FortaxA UK microsimulation tax project

Imagen Imagen Imagen

The FORTAX project is centered around the development of the FORTAX library, a micro-simulation tax library programmed in Fortran. It represents an on-going research project that aims to provide researchers the ability to calculate detailed representations of the UK tax and transfer systems over time, incorporating the complicated rules and interactions. The library is highly efficient and flexible, and is ideally suited to applications where accurate budget sets or components of income need to be calculated repeatedly. The estimation and simulation of labour supply models are therefore natural candidates for the use of FORTAX.

Here you may download code that is part of the FORTAX project. Please let me know if you are using FORTAX. Research papers that use FORTAX in any form should cite the reference manual that is provided with the main FORTAX Library (available here). Unless stated otherwise, all code here is released under the GNU General Public License version 3 (GPLv3).

FORTAX Library

This is the main Fortran FORTAX library written with Jonathan Shaw, and used in all the derivative works below. Users who program in Fortran and wish to use FORTAX for labour supply estimation/simulation should use this library. It is also required if you are the compiling supporting programs from source. I do not supply any compiled versions of the library.

[source code repository] [reference manual] [uk system manual]

FORTAX for Stata

FORTAX for Stata provides a convenient way of accessing the Fortran FORTAX library from within Stata. It makes use of the Stata Plugin Interface and allows users to calculate very detailed income measures under a range of UK tax and transfer systems. While FORTAX for Stata only has limited functionality compared to the main FORTAX library, it is still able to calculate the income components that will be required in many empirical applications. Once installed, type "help fortax" within Stata for details on using FORTAX for Stata. The plugin is coded in C++, which then calls the Fortran compiled FORTAX library. The code therefore provides an example showing how Fortran code may be called via the Stata Plugin Interface. The compiled plugin is provided for Windows (32-bit) and can be compiled from source for other platforms (see here and the accompanying makefile for details).

[stata .ado and .plugin files] [c++ and fortran source code]

FORTAX Calculator

The FORTAX Calculator allows users to easily calculate accurate budget constraints and components of incomes in an intuitive graphical environment. Results can easily be exported from the application, and graphical budget constraints can be drawn. The application also facilitates the comparison of incomes under different tax and transfer systems. Requires the main FORTAX library together with Python 2.6 or above and the Qt GUI toolkit. It calls the main FORTAX library to calculate incomes and budget constraints, and is linked to Python using F2py. The graphical functionality is provided by matplotlib).

[python and fortran source code] [calculator user guide]


FORTAX Online provides an interactive web-based interface that allows users to calculate both income schedules and detailed components of income. A test version is available here.