In McCauley Post Voxeu (first of the three), it presents a pictorial representation or an exorbitant privilege:
As McCauley points out:
Although the US Treasury reduction did not drag the credit ratings of the US states, drew the credit grades of the companies sponsored by the United States government that subscribe mortgages in the United States home. On May 19, Moody’s continued his reduction in the US Treasury with a reduction of his housing rooms, Fannie and Freddie, as well as federal mortgage loans (those lenders or penultimate recurring to US banks).