A few years ago, I read a balance sheet that stated coins were an asset to the Federal Reserve Board, and paper currency was a liability. I am no economist, and the people that I know who do accounting ignored my request for information on the matter. My best guess is they did not have a comprehensive understanding.
I have purchased a good share of coins from the United States Mint, however do so anchored in the information that it may be a prudent investment, not for my generation, but for my grandchildren in 7 generations.
It seems like this is a loaded question full of fractional reserve policy and metal prices. Still though, I believe I can grasp this information if someone could point me in the right direction.