These low interest rates have in turn fuelled economic booms, encouraging excessive risk taking. Booms have then turned to busts, which policymakers have responded to with even lower rates. Claudio Borio, head of the organisation’s monetary and economic department, said: “Persistent exceptionally low rates reflect the central banks’ and market participants’ response to the unusually weak post-crisis recovery as they fumble in the dark in search of new certainties.”

“Rather than just reflecting the current weakness, they may in part have contributed to it by fuelling costly financial booms and busts and delaying adjustment. The result is too much debt, too little growth and too low interest rates. In short, low rates beget lower rates."

The BIS warned that interest rates have now been so low for so long that central banks are unequipped to fight the next crises. “In some jurisdictions, monetary policy is already testing its outer limits, to the point of stretching the boundaries of the unthinkable,” the BIS said. Policymakers in the eurozone, Denmark, Sweden and Switzerland have taken their interest rates below zero in an attempt to support their economies, contributing to a decline in bond yields.