Between 1986 and 1995, almost all Japanese social insurance fees were raised very substantially. Using four waves of the National Survey of Life conducted in this period, we have estimated whether or not the self-employed households changed their voluntary payment behavior regarding their social insurance fees. Given an almost 100% increase in the fees of National Pension and a 40% increase in National Health Insurance programs, our estimation suggests that their payment has not generally kept up with the increases in fees, and that a substantial proportion of the younger generation have dropped out of the social insurance system altogether.