Mathematical modelling of health impacts

[...]good quality primary studies on the effects of change. 5 Even where there is good evidence of a causal relation, reversibility cannot be assumed 7 : as a quantified illustration, the magnitude of the effect of a rise or a fall in cigarette price on cigarette consumption (the elasticities) differ. 8 In relation to socioeconomic inequalities, while cross sectional studies of unemployment and health are subject to direct and indirect selection effects, 9 factory closure studies overcome this problem, 10 but do not directly answer the question, "how much health gain would be expected from the creation of a certain number of jobs?"-which arises frequently in the context of health impact assessment.