Big gold and silver miners explore less and less. Please, look at the chart below:
After printing a top in 2012, exploration expenses have been going down sharply since then. In 2014 big miners spent $1,324 million on exploration, 40.4% less than in 2012. In the short term these lower costs should have a positive impact on the miners' cash flows (less spending = more cash). But in the medium and long term it will definitely have a negative effect on the miners mineral base. Simply put, if a gold miner does not search for gold now, it will have no gold to sell in the future.
This trend was still intact in the first quarter 2015 and, I guess, we will see similar developments in the coming quarters.
Here is the list of miners included in the above calculations: Barrick Gold, Agnico Eagle, AngloGold Ashanti, AuRico Gold, Yamana Gold, Coeur Mining, Eldorado Gold, Fresnillo, Gold Corp, Hecla Mining, Harmony, Hochschild, IAM Gold, Kinross, Newmont Mining, PanAmerican Silver, Silver Standard Resources.