Group quarter population - large discrepancy between ACS 5-year and Decennial estimates

I am working on building a synthetic population that includes group quarters and am stumped by a pretty large inconsistency between the ACS 5-year and decennial census reported group quarter populations in the block group that contains the Cook County Jail in Chicago (block group 170318435001). The ACS 5-year estimates for the group quarter population in this block group hover around 9k in 2019, 2020, 2021, and 2022. However, the decennial 2020 estimate is only around 5k. The current Cook County Jail population is listed around 6k (https://www.cookcountysheriffil.gov/wp-content/uploads/2024/03/CCSO_BIU_CommunicationsCCDOC_v1_2024_03_08.pdf).

Wondering if anyone has any idea why this discrepancy could be so large? I am looking at table B09019 for ACS and the 2020 Census Redistricting Data (P.L. 94-171) Summary Files (P5) (https://www.census.gov/programs-surveys/decennial-census/about/rdo/summary-files.html#P1). 

Appreciate any input! 

Parents
  • I have worked with the group quarters population and the group quarter facilities counts in several different situations.  West Feliciana LA (a Parish) Houses the Angola Prison, one of the largest maximum security priosns in the US.  In 2010 the blocks encompassing it reported about 5500 individuals of which about 75% were black, in 2020 the report showed that 15% were black and the rest had become white.  The Bureau refused to say how this occurred.  The numbers from the ACS mirror the 2010 Census.  DP could be a factor, but no one is saying.  For DP they left invariant the number of housing units and GQ facilities.  They eventually published a file by block that gave the facility type for GQ by block along with the housing units.  This is not officially a part of the redistricting file, though it should be.  For DP they required at least one resident in every GQ facility.  As youmust know they severed the relationship between housing units and GQ and population.  Put another way, all of the occupans are made up.  This has lead to Occupied Units with no People,, and people with no units.  See https://www.nytimes.com/2022/04/21/us/census-data-privacy-concerns.html   

    The 2020 Census Suggests That People Live Underwater. There’s a Reason.

    Technology advances forced the Census Bureau to use sweeping measures to ensure privacy for respondents. The ensuing debate goes to the heart of what a census is.

    Garbage In, Garbage Out.  Use the ACS!!!!

Reply
  • I have worked with the group quarters population and the group quarter facilities counts in several different situations.  West Feliciana LA (a Parish) Houses the Angola Prison, one of the largest maximum security priosns in the US.  In 2010 the blocks encompassing it reported about 5500 individuals of which about 75% were black, in 2020 the report showed that 15% were black and the rest had become white.  The Bureau refused to say how this occurred.  The numbers from the ACS mirror the 2010 Census.  DP could be a factor, but no one is saying.  For DP they left invariant the number of housing units and GQ facilities.  They eventually published a file by block that gave the facility type for GQ by block along with the housing units.  This is not officially a part of the redistricting file, though it should be.  For DP they required at least one resident in every GQ facility.  As youmust know they severed the relationship between housing units and GQ and population.  Put another way, all of the occupans are made up.  This has lead to Occupied Units with no People,, and people with no units.  See https://www.nytimes.com/2022/04/21/us/census-data-privacy-concerns.html   

    The 2020 Census Suggests That People Live Underwater. There’s a Reason.

    Technology advances forced the Census Bureau to use sweeping measures to ensure privacy for respondents. The ensuing debate goes to the heart of what a census is.

    Garbage In, Garbage Out.  Use the ACS!!!!

Children