TaxData now offers two datasets created to run in the open source Tax-Calculator:
PUF.csv and CPS.csv. Both files are representative micro-datasets containing
tax unit level data. The key differences are the sources used to create each file
and the aggregate results and distributions.
The PUF is created using a statistical match between the IRS-SOI Public Use File and the Census Current Population Survey. The use of IRS-SOI data is restricted and therefore we cannot provide access to them to the general public.
The CPS is created using the Census Current Population Survey, Annual Social and Economic Supplement data for March 2013, 2014, and 2015. Household and family information from the surveys are used to create tax units based on income and relationship data. Because the CPS is not designed for tax reporting purposes, results from constructed tax units are expected to be different from PUF in term of both aggregates and distribution. In addition, the CPS includes very limited high income households and has under-coverage issues in lower income households. Therefore, the wage distribution of CPS is different from that of PUF. Additional data on welfare and transfer program participation and benefits is added to the CPS using the open source CPS Transfer Augmentation Model (C-TAM). C-TAM is used to impute benefit values for SNAP, SSI, Social Security, Medicare, Medicaid, veterans benefits, housing assistance, TANF, and WIC.
Because benefit data is imputed onto the CPS, it is not available in the PUF. Similarly, the CPS is missing some income and deduction variables only available in the PUF.
A full list of variables available in each file can be found
here. The
availability of each variable is specified in the availability section. PUF
availability is indicated by taxdata_puf, CPS availability by taxdata_cps.
Due to missing variables, certain policy parameters will be ineffective depending on which file you're using. These will be greyed out in TaxBrain. The policy parameters available in Tax-Calculator can be found in here. The dataset(s) compatible with each parameter are indicated by true/false values in the Has An Effect When Using section.
The weighted totals of each variable will differ between the two datasets. Totals by year for the CPS can be found here. For the PUF, here.