Can the same model as before COVID be used to forecast inflation?

Concern is sometimes expressed that if central banks or other institutions are forecasting a fairly rapid decline in inflation, it is because they are using tools (models) that are estimated and based on the pre-COVID period when there was no inflation. If the transition to an inflationary environment has changed behaviour s and expectations, then these models may no longer adequately forecast inflation today. We test this argument by looking at whether equations that predict wage and price growth estimated over a period beginning in 1998 correctly predict what happened in 2020 and 2021 in the United States and the euro zone. If the answer is yes, then the argument that inflation forecasting tools are obsolete is wrong. We find that : In the United States and the euro zone, inflation in 2021 was higher than that predicted by the estimated equations from 1998 to 2019 or 2021; In the United States but not in the euro zone, nominal wage growth was higher than predicted. Altogether, wage and price formation does seem to be different in 2021 than in the past in the United States.