When did long-term interest rates stop keeping pace with expected inflation?

One after the other, central banks are moving to "yield curve control", controlling long-term interest rates. The goal is to make monetary policy more effective and to ensure borrower solvency. Given the implementation of this policy, long-term interest rates no longer react to their usual determinants. In particular, the effect of changes in expected inflation on long-term interest rates disappears. We therefore look at the relationship between changes in expected inflation and changes in the long-term interest rate. Expected inflation has had no effect on long-term interest rates since:  2018 in Japan;  Early 2020 in the euro zone;  Early 2020 in the United States, which provides an estimate of the effective date of implementation of yield curve control.