The European Central Bank (ECB) President Mario Draghi said at a conference of economists and central bankers in Frankfurt on Wednesday that bond purchases should help to boost inflation and encourage investors to shift to riskier assets. He noted that quantitative easing was unconventional but "not unorthodox".

Draghi rejected criticism that the ECB should implement quantitative easing sooner. He pointed out that the ECB has introduced a negative rate on bank deposits parked at the ECB and has purchased covered bank bonds and asset-backed securities.

The ECB had started to purchase government bonds on Monday.