PUMA populations, 100,000 or 65,000?

100,000 is correct. In some documentation, it's also mentioned that they also all meet the 65K threshold, which is relevant since this means you can get 1-year estimates for all PUMAs in the nation.

Perhaps the confusion is around the 65,000 limit as one of the criteria for inclusion for the one-year ACS.

Thank you Jnigrine for responding.  Yes, confusion.  I see in the 1yr ACS that the small counties are left out of the tables (but included in the 5yr).  I'm still unsure when the 100,000 threshold is used and when the 65,000 is used.    

Thank you, Mark for taking the time to respond.  If PUMAs have at least 100,000 people then the 65,000 threshold is irrelevant... I'm still missing something

PUMAs are created to have at least 100,000 people -- sometimes much more.

The smallest PUMA is Elkhart County (Outside Elkhart City)--Goshen City, Indiana, with100,044. The largest is NYC-Queens Community District 7--Flushing, Murray Hill, & Whitestone, New York, with 270,930

Ignore the 65,000 threshold. That is for ACS 1-year reporting, not for PUMA definitions.

Thanks Glenn, I get the 1000,000 is for PUMAs.  I use the ACS data (PUMS) all of the time.  How does the 65,000 play into that.  If everything is at least 100,000 then when would there be anything smaller?

Hi - The 65,000 does not play into PUMS; it relates only to tables. PUMS' smallest units are PUMAs.

I think I got it!

The 65,000 threshold is for the tables.  They include only areas with >= 65,000, otherwise the area is not listed

The 100,000 threshold is for PUMAs.  These come into play while using the PUMS data

It doesn't play into anything. The 65,000 is not relevant to PUMAs. It's for the ACS. Two different things.

BTW-As we are talking about PUMAs being an ACS tabulation geography, is anyone using them that way? When ACS was coming together I remember sitting in meetings talking about the value of getting PUMA level annual ACS every year. Fast forward, are people using the PUMA level annual ACS data? From the transportation perspective we were always hopeful that someday we could get workers at their workplace level PUMA data added in. We talked about it and worked on it since 2000. We came close in our last special tab with POW PUMAs (2012 to 2016) but the idea of filling in those Workers at their Workplace tables seem to have gone the way of the dodo bird ;-(   

I was getting confused between the tables and the PUMs data (I download the data and use SAS to analyze).  When I use the tables (poverty and population) I see counties, not PUMAs. When I use the PUMA data, I see PUMAs and convert to county groupings.  

PUMAs are not "county groupings" -- a PUMA may comprise fractions of counties.

PUMAs appear in both the ACS PUMS and the ACS summary tables.

ACS summary tables are provided for many different summary levels: counties, census tracts, ZIP Code Tabulation Areas, and many others, including PUMAs.

Every PUMA must include 100,000 residents (in the year of its reference census, e.g., each PUMA in the 2020 PUMA definitions included at least 100,000 residents according to the 2020 census).

ACS 1-year summary tables cover only areas that include at 65,000 residents. That includes all states, many but not all counties, and all PUMAs.

ACS 5-year summary tables cover all areas in each summary level covered by a given table.

PUMAs are the only sub-state areas identified in PUMS. PUMAs have a many-to-many relationship to counties. I.e., it may be possible to crosswalk from a single PUMA to a single county, or from multiple PUMAs to a single county, or from a single PUMA to multiple counties; it varies. But counties are not directly identified in the PUMS when accessed directly from the Census website.

If you get ACS microdata via IPUMS USA, then you can also get identifiers for counties, cities, or metro areas where it's possible to identify them based on the identified PUMAs (accepting a small degree of mismatch between the PUMA extents and the city or metro areas).

True, I combine them to get to counties/combined counties.  There are some largely populated counties with many PUMAs and there are some PUMAs that cover more than a county, so I have to group them.  It's the best I can do at this point.  

Thanks Jonathan

Your paragraph

"PUMAs are the only sub-state areas identified in PUMS. PUMAs have a many-to-many relationship to counties. I.e., it may be possible to crosswalk from a single PUMA to a single county, or from multiple PUMAs to a single county, or from a single PUMA to multiple counties; it varies. But counties are not directly identified in the PUMS when accessed directly from the Census website."

states it very well!!

I will take another look at IPUMS.  Thank you for the information