The Fraser Institute Annual Survey of Mining Companies was sent to approximately 3,800 exploration, development, and other mining-related companies around the world. Several mining associations also helped publicize the survey. (Please see the acknowledgements.) The survey was conducted from September 15 to November 27, 2015. The companies that participated in the survey reported exploration spending of US $2.2 billion in 2015 and US $2.5 billion in 2014.