بهره وری نیروی کار، هزینه ها و بقای معدن در طول رکود اقتصادی

The US copper industry over the 1975–90 period provides empirical support for this expectation. But surprisingly, it also suggests that mine survival depends (a) more on labor productivity than variable costs, and (b) more on the ability of a mine to increase its labor productivity once in a recession than on a high level of labor productivity at the start of a recession. An important factor affecting the extent to which mines increase labor productivity once in a recession is the life expectancy of their reserves.