A growing number of economists hold the view that the US government’s growing debt is nothing to worry about. They believe this because real interest rates are not only historically low but are also forecast to stay low for a long time. As such, the government can carry high debt levels without worrying about debt sustainability. In addition, some economists argue that, in countries where low real interest rates and the negative interest-rate-minus-growth differential are sustained, the government can increase primary deficits without worrying about future costs. However, a deeper fact should worry economists more than it does - namely, it is hard for government to make good policies when it swells so large that it has little practical choice but to depend on annual deficit financing. In particular, high and growing levels of public debt are likely to induce higher inflation while the growing burden of debt and deficit financing increases political pressure to continue pursuing inflationary policy. High debt levels also make inflation harder to control if it becomes persistent.