Since its creation in 1913, the primary intended role of the U.S. Federal Reserve Bank has been that of protector. In theory, the central bank was bestowed with the power to shape monetary policy in a way that would keep both booms and busts in check. The two main tools at its disposal -- interest rates and money creation -- would provide a "ceiling of normalcy" above expansions AND a "net of safety" below contractions.
What Most People Don't Realize About The Fed's Superpowers
"The primary basis for today's belief in perpetual prosperity and inflation with an occasional recession is what I call the 'Potent Directors Fallacy.' It is nearly impossible to find a treatise on macroeconomics today that does not assert or assume that the Federal Reserve Board has learned to control both our money and our economy. Many believe that it also possesses the immense power to manipulate the stock market. The very idea that it can do these things is false."