A recent poll of major BHP and Rio Tinto shareholders by investment bank UBS showed revealed that the owners' No. 1 concern by an overwhelming margin was the direction of iron ore prices.

But it took just 6¢ to reveal that there are ever-more material worries for our pair of dual-listed global miners than the day-to-day price of any particular commodity and to offer timely, if unwelcome, reinforcement of the commercial logic at the root of big mining’s intensifying effort to embed “social value” into the matrix of its decision making.