We pointed to some economists' responses to the Fed's quantitative easing efforts earlier today.  But we just read Federal Reserve Chair Ben Bernanke's own explanation for why the Fed is taking this approach.  Bernanke shared his reasoning in an op-ed for the Washington Post, and the strategy--whether you agree with it or not--comes across much more clearly than reading the FOMC's announcement.  Bernanke writes:

The FOMC decided this week that, with unemployment high and inflation very low, further support to the economy is needed. With short-term interest rates already about as low as they can go, the FOMC agreed to deliver that support by purchasing additional longer-term securities, as it did in 2008 and 2009. The FOMC intends to buy an additional $600 billion of longer-term Treasury securities by mid-2011 and will continue to reinvest repayments of principal on its holdings of securities, as it has been doing since August.

This approach eased financial conditions in the past and, so far, looks to be effective again. Stock prices rose and long-term interest rates fell when investors began to anticipate the most recent action. Easier financial conditions will promote economic growth. For example, lower mortgage rates will make housing more affordable and allow more homeowners to refinance. Lower corporate bond rates will encourage investment. And higher stock prices will boost consumer wealth and help increase confidence, which can also spur spending. Increased spending will lead to higher incomes and profits that, in a virtuous circle, will further support economic expansion.

Read What the Fed did and why: supporting the recovery and sustaining price stability here.

And if you are looking for clearer language on the Fed's policy, Planet Money tried an interesting approach.  They took the FOMC announcement, and have translated it into what they call "plain English."  "Plain English," as it turns out, includes some sarcasm.  But this might still be a helpful way to make sense of the action.  For example, where the Fed release has this language:

To promote a stronger pace of economic recovery and to help ensure that inflation, over time, is at levels consistent with its mandate, the Committee decided today to expand its holdings of securities.

The Planet Money staff gives you this:

So to give the economy a kick in the ass—and to pump up inflation a little bit—we decided to go on a shopping spree.

A bit more straightforward, no?  Try it out for yourself by clicking here.