From staff of AEA Committee on Economic Statistics:
This is BEA's first official release of GDP by county statistics for 2001–2018 for all counties in the United States. The GDP by county statistics incorporate new and additional source data and methodology improvements to the December 2018 prototype GDP by county statistics. This release also expands the industry detail. The new GDP by county statistics along with BEA's county estimates of personal income offer a more complete picture of local area economic conditions.
The release of GDP by county statistics replaces the release of GDP by metropolitan area statistics, previously occurring each September. GDP by metropolitan area statistics will now be made available with the release of GDP by county statistics.
Additional information on the GDP by county statistics, including a brief overview of the estimating methodology and data sources, is available. Additional in-depth information on the methodology will be available in the February 2020 issue of the Survey of Current Business.
In addition to industry contributions to GDP, the data includes current-dollar GDP; inflation-adjusted or real GDP; percent change from the preceding year; and quantity indexes.
Like county personal income data, the new GDP statistics covers 3,113 areas, including county equivalents such as Louisiana's parishes and Alaska's boroughs, the District of Columbia, and the independent cities in Maryland, Missouri, Nevada, and Virginia. Kalawao County, Hawaii, and the smaller independent cities of Virginia are combined with adjacent counties.
GDP statistics are based on the place of production, such as the county where an office or factory is located, regardless of where the workers live. This differs from BEA’s personal income statistics, which measure the incomes of all people residing in a county, no matter where they work.