The methodology for the 2011 rankings largely corresponds to that used last year, which emphasizes the robustness of a region's growth both recently and over time. It allows the rankings to include all of the metropolitan statistical areas (MSAs) for which the Bureau of Labor Statistics reports monthly employment data. They are derived from three-month rolling averages of U.S. Bureau of Labor Statistics "state and area" unadjusted employment data reported from November 1999 to January 2011.
"Large" areas include those with a current nonfarm employment base of at least 450,000 jobs. "Midsize" areas range from 150,000 to 450,000 jobs. "Small" areas have as many as 150,000 jobs. This year’s rankings reflect the current size of each MSA’s employment, unlike last year when some were “held over” in size categories to facilitate comparisons.
This year's rankings use four measures of growth to rank all areas for which full data sets were available from the past 10 years. Because of the expanded availability of data since last year, we were able to include another small MSA (Manhattan, KS) in this year’s rankings for a total of 398 regions. Generally, this year's rankings can be directly compared to the 2010 rankings for MSAs for the large and midsize categories, although there are eight MSAs that are reported in the Small size category that were Medium last year and one (Honolulu, HI) that was large that is now reported as medium-sized. In instances where the analysis refers to changes in ranking order, these adjustments are made accordingly, reporting the changes in ranking as if they had been categorized in their current category last year.
The index is calculated from a normalized, weighted summary of: 1) recent growth trend: the current and prior year's employment growth rates, with the current year emphasized (two points); 2) mid-term growth: the average annual 2005-2010 growth rate (two points); 3) long-term trend and momentum: the sum of the 2005-2010 and 1999-2004 employment growth rates multiplied by the ratio of the 1999-2004 growth rate over the 2005-2010 growth rate (two points); and 4) current year growth (one point).
The data reflect the North American Industry Classification System categories, including total nonfarm employment, manufacturing, financial services, business and professional services, educational and health services, information, retail and wholesale trade, transportation and utilities, leisure and hospitality, and government.