Hedonic Analysis of Arthritis Drugs

We examine the relationship between quality'' and market outcomes for a group of drugs used to treat rheumatoid arthritis. Though this is a widespread and debilitating disease with very substantial impacts on the health of patients and on the economy, currently available drugs have limited efficacy and serious side effects. Clinical research conducted since these products were approved has resulted in substantial revisions to the body of scientific information available to physicians. The relative quality' of these drugs (as captured by efficacy and toxicity measurements reported in peer-reviewed clinical trials) has changed markedly over the past 15 years. Yet in our analysis of US wholesale prices we find that relative prices appear to be only weakly related to quality. We do however find a relationship between changes in reported efficacy and toxicity and the evolution of quantity shares in this market.