Using IHS Polk datasets: FAQs
Car registration data comes from individual states, car manufacturers, finance companies, and other third-party sources. However, not all states and not all car manufacturers report the same level of information. All new registrations are recorded for all vehicles in all states, down to the ZIP Code level. However, some manufacturers and some states don't report dealer-level information. For example, while it's possible to know the number of BMWs sold in a particular New York ZIP Code, it's not possible to know which dealers sold them.
It's more difficult to collect used registrations, in part because selling a used car is often a private transaction. For those states who report used registrations , the information comes from the updated registration and title (a change in the last name and address associated with the original registration), or from those car manufacturers who run certified pre-owned programs.
In tables, you'll typically see columns for (or options for columns for) New Registrations (unfiltered) and New Registrations (%). Unfiltered registrations are all of the registrations for the area or time period you are looking at; in other words, all of the registrations, without any of the filters (dealer, zip, age, income, make, model, etc.) you are applying. The percentage reflects the filtered results.
Let's look at an example. Here we're examining registrations for Robinson Bros. Ford Lincoln in Baton Rouge, Louisiana.
|ZIP Code||New Registrations||New Registrations (unfiltered)||New Registrations (%)|
As we can see, there were no sales for this particular dealer in the 70052 ZIP Code, although there were a total of 44 car sales (any make) there. Therefore, Robinson Bros Ford Lincoln had zero percent market share of the new registrations in that ZIP Code. However, they did sell 22 of the 771 total cars in the 70737 ZIP Code, which accounted for 2.85% of all cars sold in that ZIP Code.
When people purchase cars, they don't always register them at the purchasing dealer. They may register them at a dealer closer to home. Therefore, Dealer DMA Name isn't always a true indication of where a car was sold; it reflects only where the car was actually registered.
For more information, see the question "If I want to see registrations on a map, should I use the dataset-based attributes like Dealer DMA Name or Dealer ZIP Code, or should I use the map-based attributes like DMA or ZIP Code?" in this FAQ.
To see the most accurate picture of registration data, use both; each one shows you a different aspect.
- A dataset-based attribute like Dealer DMA Name returns all registrations that are attributed to a dealer that is physically located within that DMA, even if the cars are not located there. That means that on a map, you will see registrations that are outside of the specified DMA.
- A map-based attribute like DMA returns only those registrations within the DMA itself; it is bound by the geography. Therefore, on a map, you will see only registrations within the specified DMA.
This applies to Dealer State vs. State, as well as Dealer ZIP Code vs. ZIP Code.
To help illustrate the point, let's look at an example. We have two target series configured: The first one looks at Buick registrations that are attributed to any dealer that is located in the Pittsburgh DMA, using the Dealer DMA Name attribute. The second series looks at Buick registrations that geographically confined to the Pittsburgh DMA, using the map-based DMA attribute.
Figure 20: Using two different target series to find Buick registrations in the Pittsburgh DMA
When we map each target series, it's easy to see how differently the dataset-based DMA Dealer Name attribute and the map-based DMA attribute affect the registration data that's returned. Because the map-based DMA attribute excludes any registrations for cars that fall outside of the specified DMA, it doesn't account for cars purchased by anyone outside of the DMA (individuals or other dealers).
On the other hand, using the DMA Dealer Name attribute does show all of the cars purchased from dealers within the DMA, regardless of where the actual registration occurred (commonly called "pump out").
Figure 21: The difference in map results when using the Dealer DMA Name dataset-based attribute vs the DMA map-based attribute
You can download a spreadsheet with information on Polk segments. This information was made available by IHS Polk and is current as of this writing.
If you don't see your question answered in this topic, check with Rhiza support or with your IHS Polk representative.
© 2016, Rhiza, Inc. All rights reserved. Last updated February 16, 2017 01:21:16 PM.