By Michael Allan McCrae McKinsey tracked 2.8 per cent per annum increase in productivity between 2014 and 2016 mostly due to mines reducing headcounts and limiting spending, says the consultancy in a study published last month. Data is still pending, but McKinsey believes the productivity trend is continuing. McKinsey measures mine productivity using its MineLens Productivity Index, a measure of physical mining output, employment at the mine site, the value of assets at the site, and nonlabor costs.