How does Business Analyst apportion things like Median Age and Income?

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03-24-2020 11:58 AM
RobertFord
New Contributor III

The title says it all. I am wondering what the methodology is behind ESRI Business Analyst apportioning things that aren't counts.

I've read and understand the documentation on apportionment (Data apportionment—ArcGIS REST API: GeoEnrichment Service | ArcGIS for Developers ) but it does not mention statistics such as average, median,...etc.

Thanks!

3 Replies
Jason_RobinsonRobinson
Esri Regular Contributor

Robert,

It sounds like you more interested in understanding how calculated variables like average/median are handled in spatial apportionment for custom polygons.

The below documentation link is for ArcGIS Business Analyst Desktop software, which has three different spatial apportionment methods that can be toggled and the ability to modify each, however it should provide some additional information when as the default apportionment for both local software and geoenrichment is hybrid.

Data tab—Help | ArcGIS for Desktop 

For calculated variable the information can be found for the data itself at https://downloads.esri.com/esri_content_doc/dbl/us/J10268_Methodology_Statement_2019-2024_Esri_US_De... 

I will check with the data team to see if there is a little more direct details in how calculated variables, like medians and averages, are handled with spatial apportionment which is ultimately point in polygon type calculations (census block centroids for the most accurate level).

Regards,

Jason R.

RobertFord
New Contributor III

Thank you Jason! This helps me understand some other things but yeah I am ultimately interested in performing apportionment of median age and income to custom polygons using non BA tools. I've played with finding medians using bins (age groups and income brackets), but am still a little confused.

Thank you again!

Jason_RobinsonRobinson
Esri Regular Contributor

Robert,

The Esri Data team put together a detailed example of Average Home Value as a simple example as median functions that estimate the medians based on the values for the Income ranges and their ranges and Excel does not support Medians using linear interpolation however there is some detail in the primary Word document (at the end).  The bottom line is we apportion and aggregate all the values that can be summed for the ring and then perform the Median and Average and any other calculations using the rings sum totals.

I would starting with the PDF as these are the summed values and then the Word document as an overall detailed description of the calculations.  The Excel file is basically reference to what is described in the Word document.

Let me know if you have an follow up questions.

Regards,

Jason R.