The Taxpayers Estimate is Truth in Accounting's estimate of the number of individual taxpayers with a positive income tax liability in the states and cities. The Taxpayers Estimated in the U.S. is the estimated number of taxpayers with a positive income tax liability in the entire country. These estimates are based on the individual income tax filings reported by the Internal Revenue Service.
Each year, the Internal Revenue Service (IRS) releases data regarding federal income taxes, including the number of filers in each state and characteristics of various filers. However, the data often lags by a year or two, so TIA estimates the current of taxpayers by multiplying the IRS figure by a state's population growth rate.
To calculate a municipal government's number of taxpayers, the municipality's estimated population is multiplied by the percentage of the estimated state population with a positive income tax liability.