The perils of asking central banks to do too much

THE PARLIAMENTARY act that chartered the Bank of England in 1694 begins by describing the motivation of its authors, “to promote the publick Good and Benefit of our People”. Ideas about how best the bank can serve the publick have changed a bit over the centuries, from managing the market for government debt, to maintaining the value of sterling against gold, to, in recent decades, keeping inflation in the region of 2%. On March 3rd its mandate received another tweak, when Rishi Sunak, the chancellor, declared that it should conduct policy with an eye towards environmental sustainability. The adjustment is just one example of a wider phenomenon, in which central banks are told to accept, or themselves take on, tasks beyond the standard monetary ambit. The mission creep is enabled by a sense that central banks can and should do more, given their firepower and competence compared with some other government officials. But tempting as it is to allow authority to flow to those who use it well, adding to central-bank mandates poses both economic and political risks.