These documents provide a description of the Tax Policy Center's microsimulation model of the federal tax system and materials to help understand and interpret our estimates.

• FAQ
  Answers to common questions about TPC's tax simulation model, the estimates it generates, and the organization of tables in our database.
• Brief Description of the Tax Model
  Updated on March 9, 2022. The Urban-Brookings Tax Policy Center’s large-scale microsimulation model produces revenue and distribution estimates of the U.S. federal tax system.
• Description of TPC’s Business Tax Model
  Updated on August 10, 2018.
• TPC’s Methodology for “Off-Model” Revenue Estimates
  The Urban-Brookings Tax Policy Center (TPC) uses its large-scale microsimulation model to produce “on-model” revenue estimates of nearly all proposals...
• How to Interpret Distribution Tables
  TPC's distribution tables provide quantitative information on the way in which tax proposals affect different groups of individuals. Ideally, we...
• Explanation of Income Measures
  Tax Policy Center (TPC) uses a broad measure of pre-tax income, which we call “expanded cash income” or ECI, to...
• Explanation of Baselines
  Current law refers to the law currently scheduled for a given year — that is, the law that will prevail if Congress does not act...