"Nobody knows" is too simplistic a take. Nobody knows when they don't know anymore is more accurate. A better way to describe the situation is that most mainst

"Nobody knows" is too simplistic a take. Nobody knows when they don't know anymore is more accurate. A better way to describe the situation is that most mainstream established macroeconomic theories/models work only conditionally. They match reality accurately only in certain periods, on the condition that myriad of other factors doesn't become important. Over time, some excluded variables become important. The explanatory power of the old model erodes. When the theory is finalized and explains the situation for the era it was created, it may be already outdated. Inflation expectations theory works reasonably well for fast growth, increasing labor force industrial era. It's not so good in 2% annual GPD growth, aging or slowly growing labor force era. The new school of economists thinks that that inflation is not likely to be a long-term problem. Fed will be back in trying to get inflation up in 1-2 years. Old school economists who look at the older models and data from 50-90s think that expectations will keep inflation going once it starts.