The global financial crisis that erupted in 2008 transformed the role of central bankers and the scale and scope of their policy toolkit. Today, financial stability is once again at the core of central banks’ missions, and interest rates in a number of rich countries are likely to remain at or even below zero for some time.

This means that central bankers’ actions will be more visible and politically sensitive than they were even a decade ago. And that poses a growing threat to one of the great institutional innovations of the late twentieth century: central-bank independence.