About the Data

Data Limitations

This is a brief guide to Data Limitations for users of this Web site. It discusses some of the practical reasons why agency databases may have limitations. It also discusses why information about the quality of government data is often limited or absent. Finally, it highlights some of TRAC's general findings and concerns regarding statistics about Internal Revenue Service enforcement activities.

Why Government Databases May Have Limitations
(and we may not know about them)

Keeping track of the operations of any large bureaucracy is a challenge. This is especially true when the bureaucracy -- like the Internal Revenue Service or the Justice Department - is divided up into numerous semi-autonomous units whose activities are not always subject to uniform or exact definition. It is further complicated when the activities to be tracked involve a large number of field offices which each handle diverse problem areas.

With rare exception, federal law enforcement agencies have computerized data systems to manage workload and track activities. These data systems also usually serve as the main information source for generating operating statistics for both internal and external audiences. Within a single agency, a number of independent databases are usually maintained, often organized along agency division lines.

Some agencies (and units within an agency) do a better job of tracking their important activities than others. But data quality and coverage cost money -- in staff time and computing infrastructure to gather and record the information, to validate and analyze the information, and to continually manage the process. Managing the process is important: to ensure that the information recorded reflects what the agency is doing and keeps up with changes in technology, agency reorganizations, shifting responsibilities, revisions in legal definitions, and even societal changes which all impact how information needs to be recorded.

In a climate of tight budgetary resources, it is not surprising that often resources don't match what's needed to ensure that an accurate and complete accounting of agency activities occurs. Often little attention is given to whether the data generated from agency computer systems are accurate -- particularly if inaccuracies don't cause obvious problems for agency managers. Thus, while the Internal Revenue Service devotes considerable time and effort to matching income reports on taxpayer returns with information reported by third parties about payments made to taxpayers, much less effort is devoted to determining whether the revenue IRS claims to generate through its tax audits ultimately ever gets assessed and actually collected. Where no money is being tracked and a data system is used primarily to count the agency's "successes" -- in the number of completed cases, referrals passed on, or criminal convictions -- there may be an active disinterest in checking too closely so long as the number of recorded successes keeps rising at the desired pace.

What may be surprising is that often little attention is given by institutions of oversight such as Congress and the General Accounting Office to the accuracy of data systems when "actions" rather than "money" are being tracked. Usually, the agency's counts are accepted at face value and used as the basis for appropriations as well as new legislative initiatives, with little investigation or probing of what lies under the hood. As a result of this combined disinterest on the part of both the agency and our watchdogs, we often have little solid knowledge about how accurate and complete (or inaccurate and misleading) most agency statistics actually are.

Accuracy and Completeness of IRS Enforcement Statistics
(what we do know)

Without access to the underlying detailed agency transactional records, it is often very difficult to judge the quality of statistics received from government sources. Discussed elsewhere (see Judging the Quality of Government Data) are three types of general indicators TRAC employs in its research.

  • Statistics on Tax Audits

    TRAC knows of no systematic study on the reliability of IRS counts of audits and their distribution among districts and taxpayer classes. But several areas of concern can be noted.

    First, audit counts can be misleading for a number of reasons. In 1994 IRS changed its definition of what it counts as an "audit," and recalculated its audit numbers using this new definition back to 1988. It now counts all contacts of taxpayers by correspondence by tax examiners from its Service Centers as audits. These are typically generated by computer matching of returns with third-party information to spot potential discrepancies. In examining audit rates, it is thus very important to recognize that an "audit" means something very different today then it did a few years ago.

    This has a number of further implications. Audit rates have become extremely variable from one year to the next, since it doesn't take much resources to jack up computer-generated Service Center audit counts. (See graph.) Comparing audit coverage across classes of taxpayers has also become more problematic. While all may count equally as an "audit," they may imply very different activities and levels of thoroughness in the examination of a taxpayer's books and papers.

    While the growth in Service Center audits makes this problem especially troubling in the audit of wage-earner returns, the variability in the thoroughness of audits has always been an important issue with business and corporate returns. For example, just because most large corporate returns are examined, doesn't necessarily imply that equally thorough audits take place. The audit of small businesses can be more thorough because it is so much easier to examine all relevant transactions for a small businessman than it is for a multi-national corporation.

    Second, the dollar amounts IRS reports as resulting from its audits also can be very misleading. This is because the figures IRS reports are usually based upon initial audit recommendations, not final assessments or amounts ultimately collected. There can be a large difference between these initial recommendations and final assessments and collections. When significant dollar amounts are at stake, taxpayers have sufficient financial incentive to contest IRS auditor recommendations. Such appeals are surprisingly successful and result in large reductions from initial audit recommendations to final assessments. (See tables.)

    While not a problem with the statistics per se, it is important to note that changes in under-reporting found during audits don't imply changes in tax evasion, or even in taxpayer noncompliance more generally. This is primarily because these changes are driven by the volume (and targeting) of IRS enforcement activity -- not underlying changes in taxpayer compliance. It should also be remembered that because IRS turns up tax under-reporting, it doesn't necessarily mean that the taxpayer committed tax evasion or even in fact misreported his or her taxes. A very substantial amount of what IRS records as "noncompliance" occurs because complexities in the law give rise to more than one defensible interpretation of the amount of tax that is truly owed.

  • Statistics on Criminal Enforcement

    Serious problems in the data systems IRS uses to track criminal enforcement activities are well documented, and have existed for over a decade. As a result, the information provided the public by the Internal Revenue Service about the agency's criminal enforcement activities are substantially inaccurate. Taken as a whole, the data provide a highly misleading picture of the enforcement efforts of one of the IRS's most important components, the Office of Criminal Investigation. See Misleading and Inaccurate IRS Data and IRS Criminal Enforcement Data Systems where these problems are discussed in detail.

    Because these data cannot be relied upon to describe IRS's criminal enforcement efforts, we have not used them on this Web site. Instead, information from federal prosecutor tracking systems along with those of the Administrative Office of the United States Courts have been used.

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