I think it has been suggested (can't remember where) that a rising gold price will lead to falling mine production. Gold in the ground is an asset to the miners and who sells an asset when it's rising in value (particularly when they just get paid in devaluing paper)? They also need to sell fewer ounces to cover their costs as the price rises. Counterintuitive but there is some logic there I think.

The smart thing to do is to mine the gold, sell what you need to cover your costs (hence pay no taxes), and leave the rest as inventory, make it into bars and ship it to a secure vault in Switzerland for the ultimate benefit of shareholders.