This year's rankings continue the methodology used last year, which emphasizes the robustness of a region's growth and allows the rankings to include all of the metropolitan statistical areas 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 1998 to January 2009.
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.
"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. One community in last year's top small MSA group grew enough that they are now considered a midsize MSA: Charleston, WV.
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 -- 336 regions in total. The Bureau of Labor Statistics, however, no longer reports employment detail for MSAs with employment levels less than 30,000 in its monthly models, resulting in shifts as MSAs were dropped. As a result, this year's rankings can be directly compared to the 2008 rankings for MSAs for the large and midsize categories, but there are some adjustments needed for year-to-year comparisons in small MSA category. In instances where the analysis refers to changes in ranking order, these adjustments have been taken into account.
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 2003-2008 growth rate (two points); 3) long-term trend: the sum of the 2003-2008 and 1998-2002 employment growth rates multiplied by the ratio of the 1998-2002 growth rate over the 2003-2008 growth rate (two points); and 4) current year growth (one point).