The best-known aspect of this epic spending spree is the U.S. Treasury's $700 billion Troubled Assets Relief Program, whose remit has included purchasing so-called toxic securities, giving banks cash and helping Detroit automakers avoid bankruptcy.
The Treasury also gave $300 billion in guarantees for struggling Citigroup, poured $200 billion into Fannie Mae and Freddie Mac, and granted an additional $50 billion in temporary guarantees to keep investors from pulling out of money market funds.
The Federal Reserve has also been busy. Central bankers have said they could purchase as much as $1.3 trillion of commercial paper from nonfinancial companies to make sure businesses have the working capital they need in an environment where banks are hesitant to lend. The Fed has committed an additional $1 trillion to a variety of credit facilities designed to encourage banks to loosen up.
Among other federal rescue measures we have the Federal Deposit Insurance Corp.'s decision to guarantee as much as $1.4 trillion in interbank loans, $300 billion for the Federal Housing Administration to insure mortgages in danger of foreclosure and a $150 billion aid package for insurance giant AIG.
The federal government is on the hook for $5 trillion of debt that Fannie Mae and Freddie Mac underwrote. The two companies themselves hold only a third of that debt, so it's unclear what the taxpayer's ultimate liability will be there.