New subject: [CTPP] Question about PUMS data and Geography

27 Mar 2009

Martin,

The 1% and 5% don't exactly refer to geography. They refer to the 
sampling fraction; the proportion of the total resondents who are 
included in the PUMS files.

PUMS geography is based on PUMAs (Public Use Microdata Sample areas) 
for the 5% files; these have to be at least 100,000 population.  The 
1% file uses super-PUMAs, which have to be at least 250,000 in 
population size. Your state data center should be able to tell you 
what the PUMAs are for your state or area; they're also included in 
the 2000 census PUMS documentation.

Hope this helps.

Patty Becker

At 03:37 PM 3/25/2009, you wrote:
...
 Hello,

I am looking to create some commute flow maps and I think I remember
someone mentioning (between all the please remove me from this list
e-mails) that flow maps can be created by using ACS data and the PUMS
geography.  I was at the Census site trying to download the PUMS
geography files and found that there were two types 1% and 5%.  Does
anyone know which geography file I should use?  The 1% or the 5%?
Thanks in advance,

Martin Catala
GIS Manager
CUTR

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Patricia C. (Patty) Becker         248/354-6520
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Re: [CTPP] Question about PUMS data and Geography