urban v rural

Does anyone know how urban v rural is defined for a census tract ?  There is the "urban area" geography.  Are census tracts within an "urban area" defined as "urban?"  The definition of urban v rural may depend on the application.  For example the Centers for Disease Control has this distinction but I don't know if they use the US Census definition or something else.  Also is there a file with the fips codes for urban census tracts ? Dave Dorer

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  • Todd, can you provide any insight as to the differences between this slide deck and the 2020 urban/rural definition at https://www.census.gov/programs-surveys/geography/about/glossary.html#par_textimage_29 ?

    For the 2020 Census, the Census Bureau classified as urban all territory, population, and housing units located within densely developed Urban Areas of at least 2,500 people. The Census Bureau delineates Urban Area boundaries that represent densely developed territory, encompassing residential, commercial, and other nonresidential urban land uses. In general, this territory consists of areas of high population density and urban land use resulting in a representation of the “urban footprint.” Rural consists of all territory, population, and housing units located outside Urban Areas. For the 2010 Census and American Community Survey (ACS) data tabulations during the decade leading up to 2020, the Census Bureau identified two types of Urban Areas: urbanized areas of at least 50,000 people and urban clusters of at least 2,500 and less than 50,000 people. 

    This is the same as the 2010 UR classification.

    However, the slide deck you linked uses different criteria (slide 3):

    >= 425 dwelling units/sq. mi. (equivalent to > 0.66 units/acre)
    Or substantial impervious surface: >= 20%
    Or group quarters facility and >= 500 pop/square mile

    Moreover, the process for defining urban areas is substantially different (slide 4):

    1. Aggregating Urban blocks into Urban Areas:
    An initial contiguous core area with >= 500 dwelling units
    Contiguous Urban blocks
    2. Add-on nearby Urban blocks:
    Any number of “hops” <= 0.5 mile over land area
    And up to one “jump” of 0.51 – 1.5 miles over land area
    3. Check population: Urban Area must have >= 5,000 population

    It looks as though: A. the minimum population for an Urban Area has dropped from 50,000 in 2010 to only 5,000 in 2020; and B. Urban Clusters (2,500 to 50,000 population in 2010) are no longer a statistical entity for 2020. Can you confirm this? Who should I believe -- the Bureau's web page, or the slideshow you posted?


  • "Who should you believe?" GREAT question. 

    You should believe the Federal Register Notice published March 2022  https://www.federalregister.gov/documents/2022/03/24/2022-06180/urban-area-criteria-for-the-2020-census-final-criteria 

    It is remarkable that the census.gov page you pointed to has not been updated with current definitions. But the FRN has the force of a regulatory decision.

    Oh... your other question was about "urban clusters."  Census Bureau proposed and then decided that there was no meaningful distinction between an urban area and an urban cluster -- other than size -- so why call them different things? The two concepts were collapsed into the unified concept: urban areas. And the minimum qualifying population was set at (min.) 5,000. 

    PS:  I discuss, toward the end of my slideshow, there are some nuanced distinctions between Census UA's and FHWA UZA's. One big point: An urban area still must have 50,000+ population to qualify as the service area for a transportation-planning UZA.  (But that's a FHWA criterion, not Census criteria.) 

    --Todd Graham
      Metropolitan Council

    More PS: In my opinion... Census Bureau should be more like IPUMS = send you a "thanks" and a coffee mug when you find errors on the census.gov website.

  • Adding some clarification...

    This is not accurate:

    "A. the minimum population for an Urban Area has dropped from 50,000 in 2010 to only 5,000 in 2020"

    Nor is this:

    "there was no meaningful distinction between an urban area and an urban cluster"

    In both cases, it'd be more accurate if you replace "urban area" with "urbanized area." They're not the same thing. (I'd say that the ease which these terms can be confused is yet another good reason for doing away with one of them!)

    In the 2000 and 2010 definitions, urbanized areas and urban clusters are both types of urban areas. Urbanized areas have more than 50,000 residents and urban clusters have 2,500 to 49,999. As I understand, there will no longer be any such distinction. They'll all just be "urban areas".

    The previous minimum threshold for urban areas was 2,500. It's going up to 5,000 residents or 2,000 housing units.

  • This is not accurate:

    "A. the minimum population for an Urban Area has dropped from 50,000 in 2010 to only 5,000 in 2020"

    So, you are saying that the slide deck also contains inaccurate info? Great.

  • Yes, this bit in the slide deck:

    "Urban Area must have >= 5,000 population"

    Is contradicted by this in the FRN:

    "An area will qualify as urban if it contains at least 2,000 housing units or has a population of at least 5,000."

    As Todd said in his last message, the FRN is the official source, and there's a good summary of the criteria there.

  • And now I realize I confused things further by saying that using the term "urbanized area" in this statement would make it accurate:

    A. the minimum population for an Urban Area has dropped from 50,000 in 2010 to only 5,000 in 2020

    The 2010 minimum population threshold for urbanized areas had been 50,000. But that concept is going away entirely with 2020 definitions. The corrected statement is:

    A. the minimum threshold for an Urban Area has increased from 2,500 population in 2010 to either 5,000 population or 2,000 housing units in 2020

  • Hooo boy. Drama.

    The slideshow I shared -- this https://docs.google.com/presentation/d/1nSuDMXaVSva7vBEeZUfiS40apWHOqr4J/edit?usp=sharing&ouid=100562141110200427638&rtpof=true&sd=true  -- is my attempt to summarize a 9,000 words FR Notice into 6 slides. It's a communication vehicle for explaining the whole thing to planners who do not want (or need) to read 9,000 words. 

    At this time I'm not aware of anything egregiously "wrong" in the slideshow. I did -- I confess -- take some liberties in turning the 9,000 words into 6 slides. Like Jonathan says: the new minimum for an Urban Area is >= 5,000 population OR >= 2,000 housing units. I left out that part to keep things simple for my audience.

    I also glossed over or totally skipped nuances like... the crucial difference between a "Core Eligible Block Aggregation" and "Other [non-Core] EBAs."  Certainly the geographers at USCB need to understand these differences; Transpo planners? not so much.

    If there are true errors in the slideshow, let me know here, or with an email, I'm happy to hear from you.

    And again, the FR Notice is available https://www.federalregister.gov/documents/2022/03/24/2022-06180/urban-area-criteria-for-the-2020-census-final-criteria for anyone wanting the long read.


    Todd Graham