A Comparative Study of the Market Configuration of the Japanese Pharmaceutical Market Using the Gini Coefficient and Herfindahl–Hirschman Index

Background: As of 2015, the Japanese pharmaceutical market was the world’s third largest pharmaceutical market. Although previous studies have examined market differences in terms of market size and pricing policy, little is known about comparative market configurations. The present study provides a comparative analysis of pharmaceutical market configurations in Japan and five other markets. Methods: Based on data for the 100 top-selling drugs in 2014 in Japan, the United States, the United Kingdom, France, Germany, and the global market, we explored differences in market configurations using the Herfindahl–Hirschman Index, Lorenz curves, and Gini coefficients. We also investigated market trends by analyzing changes in sales, sales volume, and price. Results: The 100 top-selling drugs accounted for a lower share of the total market in Japan, France, and Germany as compared to the United States and the United Kingdom. The market deviation of the 100 top-selling drugs indicated by the Herfindahl–Hirschman Index and Gini coefficient was smallest in Japan. Sales of most of the top-100 drugs increased in all the countries studied; however, directional price changes differed by country and sales volume trend. Conclusion: Our findings showed that market deviations in Japan were relatively low compared with those in other developed countries, suggesting that some of the more beneficial drugs in other developed countries obtain relatively fewer benefits from the Japanese pharmaceutical market, and some less beneficial drugs obtained more benefits.