There are numerous abbreviations used throughout the CBO Capital Tax (CapTax) Model code and the documentation. A listing of those abbreviations are in abbreviations.md.
The CapTax Model accepts about 50 files containing a variety of data and parameter values read into the model.
The parameter files and weights data are organized into the following directories:
-
/captax/captax/data/inputs/environment_parameters/
Detailed descriptions of the environment parameters are in environment_parameters.md -
/captax/captax/data/inputs/policy_parameters/
Detailed descriptions of the policy parameters are in policy_parameters.md -
/captax/captax/data/inputs/weights_data
Detailed descriptions of the weights data are in weights_data.md
Some of the parameters are scalars, but others are matrices.
The possible dimensions of those matrices are as follows:
-
Industry
Two levels of detail are used:- Standard industry (61 categories fully reflected in the model’s output)
- Detailed industry (88 categories needed to accommodate the variation in depreciation rules, but not reflected in the model’s output)
-
Asset type
- 83 categories, including five placeholders for additional asset types not recognized in BEA Fixed Asset tables
-
Legal form
- C corporations,
- pass-through entities, and
- owner-occupied housing
(Nonprofits are present as a residual, but no calculations are done on them.)
-
Source of financing
- debt, or
- equity
-
Account category
- fully taxable,
- temporarily deferred, and
- nontaxable
More detailed documentation for the model can be found in a CBO Working Paper: “CBO’s Model for Estimating the Effect of Federal Taxes on Capital Income from New Investment". A short description of modeling changes made after the release of the paper can be found here.