Tax Gap and Tax Enforcement

Publication Date: February 2007

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Banking and finance

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Abstract:

Recent and projected large federal budget deficits have generated congressional interest in the feasibility of raising revenue by reducing the tax gap. The Internal Revenue Service (IRS) defines the gross tax gap as "the difference between the aggregate tax liability imposed by law for a given tax year and the amount of tax that taxpayers pay voluntarily and timely for that year." "The net gap is the amount of the gross tax gap that remains unpaid after all enforced and other late payments are made for the tax year." For tax (calendar) year 2001, the IRS estimates a gross tax gap of $345 billion, equal to a noncompliance rate of 16.3%. For the same tax year, IRS enforcement activities, coupled with other late payments, recovered about $55 billion of the gross tax gap, resulting in a net tax gap of $290 billion.

The estimated gross tax gap of $345 billion consists of underreporting of tax liability ($285 billion), nonfiling of tax returns ($27 billion), and underpayment of taxes ($33 billion). (Taxes on illegal activities are excluded from these estimates.) The $285 billion of underreporting of tax liability has the following components: $197 billion of individual income tax, $54 billion in employment tax, $30 billion in corporate income tax, and $4 billion in estate taxes.

The IRS has replaced the Taxpayer Compliance Measurement Program -- a systematic approach for estimating the tax gap -- with the National Research Program (NRP). One of the guiding principles for the NRP is to minimize the compliance burden on those taxpayers selected in the NRP sample. The new methodology of the NRP was applied to the underreporting gap for the individual income tax for tax year 2001.

The estimates of the gross tax gap have been heavily publicized; perhaps as a result, some public officials have emphasized better enforcement of tax laws in order to raise revenue. Three factors limit the dollar amount that can be collected by increased enforcement. First, much of the gross tax gap for individual income tax filers is due to types of unreported income that are difficult to detect. Second, some of the detected tax liability cannot be easily collected, particularly from those taxpayers who are currently unable to pay. Third, many detected tax liabilities are so small relative to enforcement costs that it is not cost-effective to pursue collection.

From fiscal years 2001 to 2006, greater tax enforcement efforts by the IRS increased enforcement revenue from $33.8 billion to $48.7 billion. The IRS is attempting to reduce the gross tax gap by pursuing a strategy, which has seven components: reduce opportunities for evasion, make a multi-year commitment to research, continue improvements in information technology, improve compliance activities, enhance taxpayer service, reform and simplify the tax law, and coordinate with partners and stakeholders.

This report will be updated as issues develop or new legislation is introduced.