shrug-l: Scoring residential tax parcels for COVID-19 risk?

Rick Labs rick at
Fri Apr 17 16:27:33 EDT 2020

Thinking out loud here. Really just brainstorming. Sorry this is long 
and a bit "wandering" but that's the nature of research.

How might we score residential tax parcels for COVID-19 risk 
appropriately, with an eye towards limited surveillance testing resources?

First we need to know - is any resident of that tax parcel a COVID-19 
"vulnerable person"?

*#1 Elderly individuals.*
*#2 Individuals with serious underlying health condition**s*
(or both)

On the "Elderly" factor we have Census data, including the 2020 Census 
that is related to a Master (postal) Address File and asks the question 
specifically: (for each person living in that household) /"What is 
Person 1's age and what is Person 1's date of birth?/...." Of course 
Census data is for the most part totally unavailable at such a granular 
level, this however might be an excellent "exception".

On a secondary basis we might proxy "age of resident" by number of years 
the house was owned from when it was last purchased? That obviously 
would miss a great number of elderly residents, renters, etc. *
**Qualified medical conditions *(Individuals with serious underlying 
health conditions)

"Individuals with serious underlying health conditions, including

  * high blood pressure
  * chronic lung disease
  * diabetes
  * obesity
  * asthma, and
  * those whose immune system is compromised such as by chemotherapy for
    cancer and other conditions requiring such therapy."

Thinking off the top of the head, could prescription drug purchases 
identify many of those individuals?

Of course confidentiality of CENSUS and health care information would be 
a huge issue.

The above are just the two easiest to understand criteria.

Heroic assumption: the (one or more) "Vulnerable Person(s)" is fully 
informed, responsible, sheltering in place and following all CDC 
guidance. (later this assumption can be relaxed.) Then the question 
becomes, */who else lives in that household/***and how "exposed" are 
they during their typical day? Are they possibly asymptomatic or with 
very mild symptoms, fully at risk of inadvertently bringing COVID-19 
through the front door, exposing the 1+ /vulnerable /people who live there?


  * a greater number of residents in the household who are "out and
    about" increases the chance /any one /will carry COVID-19 in.
  * if a resident is a front line health care worker the risk goes up
    (but the awareness/knowledge/compliance might also be better?)
  * if a resident works in an "essential business" there is a greater
    chance they have been exposed on the job, or will be exposed
  * has a resident traveled through / lingered in any known hot spot?
  * more youthful/healthful residents are the MOST likely to carry, but
    remain asymptomatic (and hence the least tested group so far.)
  * if a resident is employed in a "non-essential business" they may
    have been sheltering at home in the recent past, BUT are about to
    return to work. How will all that play out?

*Classic Demographics*

We can easily factor in some great Census data at the Block Group level 
to identify residential parcels that score high on demographic data that 
is well known to correlate highly with COVID-19 severity, items such as:

  * household income
  * ethnic origin
  * residential density
  * urban / rural differentials
  * air quality? (as a proxy for lung disease and asthma - e,g, LA, NY,
    air quality measures?)

*Local transportation statistics*

I'm not familiar with this area at all so I can only speculate. I'm 
aware of CENSUS commuter statistics regarding commuters living in one 
county and working in another (commuting across county lines for work 
every day).

Very large employers commuter maps may have been constructed as large 
employment centers were modeled added or subtracted?

License plate capture on toll / traffic cameras?

Again, I have no solid background here but I speculate transportation 
experts might have "network models" that could be juiced to contribute 
an individual COVID-19 tax parcel risk score?

*Classic Marketing Data**
*Marketing in the USA is very sophisticated. Much is well known about 
each postal address, including past purchases by product type, brand 
preferences, estimated ages of residents at that address, etc. (Next to 
CENSUS data this data set is pretty granular and accurate.)

For instance I'm sure its possible to get postal lists of heavy buyers 
of OTC medications for allergy/asthma/lung disorders (or any of the 
other conditions above). And that's just a start...

Credit card data could also be useful. Especially in real time.

*Cell phone location tracking**
They know where you are, when, and for how long you stayed. They know 
where that phone sleeps. They infer if you are in a car vs. walking vs. 
riding a bike vs. in a kayak....

Some of that data is already VERY widely available to marketers. Some 
studies might be run by the "data holders" that do not actually reveal 
/personal identity/, but may be linked (with relative ease) to postal 
address. Obviously there are great sensitivities here. However if the 
relationship were "many-to-many" it probably would fly.

Example to make it "many-to-many" - build up a "points system":

  * traveled to any of the following locations and remained more than 1
    day in the past 90 days: 10 points
  * traveled to and spent time at a known drug store 3 standard
    deviations higher than average in the past month: 5 points
  * owns a cell phone and uses it more than x times per week but
    otherwise shows very little movement around, does not use much data.
    (proxy for obesity and/or old age). 15 points
  * watches more than 4 hours of daytime TV. 15 points
  * does not have a cell phone and does not have any form of Internet,
    yet lives in a wired/urban location: 20 points
  * ...more like above

Data vendor runs the analysis and gives you the top scoring 5% of your 
county population, as just a list of post office addresses, given back 
to you in random order.

County sends post cards... "/Your household may be at elevated risk - 
more info available by phone or on the Internet...FREE CONFIDENTIAL 
TESTING. Only requires a mouth swab, available TODAY! Takes only 15 

Any other ideas how to create a tax parcel score for COVID-19 risk?

Above of course would be pretty much a hypothesis to begin with. Would 
want to close the loop with actual surveillance testing results. Then 
"train the model" further with even wider data to try to improve the pin 



Richard J. Labs, CFA, CPA
CL&B Capital Management, LLC
Phone: 315-637-0915
E-mail (preferred for efficiency): rick at
3213 Yorktown Dr, Tallahassee, FL 32312-2015
June-August: 408B Holiday Harbour, Canandaigua, NY 14424

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