Estimating the Size of the Drug Market – A Critical Review of Approaches Used

Both policymakers and the public are interested in the size of the drug market. However, often both the origin and the veracity of estimates made in this area are unclear. To help understand this topic, this chapter summarizes the findings from a literature review of studies that have attempted to produce an estimate of the size of the drug market. Different methodological approaches and the challenges inherent in estimating the size of drug markets are discussed. The greatest attention is given to demand side approaches as they have been most commonly used; however, the supply side and some more recent innovative approaches are also considered. The chapter concludes by making some recommendations for future studies intended to improve the evidence base in this area.