Optimal Implementation of Intervention to Control the Self-harm Epidemic

AbstractObjectivesDeliberate self-harm (DSH) of a young person has been a matter of growing concern to parents and policymakers. Prevention and early eradication are the main interventional techniques among which prevention through reducing peer pressure has a major role in reducing the DSH epidemic. Our aim is to develop an optimal control strategy for minimizing the DSH epidemic and to assess the efficacy of the controls.MethodsWe considered a deterministic compartmental model of the DSH epidemic and two interventional techniques as the control measures. Pontryagin's Maximum Principle was used to mathematically derive the optimal controls. We also simulated the model using the forward-backward sweep method.ResultsSimulation results showed that the controls needed to be used simultaneously to reduce DSH successfully. An optimal control strategy should be adopted, depending on implementation costs for the controls.ConclusionThe long-term success of the optimum control depends on the implementation cost. If the cost is very high, the control could be used for a short term, even though it fails in the long run. The control strategy, most importantly, should be implemented as early as possible to attack a comparatively fewer number of addicted individuals

Essays in Health Economics

In the first chapter we develop a theoretical model investigating food consumption and body weight with a novel assumption regarding human caloric expenditure (i.e. metabolism), in order to investigate why individuals can be rationally trapped in an excessive weight equilibrium and why they struggle to lose weight even when offered incentives for weight-loss. This assumption allows the theoretical model to have multiple equilibria and to provide an explanation for why losing weight is so difficult even in the presence of incentives, without relying on rational addiction, time-inconsistency preferences or bounded rationality. In addition to this result we are able to characterize under which circumstances a temporary incentive can create a persistent weight loss. In the second chapter we investigate the possible contributions that social norms and peer effects had on the spread of obesity. In recent literature peer effects and social norms have been characterized as important pathways for the biological and behavioral spread of body weight, along with decreased food prices and physical activity. We add to this literature by proposing a novel concept of social norm related to what we define as social distortion in weight perception. The theoretical model shows that, in equilibrium, the effect of an increase in peers' weight on i's weight is unrelated to health concerns while it is mainly associated with social concerns. Using regional data from England we prove that such social component is significant in influencing individual weight. In the last chapter we investigate the relationship between body weight and employment probability. Using a semi-parametric regression we show that men and women employment probability do not follow a linear relationship with body mass index (BMI) but rather an inverted U-shaped one, peaking at a BMI way over the clinical threshold for overweight

An Economic Framework for User Financial Incentives for Health Behaviour Change

Background: Diseases such as stroke and heart disease are chiefly caused by unhealthy behaviours and are a major societal burden. User financial incentives are being explored as a way to encourage healthier lifestyles. This research developed a framework to provide information on pricing and cost-effectiveness of incentives and guide design of future incentive schemes. Methods: The workstreams were: a) structured, configurative literature review to identify neo-classical/behavioural economic explanations for behaviour change and incentives; b) contingent valuation survey to identify willingness to accept (WTA) and incentive pricing; c) systematic review and meta-analysis of incentives for weight loss; d) development of decision-analytic model to estimate cost-effectiveness of incentives for weight loss. Results: The reviews identified a number of factors important for understanding the effect of incentives including internal motivation, self-control and time preference. A theoretical framework of incentive impact was developed to facilitate WTA survey design. The WTA survey was completed by 112 people (n=56 at 3 months). 57% strongly disagreed with incentive use. The mean incentive required per month depended on behaviour, ranging £103.69 for smoking cessation to £45.43 for reducing alcohol intake. The most important predictors of WTA were self-control, perceived difficulty of change and attitudes to incentives. There was some evidence that WTA incentives increased over time. Review and meta-regression provided efficacy parameters for the decision-analytic model which comprised the following health states: healthy, type II diabetes, stroke, myocardial infarction and dead. Analyses from NHS and employer perspectives indicated incentives for weight loss are cost-effective over a lifetime as they dominated usual care. Discussion: Incentives may be most powerful if they are personalised to account for individual factors and attitudes and are dynamic in response to these. Incentives may be cost-effective in a number of scenarios. Further research is required on the long term outcomes of incentives and financing models

Modelling Social Dynamics (of Obesity) and Thresholds

This paper focuses on the dynamic aspects of individual behavior affected by its social embedding, either at large (society-wide norms or averages) or at a local neighborhood. The emphasis is on how initial conditions can affect the long run outcome and to derive, discuss and apply the conditions for such thresholds. For this purpose, intertemporal social pressure (from peers, from norms, or from fashions) is modelled in two different ways: (i) individual benefit is influenced by the possession of a stock (in the application: weight) and the society wide average, and (ii) individual benefits depend on a norm that follows its own motion, of course driven by agents’ behavior. The topical issue of obesity serves as motivation and corresponding models and examples are presented and analyzed

Modelling Social Dynamics (of Obesity) and Thresholds

This paper focuses on the dynamic aspects of individual behavior affected by its social embedding, either at large (society-wide norms or averages) or at a local neighborhood. The emphasis is on how initial conditions can affect the long run outcome and to derive, discuss and apply the conditions for such thresholds. For this purpose, intertemporal social pressure (from peers, from norms, or from fashions) is modelled in two different ways: (i) individual benefit is influenced by the possession of a stock (in the application: weight) and the society wide average, and (ii) individual benefits depend on a norm that follows its own motion, of course driven by agents’ behavior. The topical issue of obesity serves as motivation and corresponding models and examples are presented and analyzed.obesity; history dependence; social interactions