What would a normalisation of real long-term interest rates entail?

We look at the evolution of real long-term interest rates (calculated with long-term inflation expectations) in the United States and the euro zone. If the shift to a more inflationary economic equilibrium characterised by many scarcities leads to a normalisation of monetary policies, how high will real long-term interest rates go? What reference should be used to determine this? It is well known that the neutral real interest rate, which results from the savings-investment equilibrium, makes no sense in an open economy with high capital mobility; Does the real long-term interest rate follow a similar path to potential growth in the medium term? The answer is yes; How high was the real long-term interest rate on average in the past when there were monetary cycles linked to inflation? We see that at the time, real long-term interest rates were clearly positive: on average 1.3% in the United States and 1.7% in the euro zone.