The latest balance sheet of the Federal Reserve makes me wonder whether it's solvent. That's because its balance sheet has clearly deteriorated in the last year. And with $40 billion in capital, that deterioration could take a big bite out of the Fed's capital.

Unfortunately, I do not know enough about how the Fed gets its capital or how it accounts for the value of its assets and liabilities to be able to do more than raise questions. But here are three things that concern me:

• Declining asset quality. The total value of the U.S. Treasury securities on the Fed's balance sheet declined by $312 billion between July 2007 and this July -- a 43% drop in this highest quality asset.
• Increase in shakier assets. During this same period, the balance in Term Auction Facilities -- the credit line that investment banks are using to get their shakier assets -- such as Collateralized Debt Obligations (CDOs) off their balance sheets --increased from $0 to $150 billion. Another $29 billion in assets come from Maiden Lane, LLC -- the entity created for the Fed to take on the toxic waste that sank Bear Stearns.
• High leverage. While the Fed has more capital backing up its assets than the typical investment bank -- which holds $1 of capital for every $32 in assets -- the Fed is still highly leveraged -- with only $1 of capital for every $23 of assets -- it borrows the rest. Put another way, if the Fed was forced to account for its balance sheet on a mark-to-market basis, a mere 4.5% decline in the value of the Fed's assets would wipe out its capital.

These observations raise questions in my mind: