I used Dun & Bradstreet 1990 employment data for the Houston region from 1996-1998 for
my dissertation, "Firm Location and Agglomeration in Discrete Urban Space: An
Empirical Study of the Spatial Distribution of Firms in the Houston Area". I had to
clean up problems, such as branch vs. headquarter, company with the same name but
difference SIC at different locations (such as Shell Oil), then the address accuracy, when
it comes down to geocoding. I listed problems with prefix and suffix confusions, Mixed
expressions of Rd., Road, Dr., St., Blvd., etc. Sequential inconsistency, spelling
inconsistency, and disordering of street numbers. Finally, there were quite some records
with P.O. Box numbers. There were no way those P.O. Boxed records could be geocoded.
Since 1998, I had worked for the Forecast Group at HGAC from 1998 to 2002. We used InfoUSA
(then ABI) for the base year employment input for the travel forecast model. I cleaned
InfoUSA data, 1995, 1999, and 2001, for our region. Info USA had similar problems
mentioned earlier as in the Dun & Bradstreet. However, there were major differences in
the source data collections. Dun & Brad collected data through credit reports,
unemployment insurance records, and other administrative records. On the other hand,
InfoUSA collected data through phone books and calling to obtain employment counts. Since
2002, I have been working in the Travel Forecast model group that I didn't actually
cleaning the data anymore. However, I still closed worked with the Forecast group for
regular updates of the employment data. I compared Info USA data for years, 2003, 2004,
2007, 2008, etc., There are still problems with this group of data. For examples, it often
missed larger employers or the number of count are not accurate. From time to time, I
contact local larger employers such as hospitals, government, schools, etc., to verify
employment counts. Another effective ways to verify employment is to make use of the web,
especially the fact sheet, to supplemental our employment count.
Hope it helps.
Sharon Ju, Ph.D.
Sr. Transportation Analyst
3555 Timmons Lane
Houston, TX 77027
From: ctpp-news-bounces(a)chrispy.net [mailto:firstname.lastname@example.org] On Behalf Of
Reardon , Tim
Sent: Tuesday, June 28, 2011 2:15 PM
Subject: [CTPP] Proprietary Employer Data -- Comments on the various providers?
I have managed to assemble some funding to acquire employer data for our 164-municipality
transportation modeling region in Eastern MA, and I am wondering if any of you have
comments on the accuracy and utility of the various proprietary employer data sources
currently available. I have been in conversations with two major providers (InfoGroup and
Dun & Bradstreet) and have received sample files for certain zip codes, but it is hard
to assess the accuracy or completeness of either sample.
I'm wondering if anybody can offer insight on working with such data, and whether you
have suggestions on choosing a vendor. We will be using it primarily to determine
employment by sector at very fine geographies (250m or 1km grid cells) for land use
planning and analysis. Some concerns we have already identified include: branch vs.
headquarters employment, public sector employment, "paper companies" and
verification, and the accuracy of the goecoded location that accompanies each record.
Any thoughts are appreciated. Feel free to reply off-list if concerned about publicly
trumpeting or bashing somebody's product.
Timothy G. Reardon -- Senior Regional Planner
Metropolitan Area Planning Council
60 Temple Place | Boston, MA 02111
Say it with a map! Find data and bring it alive at www.MetroBostonDataCommon.org
Please be advised that the Massachusetts Secretary of State considers e-mail to be a
public record, and therefore subject to the Massachusetts Public Records Law, M.G.L. c. 66