Sectoral Composition of Employment, Difference From National Average, 2007-to-2011 Average
The coefficient of specialization is calculated as the sum of the absolute differences in sectoral shares between a local area and the national average. The differences from the U.S. average were small in the three most populous counties (Maricopa, Pima and Pinal). In contrast, in several of the less populous counties, economic activity is heavily concentrated in a few sectors. Greenlee County — which is dominated by mining — had an industrial mix most different from the national average between 2007 and 2011.