#NYC Tax Data Notes
We are assembling a comprehensive property tax dataset for New York City from publicly available information sources.
The city's property tax bills contain a tremendous amount of data, including how taxes are calculated for each lot and condominium unit, and what extemptions and abatements exist for each.
This repo documents the data cleansing and transformation process.
This project builds on @talos' NYC Stabilization Unit Counts, which sought a subset of exemptions included in a subset of NYC properties in order to get a solid count of rent-stabilized units. To achieve this, he downloaded and archived hundreds of thousands of current and historic tax bills from the New York City Department of Finance (DoF) website. These are available in a borough/block/lot directory structure at taxbills.nyc. The bills were then scraped using a python script to extract the raw data. Read more about the process in the repo's readme.
The rent stabilization project only gathered data for buildings with 6 or more residential units, as those are the only ones subject to rent stabilization laws.
For this project, the intent is to gather 100% of the tax bill data for the entire city for a single year's tax levy. The latest bills were sent on June 5th, 2015. Using the same methodology as in the rent stabilization project we downloaded every bill for June 5th, including those for condominium units, over 1.1 million bills in total.
The output of the script that pulls data from the pdfs is a file called
rawdata.csv, which is avaiable at taxbills.nyc
This contains raw data in a key/value schema, so one bill can produce many rows in this csv, and it includes data from all bills currently archived at taxbills.nyc.
For this project, we'll create two tables from
rawdata.csv. The first,
june15bbls will include the "top-level" data for each BBL (total tax, estimated market value, billable assessed value, etc). `june15exab' will include the exemptions and abatements, which have a many-to-one relationship with BBLs.
CREATE TABLE rawdata ( bbl bigint, activitythrough date, section text, key text, duedate date, activitydate date, avalue text, meta text, apts text )
import using pgadmin>import or whatever method works for you
june15bblsby pivoting the top-level data into one row per BBL. This step includes a join with table called
condolookup, which contains the condominium number for all condo unit and lot bbls. The addition of the condonumber will allow for aggregation of taxes paid by the units of a single condo building. (this lookup table was derived from RPAD)
CREATE TABLE june15bbls as SELECT a.bbl, MAX(CASE WHEN key = 'Owner name' THEN avalue END ) AS ownername, MAX(CASE WHEN key = 'Mailing address' THEN avalue END ) AS address, MAX(CASE WHEN key = 'tax class' THEN avalue END ) AS taxclass, MAX(CASE WHEN key = 'current tax rate' THEN avalue END ) AS taxrate, MAX(CASE WHEN key = 'estimated market value' THEN avalue END )::double precision AS emv, MAX(CASE WHEN key = 'tax before exemptions and abatements' THEN avalue END )::double precision AS tbea, --billable assessed value ended up in the meta column of tbea MAX(CASE WHEN key = 'tax before exemptions and abatements' THEN meta END )::double precision AS bav, MAX(CASE WHEN key = 'tax before abatements' THEN avalue END )::double precision AS tba, MAX(CASE WHEN key = 'annual property tax' THEN avalue END )::double precision AS propertytax, --join with condolookup to include condonum if the bbl is for a condo unit or lot MAX(b.condono) as condonumber, --make a condolot field for easy querying CASE WHEN a.bbl % 10000 > 7500 AND a.bbl % 10000 < 7600 THEN 'lot' WHEN a.bbl % 10000 > 1000 AND a.bbl % 10000 < 7000 THEN 'unit' END AS condo FROM rawdata a LEFT JOIN condolookup b ON a.bbl = b.bbl WHERE activitythrough = '2015-06-05' GROUP BY a.bbl ORDER BY a.bbl
june15exabtable that includes one row per exemption/abatement
CREATE TABLE june15exab AS SELECT bbl, CASE WHEN section = 'details-abatements' THEN 'abatement' WHEN section = 'details-exemptions' THEN 'exemption' END AS type, key as detail, avalue as amount, apts as units FROM rawdata WHERE activitythrough = '2015-06-05' AND ( section = 'details-exemptions' OR section = 'details-abatements' )
A Few Good Queries
Count condos vs non-condos
SELECT condo,count(*) FROM june15bbls GROUP BY condo
Sum all annual tax by borough
SELECT LEFT(bbl::text,1)as borough, SUM(propertytax) as totaltax FROM june15bbls GROUP BY borough
Sum tax before exemptions and abatements, sum annual tax
SELECT SUM(tbea),SUM(propertytax) FROM june15bbls
Group by exemption detail, count and sum
SELECT detail, sum(amount::double precision),count(amount) FROM june15exab WHERE type = 'exemption' GROUP by detail ORDER BY count DESC
There are 147 unique exemption types. There are 42 exemption types with 10 or fewer occurances. There are 7 with only 1 occurrance: indust waste facility, prof. maj lea sports, nys med care fac fin, patrol salvage, solar/wind energy, state retire system, ltd profit hsng co:l
There are only 9 abatement types: "co-op/condo abatement" "j51 abatement" "residential conversion abatement" "solar elec generating system abate" "brooklyn bridge park pilot" "industrial & commercial abate prog" "lease abatement" "mitchell lama star benefit" "icip abatement"
From the FY 2015 tax report, the total levy last year was $21670900000. From our data, the total annual tax from the bills is $21620027503, so we are off by $-50872497 ($50.8M), about .23% lower!