But sometimes they aren’t, most notably around the time of the onset of the financial crisis in 2007– 08, when estimates of the neutral rate declined rapidly and significantly. Currently, there is a debate in the US as to whether the neutral rate of interest has bottomed and is shifting up.
This raises the question as to the degree and speed with which such a movement in the neutral rate in the US might translate globally. All of these questions highlight to me the inherent uncertainty about the future evolution of interest rates.