Andre Hofmeyr

An Item Response Theory Analysis of the Problem Gambling Severity Index

Increases in the availability of gambling heighten the need for a short screening measure of problem gambling. The Problem Gambling Severity Index (PGSI) is a brief measure that allows for the assessment of characteristics of gambling behavior and severity and its consequences. The authors evaluate the psychometric properties of the PGSI using item response theory methods in a representative sample of the urban adult population in South Africa (N = 3,000). The PGSI items were evaluated for differential item functioning (DIF) due to language translation. DIF was not detected. The PGSI was found to be unidimensional, and use of the nominal categories model provided additional information at higher values of the underlying construct relative to a simpler binary model. This study contributes to the growing literature supporting the PGSI as the screen of choice for assessing gambling problems in the general population.

Gambling Participation and Problem Gambling Severity among Rural and Peri-Urban Poor South African Adults in KwaZulu-Natal

Poor South Africans are significantly poorer and have lower employment rates than the subjects of most published research on gambling prevalence and problem gambling. Some existing work suggests relationships between gambling activity (including severity of risk for problem gambling), income, employment status and casino proximity. The objective of the study reported here is to establish the prevalence of gambling, including at risk and pathological gambling, and the profile of gambling activities in two samples of poor South African adults living in a rural and a peri-urban community. A total of 300 (150 male, 150 female) adults in KwaZulu-Natal, South Africa in communities selected using census data, completed the Problem Gambling Severity Index and a survey of socioeconomic and household information, and of gambling knowledge and activity. It was found that gambling was common, and—except for lottery participation—mostly informal or unlicensed. Significant differences between rural and peri-urban populations were found. Peri-urban subjects were slightly less poor, and gambled more and on a different and wider range of activities. Problem and at risk gamblers were disproportionately represented among the more urbanised. Casino proximity appeared largely irrelevant to gambling activity.

Mixture models of delay discounting and smoking behavior

ABSTRACT Background: Smokers exhibit an unusually high willingness to forgo a delayed reward of greater magnitude to receive a smaller, more immediate reward. The functional form of such “delay discounting” behavior is central to the discounting-based operationalization of impulsivity, and has implications for theories regarding the basis of steep discounting among smokers and treatment approaches to addiction. Objectives: We examined the discounting behavior of current smokers, ex-smokers, and never-smokers to determine whether the functional form of discounting differs between these groups. Methods: Participants completed a 27-item delay discounting questionnaire (25). We used finite mixture modeling in analyzing data as the product of two simultaneous data-generating processes (DGPs), a hyperbolic function and an exponential function, and compared results to a quasi-hyperbolic (QH) approximation, in a relatively large sample (n = 1205). Results: Consistent with prior reports, current smokers exhibited steeper discounting relative to never-smokers across exponential, hyperbolic, and QH models. A mixture model provided significant support for exponential and hyperbolic discounting in the data, and both accounted for roughly 50% of the participants’ choices. This mixture model showed a statistically significantly better fit to the data than the exponential, hyperbolic, or QH functions alone. Contrary to the prevailing view, current smokers were not more likely to discount hyperbolically than nonsmokers, and, thus, were not more prone to time-inconsistent discounting. Conclusions: The results inform the interpretation of steep discounting among smokers and suggest that treatment approaches could be tailored to the type of discounting behavior that smokers exhibit.

Criterion-related and construct validity of the Problem Gambling Severity Index in a sample of South African gamblers

The Problem Gambling Severity Index, the scored module of the Canadian Problem Gambling Index, is a population-based survey instrument that is becoming the preferred epidemiological tool for estimating the prevalence of disordered gambling. While some validation evidence for the Problem Gambling Severity Index is available, very little is known about its psychometric characteristics in developing countries or in countries the populations of which are not highly Westernised. The aim of this study was to investigate the validity of the Problem Gambling Severity Index with a specific focus on its criterion-related and construct (concurrent) validity in a community sample of gamblers in South Africa (n = 127). To this end, the Problem Gambling Severity Index was administered alongside the Diagnostic Interview for Gambling Severity and measures known to associate with gambling severity (impulsivity, current debt, social problems, financial loss, race, sex). Results showed that the Problem Gambling Severity Index was predictive of Diagnostic Interview for Gambling Severity diagnosis from both a categorical and dimensional point of view and demonstrated high discrimination accuracy for subjects with problem gambling. Analysis of sensitivity and specificity at different cut-points suggests that a slightly lower Problem Gambling Severity Index score may be used as a screening cut-off for problem gambling among South African gamblers. The Problem Gambling Severity Index also showed significant correlations with the Barratt Impulsiveness Scale, a widely known measure of impulsivity, and with some of the predicted behavioural variables of interest (gambling activities, money lost to gambling, current debt, interpersonal conflict). This article therefore demonstrates initial criterion and concurrent validity for the Problem Gambling Severity Index for use in South African samples.

Addressing problem gambling: South Africa's National Responsible Gambling Programme.

In the English-speaking world and some parts of Europe, problem and pathological gambling are treated as a significant public health problem. At the same time, these jurisdictions recognise that for most of those who engage in it, gambling is a harmless leisure activity that may yield public benefits by contributing more in taxation than other leisure industries and/or contributing to out-of-town tourism. Strategies that combine minimising the harm caused with maximising the benefits of gambling are therefore crucial for good public policy. Such lessons may also be relevant to other legal and illegal industries, such as those involving the production and sales of alcohol, where analogous harms and benefits exist.

Two Sides of the Same Coin: Re-examining Nepotism and Discrimination in a Segmented Society

Abstract We report the results from a series of trust games designed to distinguish racial discrimination from racial nepotism, played with a sample of high school students in Cape Town, South Africa. In contrast to the original work in this regard by Fershtman et al. (2005), we find considerably greater heterogeneity in the way that proposers respond to the revealed racial identity of their partner, with nepotism being a dominant behavior. However, while some proposers exhibit a nepotistic bias in their offers that favors in-group members on average, others exhibit a nepotistic strategy that favors out-group members. A consequence of this nepotism is that both efficiency and equity are reduced on average.