Economist Martin Wolf cites as an example the U.S., where sudden shifts in the private sector from deficit to surplus due to the Great Recession forced the government balance into deficit. "The financial balance of the private sector shifted towards surplus by the almost unbelievable cumulative total of 11.2 per cent of gross domestic product between the third quarter of 2007 and the second quarter of 2009, which was when the financial deficit of US government (federal and state) reached its peak...No fiscal policy changes explain the collapse into massive fiscal deficit between 2007 and 2009, because there was none of any importance. The collapse is explained by the massive shift of the private sector from financial deficit into surplus or, in other words, from boom to bust."
