Monday Map: Effective Federal Income Tax Rates by Zip Code

December 5, 2011

Download Effective Rates by Zip Code, Sorted

Today's Monday Map shows the average effective federal income tax rate in each zip code of the United States. Data for this map comes from the IRS's income tax zip code data.


Click on the map to enlarge it.

The general pattern is what one would expect – wealthier areas tend to pay higher rates, and poorer areas tend to pay lower rates.

Next week, I'll try and bring you a map that controls for this effect – the plan is to fit a trendline to a plot of income per capita vs. effective tax rate, and color the map based on deviations from the "expected" rate based on income. That should produce a good visual representation of particular regions of the country that are paying more or less than they "should" be paying based only on their per capita income.

Note that this map shows federal income tax only, and does not include state taxes of any kind or other federal taxes (such as payroll.)

Update: Mary O'Keefe describes this map as "mind-boggling" and wonders if it can possibly be right. Specifically,

Although the American public might well be inclined to accept it at face value, I don't see how this map can possibly be right, unless there is something extremely weird going on in residential segregation patterns when broken down by zipcodes.

Perhaps I am colorblind, but it appears to me there are many zipcodes showing up in maximally bright blue on the map. I'd really like to see the data behind this map, because it is very hard for me to discern the variations in subtle colorations.

I'll happily post the raw data sorted by effective rate. I'll tentatively speculate that the confusion here is a result of how the eye perceives color, because there are very few zip codes in this map that are the deepest shade of blue (corresponding to 25% or above.) However, when an urban blueish area is surrounded by a sea of yellow, the eye perceives it as bluer than it is because of the contrast with the surrounding areas. The bluest part of an urban area is perceived as "maximally blue," but it's a local maximum, not a global maximum, and doesn't actually correspond to the 25% ceiling.

View previous Monday Maps here.

Related Articles