There might be a surprisingly simple answer to that challenging question. Indeed, 67 central banks have inflation targets by now and they use different narratives for their common anchor, but the naked truth is the same.
The real reason is not that central banking is an art, not science, /Martin Wolf, FT, 3 March 2021/ just on the contrary.
Central banking’s closest relatives can be found in quantum physics, where Heisenberg’s uncertainty principle, Bohr’s and Schrödinger’s games are constantly played by particles.
Indeed, a deep awareness of uncertainty /Martin Wolf/ has been playing the major role in inflation targeting. In the 1990s, especially after 1996, the speed and complexity of the unfolding new information age challenged central banks’ traditional thinking. The old world of Newton disappeared and the new quantum world arrived.
The measurement of inflation became as complex and uncertain as measuring the speed and present place of a piece of information.
The quantum laws of inflation are close to the quantum world of the Information Age. We understood that it was the simplest, most practical solution to use a family member to follow the games of the brave new world.
Governor Matolcsy, MNB, the Central bank of Hungary