Mining yields depend primarily on the quantity and accessibility of reserves, neither of which can be enhanced by capital investments. The discovery of new mine

Mining yields depend primarily on the quantity and accessibility of reserves, neither of which can be enhanced by capital investments. The discovery of new mines has caused significant fluctuations in prices, see for example http://www.straightdope.com/columns/read/611/what-happened-to-all-the-gold-spain-got-from-the-new-world http://www.straightdope.com/columns/read/611/what-happened-t...