Horizontal inequity in health care utilization in Japan.

International comparisons of horizontal inequity in health has recently become one of the most pertinent issues in health economics. However, no previous studies have been undertaken on Japan. This omission is rectified in this paper. Moreover, we consider the dynamics of horizontal inequity in health over six years from 1992 to 1998. These dynamics have never been considered in this field. In a rigorous international comparison, though we cannot find any horizontal inequity in health in 1998, we find pro-rich inequity before 1995. The reason for this may be the reform of the health insurance system in 1997.