This congressional committee – unlike most – does not have separate Democratic and Republican staffs. It was set up in 1926, when the federal income tax in its present form was only 13 years old. Congress sought professional analysis independent of the Treasury Department, which is run by a political appointee named by the president. The Joint Tax Committee uses a sophisticated, computerized microsimulation model of the U.S. federal income tax system, based on information from a random sample of 200,000 tax returns each year, to project the likely effects of proposed changes in tax law.
The main page of the website links directly to text of the committee’s most recent reports and transcripts of hearings. The site also features a table of contents that offers links to the committee’s publications sorted by year.
The committee provides authoritative revenue projections – estimates of how much (in dollars) the government’s income is likely to change as a result of a proposed change in tax law. It also offers good, plain-language descriptions of how a particular tax proposal would work. But the committee provides only limited “distributional analysis” – estimates of how people at various income levels will fare.