Is our national debt finally too much? (update)

National debt levels and their impact on economic growth remain a subject of intense debate among economists. The 2010 Reinhart and Rogoff paper, which suggested a 90% debt-to-GDP ratio as a dangerous threshold, significantly influenced global fiscal policy and austerity agendas. However, subsequent research clarified that the correlation between high debt and slow growth does not prove causation, as low growth can also drive debt accumulation. With U.S. national debt surpassing $40 trillion and interest rates rising, experts like Karen Dynan and Kenneth Rogoff argue that the primary risk is the escalating cost of servicing this debt. While no definitive "red line" exists, current trends indicate that the U.S. is on an unsustainable trajectory, necessitating difficult political choices regarding spending and taxation to avoid future economic instability.