Australian mining has “precious few with legitimate claims to improving core productivity", according to a global study of industry production published by accounting firm PwC Australia.

For good measure, in a set of conclusions that will surely have BlackRock’s Evy Hambro whispering “I told you so", PwC reckons that, globally, the mining sector’s productivity has been sinking since 2008, when the industry began trying to ramp up output in response to boom-time price signals.