In the 1990s labour productivity in mining grew faster in Canada than in the United States, but from 2000 to 2006 labour productivity in mining continued to grow, albeit more slowly, in the United States, while it declined in Canada. [...] In fact, the increases in prices and employment share in mining, together with the high productivity level of the sub-sector, have resulted in a positive contribution to aggregate labour productivity growth over the 2000-2006 period, and to an offsetting effect on the post- 2000 aggregate labour productivity slowdown. [...] At all levels the first two digits always indicate the sector, the third digit the subsector, the fourth digit the industry group, and the fifth digit the industry. [...] The quality of mining output refers to factors such as ease of extraction, grade and purity of the deposit, and the size of the deposit. [...] Productivity Trends in Mining in the United States Due to the proximity of Canada and the United States many of the factors that influence mining productivity in the United States are also important in Canada.