The proposed stimulus spending plans by team Obama is based on the historical actions of the FDR admin. But economists are pointing out that the WWII related spending was massive as a % of GDP. It won't work today.
From Mathew Yglesias:
One is “whether a large multiplier ever exists” and one is whether such multipliers suffer from diminishing returns. World War II spending was enormous relative to GDP. Wartime spending on that kind of scale goes way beyond the conversations we’re having right now about fiscal stimulus—the equivalent today would be something like a $5.2 trillion package rather than the $800 billion or so we’re talking about. And to get spending up to that level the government had to resort to quasi-forced savings (”war bonds”), rationing, etc.—deliberate efforts to direct production away from where demand was highest and toward the national objective of military production. The 0.8 multiplier is probably the result of diminishing returns. The question is whether you got a decent multiplier out of the first 5-10 percent of GDP you spend on stimulus. It shouldn’t surprise us if it turns out that defense spending eventually got somewhat higher than would be economically optimal in the middle of the largest war in history.