Central banks across the developing world are pushing policy to extremes that would have been unimaginable a few weeks ago, as the coronavirus crisis sends debt markets into turmoil and governments prepare for an unprecedented expansion of public spending.

The central banks of Poland, Colombia, the Philippines and South Africa have all begun to buy government and private sector bonds on secondary markets, while the central banks of Brazil and the Czech Republic have asked for new laws to allow them to do so. 

Such policies, known as quantitative easing, were used by the US Federal Reserve and other central banks in the G7 group of wealthy nations after the global financial crisis of 2008-09, as other ways of loosening monetary policy such as cutting interest rates failed to reignite their economies.