To: ctpp-news@chrispy.net
From: Patty Becker <pbecker@umich.edu>
Sent by: ctpp-news-bounces@chrispy.net
Date: 03/27/2009 08:00AM
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
_______________________________________________
ctpp-news mailing list
ctpp-news@chrispy.net
http://www.chrispy.net/mailman/listinfo/ctpp-news-------------------------------------------------------------------------------------------------
Patricia C. (Patty) Becker248/354-6520
APB Associates/SEMCCFAX 248/354-6645
28300 Franklin RoadHome 248/355-2428
Southfield, MI 48034 pbecker@umich.edu _______________________________________________
ctpp-news mailing list
ctpp-news@chrispy.net
http://www.chrispy.net/mailman/listinfo/ctpp-news