Japan has an aging population, and the government has enormous transfer programs that benefit seniors, increasing strains on the government’s already bloated budget. Sounds familiar. ImageExcept, Japan is much further along in that demographic transition than the United States. …Because of that larger senior population, Japan has much higher public debt than the United States, as a share of the economy. The U.S. national debt is around 120 percent of gross domestic product. Japan’s is around 250 percent of GDP, higher than any other developed country. …And yet, Japan’s staggering debt load has not caused a major crisis.