Metro and the definition of "central city"

METRO indicates whether a household was located in a metropolitan area. For households within metropolitan areas, METRO specifies whether the housing unit was inside or outside the central city of the metropolitan area.

Is the central city a precisely defined concept? Does the central city refer to the city that is the “substantial population nucleus” of the metropolitan area? Or is it some smaller, denser region?

For a “substantial population nucleus” that consists of two cities (looking at you, Twin Cities), do residents of both get METRO = 2? What about residents of Bloomington (METAREA = 5121)?

Thanks in advance!

The designations of “central city” are consistent in concept over time, but the geographic boundaries do change from sample to sample. Addressing the specific example of the Twin Cities: There are three “central cities” that make up the Minneapolis-Saint Paul-Bloomington metropolitan area. The observations of METRO==5121 can have either METRO==2 or METRO==3. If they have METRO==2, they reside in one of the three central cities (Minneapolis, Saint Paul, or Bloomington). If not, then they do not live in one of the three central cities, but do live within the metropolitan area.

Thanks for the reply. I didn’t realize that a metro could have multiple central cities. What is the best resource for understanding what are the central cities for each metropolitan area?

In order to understand which cities correspond to which metropolitan areas, I’d consult the codes tab of the METAREA variable. For example METAREA==1521 “Minneapolist-St. Paul-Bloomington” notes which cities make up this metropolitan area. Additionally, you could reference this Census Bureau documentation.

I see, I didn’t realize those names were the central cities. Thanks!