Selected historical and other data - Illustration

Statistics of Income Bulletin, Summer, 2003

General notations and statements

N/A--Not applicable.

n.a.--Not available.

p--Preliminary.

r--Revised or corrected.

*--Estimate should be used with caution because of the small number of sample returns on which it is based. See "Appendix--SOI Sampling Methodology and Data Limitations."

**--Not shown to avoid disclosure of information about specific taxpayers. However, the data are combined with data in an adjacent size class, as appropriate, and included in the appropriate totals.

Detail may not add to totals because of rounding. All amounts are in current dollars. Percentages shown in some of the tables are based on dollar amounts rounded to the units indicated in the specific table headings. Therefore, they may not be as precise as percentages based on the fuller dollar amounts found in tables contained in the source publications or articles which underlie the historical tables presented in this section of the Bulletin.

In the data sources listed at the end of the footnotes, which cite a Statistics of Income publication or unpublished table, the following should be noted: Most of the data are subject to sampling error; tax law and tax form changes affect the year-to-year comparability of the data; and specific Statistics of Income reports cited include more complete discussions of sampling error and of other changes affecting comparability of the data.

See, also, the appendix to the Bulletin for a general description of "SOI Sampling Methodology and Data Limitations."

Footnotes

Table 1

[1] Year-to-year comparability of the "all returns" total is affected by changes in dollar income filing thresholds, while year-to-year comparability of the number of returns by type of tax form used is affected by changes in the specific filing requirements, including adjustments for inflation, for each form. In general, the filing of "short forms" (mostly Form 1040A; then Form 1040EZ, starting with 1982; and Form 1040-T, for 1995 only) has been encouraged by IRS to simplify both taxpayer filing requirements and IRS processing. Filing requirements for each of the short forms have, therefore, been gradually liberalized to facilitate their use. Increases in the number of short forms by type of form have mostly been at the expense of "long form" 1040 usage (although increases in the number of each of the short forms have often been at the expense of one short form over another). While the number of 1040 (paper) returns has, therefore, increased over the time period shown, the rate of increase has been reduced by the growing use of the short forms, and, later, by electronic filing options (see below), including, for 1991-1999, use of Form 1040PC. For additional information about the return tiling requirements, see the annual reports, Statistics of Income--Individual Income Tax Returns.

Forms 1040, 1040A, and 1040EZ include "standard" electronically-filed ("ELF" or "e-file') returns, starting with Tax Year 1985, and Form 1040EZ returns filed electronically by telephone ("TeleFile"), starting with 1991. Prior to Tax Year 1994, data for these forms also include computer-generated "paper" returns (Form 1040PC) that were reclassified as Forms 1040, 1040A, or 1040EZ returns for Statistics of Income, depending on the filing characteristics of each return. Because Form 1040PC returns were not reclassified for Statistics of Income for 1994-1999, data for Forms 1040, 1040A, and 1040EZ for these years are not comparable with the preceding years. (Form 1040PC did not apply after 1999.) (However, some reclassified data for 1994-1999 may be found elsewhere, in most articles presenting projections of returns to be filed, in Winter issues of the Bulletin, starting with the 1993-1994 issue, Volume 13, Number 3.)