8 Mar
2013
8 Mar
'13
1:49 p.m.
Thanks, Ed.
I have been working LEHD data for 2 weeks and comparing it with other
sources (REMI, Claritas, WP, etc). All sources has different number
for 2010, for example, which one is the good one ? LEHD has all jobs,
primary jobs, private jobs, etc. I found the use primary job data give
close number with other sources, am I on the right track ?
I have not compared LEHD data with 'just released' commuting data set,
I guess it would be the same and LEHD has better resolution. What do
you think ?
Thanks,
Hary
On Fri, Mar 8, 2013 at 10:22 AM, Ed Christopher <edc(a)berwyned.com> wrote:
A few of us have been getting calls and emails from
people who have been
looking at the commuter follow data the Census Bureau just released, the
On the Map (LEHD) and some of the earlier flow data. If you have, you
probably noticed some interesting (or maybe wierd) things. Needless to
say a good understanding of the data is needed to sort out some of the
issues. Below are some references and points that may be of interest.
What are people noticing with the data?
---------------
In the January 20011 Status Report newsletter there is an article from
the NY State DOT by the late Nathan Erlbaum which discusses the issues
surrounding the various flow data sets. The article “Commutation Flow:
CTPP 2000, ACS and CTPP, and LEHD-OTM” can be found at
http://www.trbcensus.com/newsltr/sr0111.pdf (starting on page 6). In it
is a link to a larger body of work that Nathan did on the topic. a read
of this is must if you are having questions about the data.
Regarding the LEHD and CTPP flow data, there is an NCHRP report that has
been completed that is also worth reviewing. It gets into detail about
some of the differences between the two data sets. It can be found at
http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP08-36%2898%29_FR.pdf
Elaine Murakami reminds me that
1. LEHD does not include self-employed (approx. 10%)
2. LEHD only recently included federal workers, but does not include
MILITARY
3. LEHD is jobs and ACS is "workers at work".
Periodically issue like this pop up and there is a discussion on the
list serve. there is an archive but off course it takes some time to
mine and search through. If anyone is interested in looking through it,
it is open to the public and available at
http://www.chrispy.net/pipermail/ctpp-news/. There was a discussion
around august of 2010 dealing with flow data but it centered more on
availability.
Hope this helps.
--
Ed Christopher
708-283-3534 (V)
708-574-8131 (cell)
FHWA RC-TST-PLN
4749 Lincoln Mall Drive, Suite 600
Matteson, IL 60443
_______________________________________________
ctpp-news mailing list
ctpp-news(a)ryoko.chrispy.net
http://ryoko.chrispy.net/mailman/listinfo/ctpp-news