Central bankers from around the world have issued a joint statement of support for US Federal Reserve Chair Jerome Powell, as he faces a criminal probe on top of mounting pressure from US President Donald Trump to resign early.

It is very unusual for the world’s central bank governors to issue such a statement. But these are very unusual times.

The reason so many senior central bankers – from Australia, Brazil, Canada, Europe, New Zealand, South Africa, South Korea, the United Kingdom and other countries, as well as the central banks’ club the Bank for International Settlements – have spoken up is simple. US interest rate decisions have an impact around the world. They don’t want a dangerous precedent set.

Over the course of my career as an economist, much of it at the Reserve Bank of Australia and the Bank for International Settlements, I have seen independent central banks become the global norm in recent decades.

Allowing central banks to set interest rates to achieve inflation targets has avoided a repeat of the sustained high inflation which broke out in the 1970s.

Returning the setting of monetary policy to a politician, especially one as unpredictable as Trump, is an unwelcome prospect.

Trump has repeatedly attacked the US Federal Reserve (known as the Fed) over many years. He has

© The Conversation