Interest rates will remain at very low level for a long time and central banks could continue using quantative easing (QE) tools in the future, as the zero lower bound will remain binding in the medium-term, a report by the Bank of Greece said on Thursday. The report was presented by Dimitris Malliaropoulos, director of the Economic Analysis and Studies Department of the Bank of Greece during a congress organised by the National Bank of Albania and the London School of Economics and Political Science in Tirana. The report also noted that central banks must re-assess the benefits from preserving their assets at their current high levels (according to accumulated accounts of the US Federal Reserve, the European Central Bank, the Bank of England and the Bank of Japan central banks have almost quadrupled their assets since 2007 in their efforts to deal with a global financial crisis).