All countries in the Group of Twenty (G-20—see box) have adopted discretionary fiscal packages to fight the economic downturn that was set off in mid-2007 by a financial and banking crisis with roots in the U.S. mortgage market. Those programs, enacted specifically to boost aggregate demand during the economic downturn, cost about 2 percent of the gross domestic product (GDP) of the G-20 countries in 2009 and are projected at 1.6 percent of GDP in 2010 (IMF, 2009).