Article from the economist I read years ago basically said something like this...The price of Gold is based on the biggest consumer, which is India. They typically would give multiple sets of gold jewelry as a dowry...but now, they don't give as much because people aren't as well off financially, so they typically give a single set. This impacted the price.
Heard some cool shit on a 2 hour history channel special on Fort Knox though - that place is either brimming with gold (more than all the developed nations combined), or there isn't shit in there and we're all being lied to. Cool thing it said, if you ever got into the vaults, the place locks down and fills with water, drowning anyone inside (the french vaults were built with this).