Here's a quiz. Since January 2009, the size of the Federal Reserve's balance sheet has risen by: (a) 15 percent: (b) 30 percent; (c) 100 percent; (d) 200 percent.

To hear critics tell it, you'd think the answer would be (d). Last week, former Minnesota Governor Tim Pawlenty, a prospective presidential candidate, complained that the injection of "fiat money" was devaluing the dollar. The news has been filled with the Federal Reserve's loud efforts to inject cash into the economy by expanding its balance sheet — i.e., by creating fiat money. These include the purchase of $1.25 trillion in mortgage-backed securities in 2009 (QE1), and the current drive to buy $600 billion of government bonds (QE2).

As my colleague Aaron Task correctly answers in the accompanying video, however, the answer is actually (b) 30 percent. Last week the Fed had $2.627 trillion in assets (see item 8 in the report), compared with $2.041 trillion in January 2009.