Looking at sheer job numbers can help us understand a lot about the economy of the country or other geographic area of interest. However, as a Brookings Institution Report released earlier this year pointed out, we can also learn a lot (maybe even more) by looking at job density — the number of jobs per geographic area of interest (think acre, square mile, etc.) — and how that’s changed over time. Brookings’ report, which analyzed data from 2004 to 2015, found that job growth during that time favored already job-dense locations in metro areas.

For the series of maps below, we performed our own analysis of U.S. Census LODES (LEHD Origin-Destination Employment Statistics) data to determine job density change from 2013-2017 at the Census tract level across the country. First, we calculated density according to the number of jobs per square mile of Census tract, then subtracted the 2013 density from the 2017 density so that the maps symbolize the change between the years.

The map below takes a look at nationwide job density change and shows a similar outcome to what researchers at Brookings found: Job density is increasing at the greatest rates in the places where it was already pretty dense. The data for New York State tell an interesting story in and of themselves. The Census tract with the country’s greatest density loss is in Kings County, New York, and the Census tract with the country’s greatest density gain is in New York County.

Source: Census Bureau (Workplace Area Characteristics, LODES Data) with analysis by the Atlanta Regional Commission; note: there was no data for South Dakota in 2017.

The interactive map below shows the job density change in Georgia at the census tract level. Even in the state, we can see how job density favors particular areas, sometimes even within the same county. Statewide, Fulton County has both the top three Census tracts for job density gains and the top two tracts for job density losses.

Source: Census Bureau (Workplace Area Characteristics, LODES Data) with analysis by the Atlanta Regional Commission.