In a new blog post, the European Central Bank (ECB) presents research arguing that central banks can generally retain control of inflation despite high public debt, but must account for its effect on interest rates consistent with price stability. The analysis suggests adjusting rates directly as debt increases rather than waiting for inflation to rise. Higher debt raises the natural rate of interest, the rate that balances demand with the economy’s productive capacity and keeps inflation on target. The mechanism depends on households spending some transfers financed by debt rather than saving the entire amount in anticipation of future taxes. Public debt then increases household wealth and spending, creating inflationary pressure. Raising rates only in response to higher inflation can prove less effective because tightening also increases future debt, generating further price pressures. Stronger tightening can therefore make inflation more persistent and reduce cumulative inflation only slightly, or even increase it. The research also identifies a theoretical debt limit beyond which even very high interest rates cannot restrain household spending. At sufficiently high debt levels, higher interest income can encourage consumption by reducing the savings households need to sustain future spending. The main model estimate places this limit at about 5.4 times annual gross domestic product, far above current advanced economy debt ratios.
ECB blog examines why higher public debt requires higher interest rates for price stability
In a blog post, the European Central Bank examines why higher public debt can require higher interest rates to maintain price stability. The analysis suggests adjusting rates as debt rises rather than waiting for inflation, since tightening can itself increase future debt and prolong price pressures. Its main model estimate places the debt limit beyond which rates cannot restrain spending at about 5.4 times annual gross domestic product, far above current advanced economy ratios.