Dan,

We, too, use InfoUSA, and I have found that if you have a dataset that includes both the “individual” and “firm” records for a hospital, for example, you can get rid of the duplication by deleting the “individual” records. If you’re like us, you need both types in the dataset so that you don’t lose some of your small business owners like chiropractors, dentists, and the like not associated with a hospital.

As far as the geocoding, we have some businesses plotted 6 miles from their physical location. I think this will improve as Infogroup moves to geocoding to the parcel instead of the address range. But for the time being, there’s lots of clean-up. I think that will be the case with data from any source.

PH: 608.785.6141

Tim,

We have used InfoUSA the last few years. It  looks very similar to the InfoGroup product.  You’ve mentioned the problems we also have run into with InfoUSA.

There is double counting in the public sector (an employee counted under a department also counted under the agency total).  There were a few branch vs. headquarter issues, but it was actually in pretty good shape.

We culled through the largest employers looking for suspicious employee totals and duplicate employers. The result was the total employment being reduced by 4.5%, but we still think it is about 10% too high.

I am unsure on the source InfoUSA used for geocoding addresses (never did get a clear answer from InfoUSA on that) but it was significantly different than our GIS base mapping in a few areas.  So, some manual clean up was needed to move employers to the correct side of a street.

Also, about 3% of the employers were geocoded to a ZIP code centroid (these included PO boxes and other addresses InfoUSA was unable to geocode). We were able to geocode  about half of these.

I’m also interested in hearing from others experiences with  these proprietary data sets.  Thanks.

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. 

Thanks,

Tim Reardon

___________________________________________

Timothy G. Reardon -- Senior Regional Planner

Metropolitan Area Planning Council

60 Temple Place | Boston, MA 02111

617-451-2770 x2011

treardon@mapc.org

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 § 10.