“…Similar questions dealing with the threat of physical depletion and the availability of resources for the future have been recurrently addressed in many studies (e.g. Govett and Govett, 1972;Skinner, 1976;Cook, 1976;Tilton, 2003Tilton, , 2006Yaksic and Tilton, 2009;Rosenau-Tornow et al, 2009;Gunn, 2011;Shodde, 2010aShodde, , 2017cCrowson, 2011;Prior et al, 2012;Henckens et al, 2009;Sverdrup and Ragnasdóttir, 2014;Calvo et al, 2016;Northey et al, 2018;Tilton et al, 2018). However, despite the simple and convincing logic behind the "fixed stock paradigm" (strongly influenced by the Malthusian perspective), the main causes that determine mineral production are related to externalities and other factors directly or indirectly involved in the "opportunity cost paradigm" .…”