From a new paper by St. Louis Fed President James Bullard:
The Federal Reserve Bank of St. Louis is changing its characterization of the U.S. macroeconomic and monetary policy outlook. An older narrative that the Bank has been using since the financial crisis ended has now likely outlived its usefulness, and so it is being replaced by a new narrative. The hallmark of the new narrative is to think of medium- and longer-term macroeconomic outcomes in terms of regimes. The concept of a single, long-run steady state to which the economy is converging is abandoned, and is replaced by a set of possible regimes that the economy may visit. Regimes are generally viewed as persistent, and optimal monetary policy is viewed as regime dependent. Switches between regimes are viewed as not forecastable.
It is a good time to consider a regime-based conception of medium- and longer-term macroeconomic outcomes. Key macroeconomic variables including real output growth, the unemployment rate, and inflation appear to be at or near values that are likely to persist over the forecast horizon. Any further cyclical adjustment going forward is likely to be relatively minor. We therefore think of the current values for real output growth, the unemployment rate, and inflation as being close to the mean outcome of the “current regime.”
Of course, the situation can and will change in the future, but exactly how is difficult to predict. Therefore, the best that we can do today is to forecast that the current regime will persist and set policy appropriately for this regime. If there is a switch to a new regime in the future, then that will likely affect all variables—including the policy rate—but such a switch is not forecastable.