GeoRegionValuePlot Leaving Out Metropolitan Census Tracts

Question

Preamble

Run this code in the preamble for a working example of what I'm dealing with.

Census Tract Entity Store

ResourceData[ResourceObject["Census Tract Entity Store"]]; // Quiet
EntityRegister[ResourceData[ResourceObject["Census Tract Entity Store"]]]; // Quiet

Function Declaration

f[x_] := EntityValue[EntityClass["CensusTract", "ADM2" -> x], 
   EntityProperty["CensusTract", "B19013_001E"], "Association"] // 
  Quiet

List of Counties

Click here for Pastebin of list of counties. You have to run this code in order for this example to work.

Question

Take a look at the following line of code. It generates a map of the census tracts in the DMV area, colored by income. When I run it, having run all the code above first, I am seeing that D.C. and Baltimore are blank. See the areas I'm talking about circled in blue in the figure below. (I added the blue circles after the fact)

GeoRegionValuePlot[<|Map[f, dmvCounties]|>, ImageSize -> 500]

My question is: why are D.C. and Blatimore blank? How can I include them in this map as well?

Answer 1

If you look at the output of Map[f, dmvCounties], you can see that there are several counties where the value is Null or Missing.

a = <|Map[f, dmvCounties]|>

Sort[a][[-50 ;;]]

I don't see DC in the output but it does look like there's a "Baltimore County" value that is null. Another way to have a look is by just plotting all the keys:

GeoListPlot[Keys@a, PlotStyle -> Blue]

Clearly something missing.

A final check is to simply run f on the entities you are missing:

GeoRegionValuePlot@
 f[Entity["AdministrativeDivision", {"BaltimoreCounty", "Maryland", 
    "UnitedStates"}]]

while f@Entity["City", {"Washington", "DistrictOfColumbia", "UnitedStates"}] just returns <||>.

Sorry I don't have a solution as to how you can include them, but the why seems that there may be no data in the dataset for those Entities.