PVR can, in principle, help to mitigate problems arising from a major source of duplicate registrations in a statewide VRD—registered voters who change address.

PVR does not necessarily have implications for the design of a VRD. There is no reason that a voter’s change-of-address form must be entered into the VRD on Election Day—only that the voter be allowed to vote (preferably based on the new address). It does mean that poll workers must have access to the statewide VRD (or a suitable local copy of it, such as one in paper form or more likely as a DVD or CD-ROM that can be loaded on a personal computer at the polling place) in order to confirm that a voter was indeed previously and properly registered.


Proposals are sometimes made to establish a national voter registration database. In principle, such a database could serve one of two purposes. First, it could be used to coordinate statewide VRDs to eliminate duplicate voter registrations across state lines and to facilitate interstate portability of voter registration. Second, it could be used in support of universal or automatic voter registration—an approach to voter registration in which the need for individuals to take affirmative action to register to vote is eliminated by shifting the burden of voter registration to the states in which these individuals reside.12

Conceptually, the first purpose is an extension of intrastate portability of voter registration. As noted in Section 3.7, statewide VRDs can facilitate intrastate portability and help to address problems arising from duplicate voter registrations within a state. A national VRD for this purpose could easily be constructed by amalgamating the statewide VRDs of all states and other voting districts and using the statewide VRD data export functions to move the data to the national VRD. Such a database would have to contain some 150 million to 200 million entries (the number of registered voters in the United States), and thus would be approximately 10 times as large as the largest statewide VRD in existence today.

Despite its larger size, however, performing list management (specifically—eliminating duplicates) on such a database is a relatively straightforward computational task. This task could not be managed on a single personal computer commercially available today in a reasonable time, but a mid-size departmental computer using commercially available software and a few dozen terabytes of disk storage would be able to do so with ease. Alternatively, generally available cloud computing services (an example of which is the Amazon Elastic Compute Cloud13) could be employed to perform the computational task. Cloud computing has the advantage of eliminating the need for capital investment in hardware. On the other hand, cloud computing is not a technology with which either the public or election administrators have much experience, and thus the use of cloud computing may suffer from a lack of transparency.

The substantially larger size of a national VRD would result in a large number of pairs of entries flagged as possible duplicate registrations. Even with a match rule based on an exact character-by-character matching on first name, last name, and date of birth, it can be expected that around 480 coincidental matches (that is, different individuals who share the same first name, last name, and date of birth) would be identified in comparing VRD lists from Oregon and Washington alone.14

The use of a universal national identifier would significantly increase the accuracy of any process


See, for example, Wendy Weiser and Margaret Chen, “America’s National Embarrassment: Why Is the Rest of the World So Much Better at Signing up the Vote?,” Foreign Policy, July 29, 2009, available online at http://www.foreignpolicy.com/articles/2009/07/29/americas_backward_voter_registration_system. Note, however, that advocates of universal or automatic voter registration do not necessarily support a national VRD, and a national VRD is not a necessary component of universal voter registration. For example, Weiser also argues that a national VRD could prove costly and unwieldy, and errors in such a database might improperly disenfranchise voters. Eliza Newlin Carney, “Looking Abroad for Answers on Voter Registration,” National Journal, July 20, 2009.


See http://aws.amazon.com/ec2/.


This estimate is based on the fact that individuals with a common name such as “Sharon Smith” may coincidentally agree on date of birth.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement