"The Covid-19 strain of the coronavirus has transformed economic prospects as rapidly as it has comprehensively. And in the main this is because lockdowns have been the economic tool by which we have chosen to control the virus. World growth is not only going to stall this year but move significantly into reverse. Year on year growth in world income for three decades has hovered in the range 3 to 4% and even in the worst year of the financial crisis barely crossed the zero line and yet we now expect output to contract by some 3-4% this year and that is probably one of the better case scenarios. Any return to the 'blessed' pre-Covid-19 world may have to be staggered and necessitate a comprehensive re-think of economic practice. "