The purpose of this paper is to describe the research method of meta-analysis and to use meta-analytical techniques to observe contextual and methodological constraints which are as many sources of divergences between the estimates of health costs of air pollution. Indeed, meta-analysis is a research method to summarize, evaluate and analyse previously obtained research results. Although it has been first employed for medical sciences, it is increasingly used in economics as a complement to a state of the art literature review.

Results issuing from ordinary least squares estimators suggest that the health costs associated with air pollution crucially depend both on the applied method of valuation and on the specification of the model.