Analysis of over-dispersed count data with extra zeros using the Poisson log-skew-normal distribution

ABSTRACT

Mixed Poisson distributions are widely used in various applications of count data mainly when extra variation is present. This paper introduces an extension in terms of a mixed strategy to jointly deal with extra-Poisson variation and zero-inflated counts. In particular, we propose the Poisson log-skew-normal distribution which utilizes the log-skew-normal as a mixing prior and present its main properties. This is directly done through additional hierarchy level to the lognormal prior and includes the Poisson lognormal distribution as its special case. Two numerical methods are developed for the evaluation of associated likelihoods based on the Gauss–Hermite quadrature and the Lambert's W function. By conducting simulation studies, we show that the proposed distribution performs better than several commonly used distributions that allow for over-dispersion or zero inflation. The usefulness of the proposed distribution in empirical work is highlighted by the analysis of a real data set taken from health economics contexts.     

Virtual Governance Networking Policies: A Comparative Analysis

Networks have become an increasingly important mode of public governance. ICT mechanisms, especially virtual systems will potentially establish this idea. This paper is based on a comparative analysis of three cases which are chosen to be particularly illustrative of the three virtual governance networking policies. In light of case study results, we have demonstrated that it is possible to devise a theoretically acceptable prospect of world countries concerning virtual governance networking policies.     

How Does Divorce Affect Iranian Women's Sexual Well-Being?

Sexuality and divorce are two interwoven subjects with complex effects on women's sexual well-being in Iranian culture. Results of this exploratory study using focus group discussions and individual interviews revealed how the sexual well-being of women was influenced by the divorce experience through common patterns and recurring themes. A total of 26 women participated voluntarily in the study. They were approached through a selected social support group in a center in West Tehran in 2011, and all had been divorced for less than 10 years. For the majority, sexuality-related matters became complicated and jeopardized their overall well-being in postdivorce life. This finding, along with the fact that the majority were seeking financial and emotional support, implies that counseling women and providing economic support for postdivorce life might improve women's sexual well-being.     

Credibility premium for rate-making systems

Credibility formula has been developed in many fields of actuarial sciences. Based upon Payandeh (2010 Payandeh, A.T. (2010). A new approach to the credibility formula. Insur.: Math. Econ. 46(2):334–338.[Crossref], [Web of Science ®] , [Google Scholar]), this article extends concept of credibility formula to relatively premium of a given rate-making system. More precisely, it calculates Payandeh’s (2010 Payandeh, A.T. (2010). A new approach to the credibility formula. Insur.: Math. Econ. 46(2):334–338.[Crossref], [Web of Science ®] , [Google Scholar]) credibility factor for zero-inflated Poisson gamma distributions with respect to several loss functions. A comparison study has been given.     

Applications and Implementation DATA-BASE MANAGEMENT SYSTEM EVALUATION AND SELECTION DECISIONS*

The rapid increase in the use of data-base management systems (DBMSs) has created a need for structured methods of evaluation and selection. This paper offers one such method. It develops a decision schema for data-base software selection that is data-model independent and contains structural associations. A decision analysis method, the analytic hierarchy process (AHP), is used to quantify the evaluation. The method developed in this paper is applied to the evaluation of two microcomputer DBMS products: dBASE II® and Condor 3®.     

A Note on Input Consistency in the Application of AHP

This is a response to the points raised by Wu [3] concerning my paper on the quantitative evaluation of data bases [4].     

Education and time investment in domestic and parental activities in urban areas of Iran

Journal of Population Research - Education is considered one of the most important determinants of population change; operating through cultural change, enhancing negotiating powers or increasing...