Lower interest rates stimulate economic activity by lowering the cost of borrowing, making it easier for consumers and businesses to buy and build. Higher interest rates slow the economy by increasing the cost of borrowing. (See monetary policy for a fuller explanation.)
The Federal Reserve usually adjusts the federal funds rate by 0.25 or 0.50 percentage points at a time. From early 2001 to mid 2003 the Federal Reserve lowered its interest rates 13 times, from 6.25 to 1.00 percent, to fight recession. In November 2002, rates were cut to 1.75, and many interest rates went below the inflation rate. (This is known as a negative real interest rate, because money paid back from a loan with an interest rate less than inflation has lower purchasing power than it had before the loan.) On June 25, 2003, the federal funds rate was lowered to 1.00 percent, its lowest nominal rate since July, 1958, when the overnight rate averaged 0.68 percent. Starting at the end of June, 2004, the Federal Reserve started to raise the target interest rate. As of December 2005, the rate is at 4.50 percent; this is the result of fourteen 0.25 percent increases.
http://en.wikipedia.org/wiki/Federal_Reserve
