I want to thank everyone for their input and assistance.  A great education for me.

 

After several e-mails it became apparent that what I really needed was the LEHD data…Again thanks for all you input…very HELPFUL!

 

 

From: ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Patty Becker
Sent: Friday, March 27, 2009 11:00 AM
To: ctpp-news@chrispy.net
Subject: Re: [CTPP] Question about PUMS data and Geography

 

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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