A Few Words About Voting Age Population (VAP)

The term Voting Age Population (VAP), refers to the total number of persons in the United States who are 18 years of age or older regardless of citizenship, military status, felony conviction, or mental state. The standard source of VAP figures is the Bureau of Census, as reported in their Current Population Reports, Series P-25.

Extreme care must be taken when using VAP figures as a basis for measuring voter participation in elections for federal office. The actual number of eligible voters, those that are legally entitled to vote, will always be less than the VAP because of the inclusion of resident aliens (both legal and illegal), as well as convicted felons who are either institutionalized or who have not yet had their voting rights restored under the various State laws, persons declared non-compos mentis by a court of law, or those persons otherwise ineligible to vote. Neither the Bureau of Census nor any other organization can define with complete accuracy exactly how many eligible voters there are in the United States. According to 1994 estimates, approximately 13 million persons over the age of 18 were not U.S. citizens. (Non citizens make up the largest group of ineligible voting age persons. In contrast, the next largest group, institutionalized felons, who are prohibited by State law from voting in all but 4 States, numbered only about 1.2 million at the end of 1996.) In spite of these shortcomings, the lack of accurate eligibility figures requires political analysts to employ voting age population as a base number for comparisons of participation in the political process.

The other significant variable one must keep in mind when dealing with VAP is the fact that the Bureau of Census actually uses 3 separate sets of voting age population figures in any given federal election:

• Projected Voting Age Population
• Estimated Voting Age Population
• Current Population Survey

The Projected Voting Age Population is provided by Census in the Spring of each election year. These figures are only "quick and dirty" extrapolations from previous data and are therefore unofficial approximations. These figures include members of the armed forces where they reside at their duty stations, but exclude the military and civilian population overseas and their dependents of voting age who would be eligible to vote by absentee ballot in their home State. These early figures are used primarily to satisfy the needs of the news media and political strategists.

The Estimated Voting Age Population are based on a sample survey conducted in the Summer of the election year and are thus "official" estimates as of July 1st and are certified as such by the Commerce Department. These figures include military and institutionalized populations but (in 1996) were not adjusted for the 4 million undercount in the 1990 census. The value of these statistics lies in their utility to government agencies like the FEC who must use them, especially in Presidential election years, for certain financial purposes.

Current Population Survey numbers are generated by Census each month based on extrapolations from the previous years estimates. In contrast, these figures do not include military or institutionalized persons, but are adjusted for the 4 million undercount.

For statistical purposes, the Federal Election Commission has opted to use the Current Population Survey figures for its report to Congress on the NVRA largely out of professional convention. These are the figures employed by the Congressional Research Service of the Library of Congress as well as by Election Data Services, Inc..  Moreover, these are the most frequently cited sources in other private publications such as those from the Committee for the Study of the American Electorate and Congressional Quarterly.