Browsing by Author "Kincaid, Harold"

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    A low-cost, low-intensity contingency management smoking cessation programme with students: Experimental evidence
    (2018) Rusch, Olivia; Kincaid, Harold
    Tobacco consumption is a pressing global issue, leading to more than five million deaths each year. In South Africa, the smoking prevalence rate is stubbornly high, implying that a successful smoking cessation programme could have large social benefits, particularly if it targets young smokers. Contingency management interventions, which provide cash transfers conditional on biochemically-verified abstinence, have been effective in bringing about increased smoking cessation rates. However, contingency management programmes are typically very costly and involve frequent monitoring. This dissertation presents results of randomised controlled trial evaluating a low-cost, low-intensity contingency management smoking cessation programme conducted on a sample of treatment-seeking student smokers at the University of Cape Town in 2017. There is a statistically significant treatment effect, that is robust across multiple specifications, which increases the likelihood of abstinence by 13- 20%. In addition, the programme as a whole decreased the smoking intensity of non-abstainers. This study suggests, therefore, that a low-cost, low-intensity contingency management smoking cessation programme is efficacious in promoting abstinence amongst treatment-seeking students, and that it should be added to the tobacco control toolkit in South Africa.
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    A taxometric analysis of problem gambling data from a South African national urban sample
    (Journal of Gambling Studies, 2015-05-28) Kincaid, Harold; Daniels, Reza Che; Dellis, Andrew; Hofmeyr, Andre; Sharp, Carla; Rousseau, Jacques; Ross, Don
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    Analysing Risk Preferences and Time Preferences with respect to Smoking Status and Smoking Intensity
    (2019) Preston, Charles; Hofmeyr, Andre; Kincaid, Harold
    Smoking is a leading cause of death worldwide, and thus the behavioural components need to be understood to mitigate the damage caused by the practice. The relationship between smoking and factors such as risk preferences and time preferences has been the subject of a growing body of literature. This paper evaluates experimental data from smokers and nonsmokers at the University of Cape Town collected in 2016 and 2017. Maximum likelihood estimation is used to estimate models of risk preferences and time preferences. The results highlight that smokers are less risk averse than non-smokers; that smokers discount more heavily than non-smokers; that greater smoking intensity is correlated with lower risk aversion; and that greater smoking intensity is not related to discounting behaviour. In some specifications the relationship between smoking intensity and risk aversion is parabolic, and as such moderate smokers are less risk averse than heavy smokers and light smokers. In conclusion, smokers tend to discount more heavily than non-smokers, and lower smoking intensity is associated with greater risk aversion than higher smoking intensity.
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    Describing the determinants of problem gaming in South Africa : a longitudinal approach
    (2015) Rosenberg, Samantha Claire; Kincaid, Harold
    In this study, an enhanced model describing the temporal determinants of problem gambling in South Africa is established using the National Longitudinal Study of Gambling Behaviour (NLSGB) dataset. Various conceptual ambiguities evidenced in the literature, particularly those associated with the Problem Gambling Severity Index (PGSI) screen, are explored. Gambling severity classification, as per the PGSI, is unstable over time. Evidence suggests that the standard PGSI cut-off score of 8 may be replaced by a score of 10 in some cases. For robustness, concurrent use of the PGSI and the Diagnostic and Statistical Manual of Mental Disorders (DSM) measurement criteria for problem gambling is advised. Although it remains undetermined whether problem gambling is best understood as an ordinal or a continuous disorder, the bounded natures of the PGSI and DSM scoring-systems make the statistical analyses of these tools most consistent with an ordinal structure; use of continuous structures cause statistical complications.
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    An experimental analysis of the risk-trust confound
    (2017) Chetty, Rinelle; Hofmeyr, Andre; Kincaid, Harold
    The notion of trust has great significance to an economy. Trust is known to be associated with efficient judicial systems, improved government functioning with lower corruption, and better financial outcomes (Johnson and Mislin, 2011). However, many researchers have argued that risk attitudes may confound the measurement of trust because trusting decisions involve outcomes that have only some probability of occurring. This study therefore seeks to question whether risk attitudes predict trusting decisions in the Berg, Dickhaut and McCabe (1995) Investment Game amongst students at the University of Cape Town in 2016. The statistical method adopted is maximum likelihood estimation which accounts for subject errors in decision making. This study finds that having additional information on the past behaviour of trustees does not affect the trusting behaviour of trustors. In addition, the presence of a human trustee, versus a computer, is found to significantly influence behaviour and decisions made by trustors in the trust game. It is also found that subjects are, on average, risk averse with 62% of subjects exhibiting high levels of risk aversion, and females being more risk averse than males. Subjects were also found to subjectively distort probabilities, where subjects would overweight low probabilities and underweight moderate to high probabilities. Expected Utility models and Rank-Dependent Utility models show that risk and trust are statistically significantly related and that the reasons for trusting one's partner may have arisen out of an inner need to simply trust that person. In addition, risk preferences were able to predict trusting decisions in the environment of risk and the environment of trust. Risk and trust therefore go hand-in-hand and it can be argued that trusting decisions are perceived as decisions involving risk. This study therefore finds that trusting decisions are in fact confounded by risk attitudes, so that a subject may be seen as trusting when actually they are just risk-seeking, or seen as non-trusting when they are just simply risk averse.
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    The demand side of clientelism: The role of client’s perceptions and values
    (2015-05-28) Pellicer, Miquel; Wegner, Eva; Benstead, Lindsay; Kincaid, Harold; Lust, Ellen; Vasquez, Juanita