OG-Core

OG-Core is an overlapping-generations (OG) model core theory, logic, and solution method algorithms that allow for dynamic general equilibrium analysis of fiscal policy. OG-Core provides a general framework and is a dependency of several country-specific OG models, such as OG-USA and OG-UK. The model output includes changes in macroeconomic aggregates (GDP, investment, consumption), wages, interest rates, and the stream of tax revenues over time. Regularly updated documentation of the model theory--its output, and solution method--and the Python API is available here.

Disclaimer

The model is currently under development. Users should be forewarned that the model components could change significantly. Therefore, there is NO GUARANTEE OF ACCURACY. THE CODE SHOULD NOT CURRENTLY BE USED FOR PUBLICATIONS, JOURNAL ARTICLES, OR RESEARCH PURPOSES. Essentially, you should assume the calculations are unreliable until we finish the code re-architecture and have checked the results against other existing implementations of the tax code. The package will have released versions, which will be checked against existing code prior to release. Stay tuned for an upcoming release!

Using/contributing to OG-Core

• Install the Anaconda distribution of Python
• Clone this repository to a directory on your computer
• From the terminal (or Conda command prompt), navigate to the directory to which you cloned this repository and run conda env create -f environment.yml
• Then, conda activate ogcore-dev
• Then install by pip install -e .
• Navigate to ./run_examples
• Run the model with an example reform from terminal/command prompt by typing python run_ogcore_example.py
• You can adjust the ./run_examples/run_ogcore_example.py by modifying model parameters specified in the og_spec dictionary.
• Model outputs will be saved in the following files:
  • ./run_examples/run_example_plots
    • This folder will contain a number of plots generated from OG-Core to help you visualize the output from your run
  • ./run_examples/ogcore_example_output.csv
    • This is a summary of the percentage changes in macro variables over the first ten years and in the steady-state.
  • ./run_examples/OUTPUT_BASELINE/model_params.pkl
    • Model parameters used in the baseline run
    • See execute.py for items in the dictionary object in this pickle file
  • ./run_examples/OUTPUT_BASELINE/SS/SS_vars.pkl
    • Outputs from the model steady state solution under the baseline policy
    • See SS.py for what is in the dictionary object in this pickle file
  • ./run_examples/OUTPUT_BASELINE/TPI/TPI_vars.pkl
    • Outputs from the model timepath solution under the baseline policy
    • See TPI.py for what is in the dictionary object in this pickle file
  • An analogous set of files in the ./run_examples/OUTPUT_REFORM directory, which represent objects from the simulation of the reform policy

Note that, depending on your machine, a full model run (solving for the full time path equilibrium for the baseline and reform policies) can take more than two hours of compute time.

If you run into errors running the example script, please open a new issue in the OG-Core repo with a description of the issue and any relevant tracebacks you receive.

The CSV output file ./run_examples/ogcore_example_output.csv can be compared to the ./run_examples/expected_ogcore_example_output.csv file that is checked into the repository to confirm that you are generating the expected output. The easiest way to do this is to use the sh example-diffs command (or example-diffs on Windows) from the run_examples directory. If you run into errors running the example script, please open a new issue in the OG-Core repo with a description of the issue and any relevant tracebacks you receive.

Core Maintainers

The core maintainers of the OG-Core repository are:

• Jason DeBacker (GitHub handle: jdebacker), Associate Professor, Department of Economics, Darla Moore School of Business, University of South Carolina; President, PSL Foundation; Vice President of Research and Co-founder, Open Research Group, Inc.
• Richard W. Evans (GitHub handle: rickecon), Advisory Board Visiting Fellow, Center for Public Finance, Baker Institute for Public Policy at Rice University; President, Open Research Group, Inc.; Director, Open Source Economics Laboratory

Citing OG-Core

OG-Core (Version 0.0.0)[Source code], https://github.com/PSLmodels/OG-Core