I saw this passage in the WSJ today.
"But some worrying disparities have emerged between what commercial banks get for their deposits with the Fed, 0.25%, and the effective federal-funds rate, 0.09%. In 2009, the gap averaged 0.09 percentage points.
A major reason for the gap: The Fed doesn’t pay Fannie Mae and Freddie Mac for their deposits, so the government mortgage companies are willing to take just a bit more than that from commercial banks to get a return on their cash."
http://online.wsj.com/article/SB10001424127887323980604579029242449050918.html
I am not following the 2nd part. How does Fannie and Freddie affect the gap between the federal funds rate, and the rate banks are paid for their deposits?