Omega model for a jump–diffusion process with a two-step premium rate

In this paper, a jump–diffusion Omega model with a two-step premium rate is studied. In this model, the surplus process is a perturbation of a compound Poisson process by a Brown motion. Firstly, using the strong Markov property, the integro-differential equations for the Gerber–Shiu expected discounted penalty function and the bankruptcy probability are derived. Secondly, for a constant bankruptcy rate function, the renewal equations satisfied by the Gerber–Shiu expected discounted penalty function are obtained, and by iteration, the closed-form solutions of the function are also given. Further, the explicit solutions of the Gerber–Shiu expected discounted penalty function are obtained when the individual claim size is subject to exponential distribution. Finally, a numerical example is presented to illustrate some properties of the model.     

Life table estimator revisited

We explore the standard life table (actuarial) estimator for grouped right-censored survival data and its extensions in order to consider its relationship with the Kaplan–Meier estimator, and to investigate the critical properties of the extended life table estimators (ELTEs). We discuss certain conditions for the ELTE to be consistent and develop a characterization of the standard life table estimator using the consistency property under any choice of at least two observation times of a finite interval. We also perform a comparative analysis of the ELTEs with the corresponding maximum likelihood estimators for grouped right-censored survival data.     

Shapiro–Wilk test for skew normal distributions based on data transformations

A probability property that connects the skew normal (SN) distribution with the normal distribution is used for proposing a goodness-of-fit test for the composite null hypothesis that a random sample follows an SN distribution with unknown parameters. The random sample is transformed to approximately normal random variables, and then the Shapiro–Wilk test is used for testing normality. The implementation of this test does not require neither parametric bootstrap nor the use of tables for different values of the slant parameter. An additional test for the same problem, based on a property that relates the gamma and SN distributions, is also introduced. The results of a power study conducted by the Monte Carlo simulation show some good properties of the proposed tests in comparison to existing tests for the same problem.     

Strategies for work–family balance in a South African context

ABSTRACT

Finding and maintaining work–family balance has become an increasingly difficult challenge for South African families due to various factors, including economic, political, social and cultural changes that can impact negatively on family well-being. While pathways and strategies for work–family balance have been identified in other contexts, there is little available research on the topic in a South African context. Considering the knowledge that South African social workers have in this regard as a result of their training, qualifications and role in the South African context, South African social workers were selected as participants. The aim of this study was therefore to explore and describe, from the perspective of a group of South African social workers, strategies for work–family balance that can potentially contribute to family well-being in a South African context. A narrative inquiry research design was implemented. Thirteen female social workers between the ages of 23 and 46 who work in different social work contexts across South Africa were recruited by means of purposive and snowball/network sampling. Data were collected by means of written narratives and analysed by thematic analysis. The findings identify the following strategies: Setting clear boundaries, open communication in work and family domains, strengthening personal and professional support systems, planning, time management and prioritising, self-care, reasonable work environment and continuous personal and family assessment. While the findings share similarities with work–family balance strategies identified in other contexts, this study’s significance lies in the fact that it identifies strategies specifically for the South African context and that it does so from the perspective of South African social workers.     

Using point optimal test of a simple null hypothesis for testing a composite null hypothesis via maximized Monte Carlo approach

King’s Point Optimal (PO) test of a simple null hypothesis is useful in a number of ways, for example it can be used to trace the power envelope against which existing tests can be compared. However, this test cannot always be constructed when testing a composite null hypothesis. It is suggested in the literature that approximate PO (APO) tests can overcome this problem, but they also have some drawbacks. This paper investigates if King’s PO test can be used for testing a composite null in the presence of nuisance parameters via a maximized Monte Carlo (MMC) approach, with encouraging results.     

Pricing dynamic fund protections for a hyperexponential jump diffusion process

This article deals with the valuation of dynamic fund protections (DFPs) under a jump diffusion model, where the jump size follows a hyperexponential distribution. The closed-form solution of the value of DFP is obtained in terms of Laplace transform. A numerical example is provided to show that the explicit solution is easy to implement by using the Gaver–Stehfest algorithm. Effects of key parameters are analyzed at last. The valuation method developed in this work can be used in pricing various variable annuities and path-dependent financial products.     

Poisson–exponential distribution: different methods of estimation

In this study, we present different estimation procedures for the parameters of the Poisson–exponential distribution, such as the maximum likelihood, method of moments, modified moments, ordinary and weighted least-squares, percentile, maximum product of spacings, Cramer–von Mises and the Anderson–Darling maximum goodness-of-fit estimators and compare them using extensive numerical simulations. We showed that the Anderson–Darling estimator is the most efficient for estimating the parameters of the proposed distribution. Our proposed methodology was also illustrated in three real data sets related to the minimum, average and the maximum flows during October at São Carlos River in Brazil demonstrating that the PE distribution is a simple alternative to be used in hydrological applications.     

The economic effects of carbon tax on China’s provinces

The responsibility for carbon emissions tends to be different under different emission accounting principles. By applying the latest 2012 Chinese multi-regional input–output table, this study evaluated the impacts of carbon tax on tax burdens and sectoral competitiveness in Chinese provinces when considering either production-based or consumption-based emissions. Our results indicated that, in the scenario of cutting production tax for carbon tax, the developed provinces, such as Beijing, Shanghai, Zhejiang, and Jiangsu, who are much bigger payers of production tax, are net beneficiaries of carbon tax. In contrast, recycling the tax revenues to low-income households makes the less-developed provinces in the central and western China become net revenue receivers. Furthermore, for competitiveness effects, the emission intensive sectors, such as Electricity and hot water production and supply, Petroleum and gas, and Metal products, are impacted vitally under both accounting principles in all provinces. Nevertheless, compared with the production-based principle, a consumption-based carbon tax could reduce the unfavorable competitiveness effects of most affected sectors in the less-developed provinces, while slightly increasing those effects in the developed provinces. Our results provide new information on the regional impacts of carbon tax based two different accounting principles with different tax revenue recycling scenarios.     

Are good governance principles institutionalised with policy transfer? An examination of public–private partnerships policy promotion in China

This article explores the following question: To what extent are good governance principles being institutionalised in China as a result of public–private partnerships (PPP) policy transfer? Since 2013, China has been pursuing PPP and applying aspects of related good governance drawing from Western experience despite its radically different fragmented authoritarian regime. This makes China a unique case to observe the extent to which good governance principles can be institutionalised in very different contexts. This article assesses the degree of institutionalisation of three good governance principles that guide PPP policy elsewhere: transparency and accountability, willingness to collaborate and equity between partners. It argues that while the PPP policies have been applied extensively in recent years, these good governance principles have been institutionalised to varying degrees as they have had to be adapted and compromised to fit with existing power relations in authoritarian China. The findings aim to add value to the literature regarding PPP policy transfer and good governance, by revealing the challenges of institutionalising good governance principles through PPP policy transfer in an alien context.