On Tuesday, President Obama signed the historic American Recovery and Reinvestment Act to avoid a spiraling economic downturn. But is it enough?

No. The Congressional Budget Office projects the U.S. economy will lose $2.9 trillion in total economic output over the next three years (PDF). To close that gap, Obama would need to sign a bill with approximately $2 trillion in total spending. But the current plan is less than $800 billion,...