The Tax-Calculator simulates the US federal individual income tax system. In conjunction with micro data that represent the US population and a set of behavioral assumptions, the Tax-Calculator can be used to conduct revenue scoring and distributional analyses of tax policies. The Tax-Calculator is written in Python, an interpreted language that can execute on Windows, Mac, or Linux.
Results will change as the underlying models improve. A fundamental reason for adopting open source methods in this project is so that people from all backgrounds can contribute to the models that our society uses to assess economic policy; when community-contributed improvements are incorporated, the model will produce different results.
At the moment there are three ways to start using the Tax-Calculator.
The first way is to install the Tax-Calculator repository on your
computer. Do this by following the instructions in our Contributor
Guide
and then reading about our testing procedures. This way
allows you to read the source code and contribute enhancements to the
source code. While this way does not provide you with a
representative sample of tax filing units, it does allow you to
estimate tax liabilities and marginal tax rates for any collection of
filing units specified in Internet-TAXSIM input
format using the
simtax.py command-line interface to the Tax-Calculator.
The second way is to access the Tax-Calculator through our web application, TaxBrain. This way allows you to generate aggregate and distributional tax reform estimates using a nationally representative sample of tax filing units that is not part of the Tax-Calculator repository.
The third way, which is for advanced Anaconda users, involves
installing the taxcalc package on your local computer. A new taxcalc
package is generated for every release of the Tax-Calculator. We use
the package to install taxcalc on Amazon Web Services (AWS) instances
that run the TaxBrain web application. You can get the latest release
of the Tax-Calculator to run on your computer via the command conda install -c ospc taxcalc. Note that this package does not include a
representative sample of the US population. Also, note that there is
some skill involved in Getting Started the first way and installing
the taxcalc package on the same local computer, which is why we
describe this way as being for advanced Anaconda users.
And, of course, you can get started with any combination of these three ways of using the Tax-Calculator.