"We can now put the elements together to form a "five-year plan" from 2009 to 2013. The path of incremental government outlays over the five years in billions of dollars is +300, +300, 0, 0, 0, which adds up to +600. The path for GDP is +120, +180, +60, minus 330, minus 330, adding up to minus 300. GDP falls overall because the famous "balanced-budget multiplier"—the response of GDP when government spending and taxes rise together—is negative. This result accords with the familiar pattern whereby countries with larger public sectors tend to grow slower over the long term.
The projected effect on other parts of GDP (consumer expenditure, private investment, net exports) is minus 180, minus 120, +60, minus 330, minus 330, which adds up to minus 900. Thus, viewed over five years, the fiscal stimulus package is a way to get an extra $600 billion of public spending at the cost of $900 billion in private expenditure. This is a bad deal.