How is public debt the problem? If something, Japan case show that debt in your own money is not the problem. Japan economy suffers from low spending and speci

How is public debt the problem? If something, Japan case show that debt in your own money is not the problem. Japan economy suffers from low spending and specially low investment. That could be because the private sector is deleveraging of because the private sector just don't see profits investing in japan. Are not the main Japanese companies opening factories in China and other countries?