IMO you're thinking about this all wrong.
Gold & silver are not commodities. They are not copper or iron ore or wheat.
It's not about supply and consumption.
It's about scarcity and characteristics.
It's not about what uses they have. It's all about this:
I'll spare you the 'goldbugs' bit about which is the oldest currency, currencies don't last, and all that.
All you really need to know is that gold (and silver) have and are used as currencies.
Then all you need to do is ponder which currencies will do best from now.
I'll give you a choice: US$, Euro, GBP, JPY, Aus$, NZ$, Gold, Silver.
If you know what the M3 growth is for the top 20 economies, and compare it with the growth in quantity of gold and silver, I think you'll get the right answer
Try these. I think the arguments for silver are similar to those for gold.
FUNDAMENTAL REASONS TO OWN GOLD
BY: JOHN EMBRY, CHIEF INVESTMENT STRATEGIST OF SPROTT ASSET MANAGEMENT INC. &
SPROTT GOLD AND PRECIOUS MINERALS FUND.
http://www.sprott.com/pdf/reasons_to_own_gold.pdf
This is a very long but very informative read about gold.
http://www.gata.org/files/RedburnPartnersG..._11-12-2007.pdf
Steve