home. Patients filled out the Persian version of the Short Form (SF-36) QOL questionnaire at baseline and 6 months post treatment. At the end, all physical and mental parameters of the SF-36 questionnaire improved significantly in the case group, except for one subscale of mental health, compared to the control group. In the control group, only some physical health dimensions (bodily pain, role limitation, physical function, vitality), and mental health status as a mental health subscale improved. In conclusion, considering a major impact of back extensor exercises on improving QOL in women with osteoporosis over the long term, these exercises should be prescribed in routine management of these patients.     

Equity Ownership in Cross‐border Mergers and Acquisitions by British Firms: An Analysis of Real Options and Transaction Cost Factors

The authors investigate the factors influencing the share of equity ownership sought in cross‐border mergers and acquisitions (CBM&As). Drawing on real options theory and transaction cost economics (TCE), they address and hypothesize key factors linked to commitment under exogenous uncertainty and the separation of desired and non‐desired assets’ influence on share of equity sought by acquiring firms in CBM&As. Empirical analysis based on 1872 CBM&As undertaken by British firms in both developed and emerging economies shows that British MNEs are more likely to pursue a partial acquisition in a target foreign firm when those foreign firms are from culturally distant countries. Further, findings support the view that the high cost of separating desired assets from non‐desired assets motivates firms to make a partial acquisition rather than acquire the target completely. This is one of the first studies to use real options theory to address the cost of commitment under exogenous uncertainty, as well as TCE logic to address the separation of desired and non‐desired assets in the target firm while analysing equity ownership sought in CBM&As. Empirically, this paper contributes by examining CBM&As by British firms in both developed and emerging markets.     

Robust multivariate change point analysis based on data depth

Modern methods for detecting changes in the scale or covariance of multivariate distributions rely primarily on testing for the constancy of the covariance matrix. These depend on higher-order moment conditions, and also do not work well when the dimension of the data is large or even moderate relative to the sample size. In this paper, we propose a nonparametric change point test for multivariate data using rankings obtained from data depth measures. As the data depth of an observation measures its centrality relative to the sample, changes in data depth may signify a change of scale of the underlying distribution, and the proposed test is particularly responsive to detecting such changes. We provide a full asymptotic theory for the proposed test statistic under the null hypothesis that the observations are stable, and natural conditions under which the test is consistent. The finite sample properties are investigated by means of a Monte Carlo simulation, and these along with the theoretical results confirm that the test is robust to heavy tails, skewness and high dimensionality. The proposed methods are demonstrated with an application to structural break detection in the rate of change of pollutants linked to acid rain measured in Turkey lake, a lake in central Ontario, Canada. Our test suggests a change in the rate of acid rain in the late 1980s/early 1990s, which coincides with clean air legislation in Canada and the US. The Canadian Journal of Statistics 48: 417–446; 2020 © 2020 Statistical Society of Canada