Integrated system dynamics: Analysis of policy options for tobacco control in New Zealand

Robert Cavana, Martin Tobias


This paper addresses the conference theme of "Integrated Systems Sciences: Systems Thinking, Modeling and Practice" by providing a case study using Integrated System Dynamics. The paper uses the five phase integrated system dynamics approach outlined by Maani and Cavana involving: problem structuring, causal loop modelling [systems thinking]; dynamic modelling, scenario planning & modelling [systems modeling]; and implementation & organisational learning [systems practice]. The paper provides an overview of the system dynamics model that has been developed to assist the Ministry of Health to evaluate the dynamic consequences of tobacco control policies in New Zealand. The model consists of 4 sectors: population; smoking prevalences; second hand smoke; and tobacco attributable deaths. The model is simulated for 20-30 years into the future. The simulation package used is 'iThink', and a user interface is presented for policy analysis. A range of illustrative scenarios are provided, including: business as usual; fiscal strategies involving less affordable cigarettes; harm minimisation strategies involving either less addictive cigarettes or less toxic cigarettes; and combinations of the above policies. The main output variables (performance measures) include current smoking prevalence, tobacco consumption, and tobacco attibutable mortality. Finally areas for future model enhancement are identified.


system dynamics; dynamic simulation; tobacco policy model; tobacco control policies; New Zealand Ministry of Health

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