Bernanke attacked for 'too low" interest rates The BIS said central banks, mostly in emerging economies, have amassed $18 trillion (£11 trillion) in assets or 30pc of global GDP, a fourfold increase in a decade. While this did fuel the global asset boom, it did not absolve Western central banks of their own responsibility. Policy was even looser in emerging economies where rates were 5pc too low by 2008, typically because they had pegged their currencies to the dollar in one way or another. They were importing a monetary policy that was out of step with the needs of fast-growing tiger economies. The report did not name institutions, but it clearly meant the Fed and the European Central Bank. Both ran negative real interest rates as the boom gathered pace. The BIS criticised the ideology of the Bernanke Fed that central banks should let asset bubbles run their course, confining their role to cleaning up afterwards. This created an "asymmetric response pattern" or moral hazard. "Central banks need to reconsider their monetary policy frameworks with a view to ensuring symmetry over the financial cycle," it said. Separately, the BIS reported a 30pc plunge in issuance of international debt securities to $1,828bn in the second quarter, largely due to frantic deleveraging in Europe. Eurozone financial groups repaid a net €110bn from April to June. The US and emerging markets cut new issuance sharply as the global slowdown gathered pace. The BIS said international banks withdrew a further $92bn from Greece, Ireland, Italy, Portugal and Spain, evidence that the ECB's $1 trillion blitz of cheap lending to banks failed to unlock interbank funding.