How high must interest rates be to combat inflation?

We examine the situations of the United States and the euro zone: how high would central banks have to raise interest rates in order to have a noticeable effect on inflation? We examine past trends in interest rates (nominal and real) and inflation and conclude that for monetary policy to rapidly lower inflation (in one to two years), nominal interest rates would have to be: At least 3 percentage points higher than inflation in the United States; Similar to inflation in the euro zone.