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Elections: Issues Related to State Voter Identification Laws [Reissued on February 27, 2015]

GAO-14-634 Published: Sep 19, 2014. Publicly Released: Feb 27, 2015.
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What GAO Found

The studies GAO reviewed on voter ownership of certain forms of identification (ID) documents show that most registered voters in the states that were the focus of these studies possessed the selected forms of state-issued ID, and the direct costs of required ID vary by state. GAO identified 10 studies of driver's license and state ID ownership, which showed that estimated ownership rates among all registered voters ranged from 84 to 95 percent, and that rates varied by racial and ethnic groups. For example, one study estimated that 85 percent of White registered voters and 81 percent of African-American registered voters in one state had a valid ID for voting purposes. The costs and requirements to obtain certain forms of ID, including a driver's license, state ID, or free state ID, vary by state. GAO identified direct costs for these forms of ID in 17 states that require voters to present a photo or government-issued ID at the polls and do not allow voters to affirm their own identities, and found that driver's license direct costs, for example, range from $14.50 to $58.50.

Another 10 studies GAO reviewed showed mixed effects of various forms of state voter ID requirements on turnout. All 10 studies examined general elections before 2008, and 1 of the 10 studies also included the 2004 through 2012 general elections. Five of these 10 studies found that ID requirements had no statistically significant effect on turnout; in contrast 4 studies found decreases in turnout and 1 found an increase in turnout that were statistically significant.

GAO conducted a quasi-experimental analysis to compare voter turnout in Kansas and Tennessee to turnout in the four comparison states that did not have changes in their voter ID requirements from the 2008 to 2012 general elections. In selecting these states from among 14 potential states that modified their ID requirements and 35 potential comparison states, GAO applied criteria to ensure that the states did not have other factors present in their election environments that may have significantly affected turnout. GAO selected states that did not experience contemporaneous changes to other election laws that may have significantly affected voter turnout; had presidential general elections where the margin of victory did not substantially change from 2008 to 2012 and all other statewide elections, such as U.S. Senate races, were non-competitive in both the 2008 and 2012 general elections; and ballot questions were not present, noncompetitive, or similarly competitive in both the 2008 and 2012 general elections. GAO analyzed three sources of data on turnout among eligible and registered voters, including data from official voter records and a nationwide survey. GAO's evaluation of voter turnout suggests that turnout decreased in two selected states—Kansas and Tennessee—from the 2008 to the 2012 general elections (the two most recent general elections) to a greater extent than turnout decreased in the selected comparison states—Alabama, Arkansas, Delaware, and Maine. GAO's analysis suggests that the turnout decreases in Kansas and Tennessee beyond decreases in the comparison states were attributable to changes in those two states' voter ID requirements. GAO found that turnout among eligible and registered voters declined more in Kansas and Tennessee than it declined in comparison states—by an estimated 1.9 to 2.2 percentage points more in Kansas and 2.2 to 3.2 percentage points more in Tennessee—and the results were consistent across the different data sources and voter populations used in the analysis.

To further assess the validity of the results of this analysis, GAO (1) compared Kansas and Tennessee with different combinations of comparison states and with individual comparison states, and (2) controlled for demographic characteristics that can affect turnout, such as age, education, race, and sex. GAO also conducted an analysis using survey data on registrants from Kansas and Tennessee and a nationwide comparison group of all states other than the selected comparison states. These additional analyses produced consistent results. GAO's estimates are limited to turnout in the 2012 general election in Kansas and Tennessee and do not apply to other states or time periods.

GAO also estimated changes in turnout among subpopulations of registrants in Kansas and Tennessee according to their age, length of voter registration, and race or ethnicity. In both Kansas and Tennessee, compared with the four comparison states, GAO found that turnout was reduced by larger amounts:

  • among registrants, as of 2008, between the ages of 18 and 23 than among registrants between the ages of 44 and 53;
  • among registrants who had been registered less than 1 year than among registrants who had been registered 20 years or more; and
  • among African-American registrants than among White, Asian-American, and Hispanic registrants. GAO did not find consistent reductions in turnout among Asian-American or Hispanic registrants compared to White registrants, thus suggesting that the laws did not have larger effects among these subgroups.

A small portion of total provisional ballots in Kansas and Tennessee were cast for ID reasons in 2012, and less than half were counted. In Kansas, 2.2 percent of all provisional ballots in 2012 were cast due to ID reasons, and 37 percent of these provisional ballots were counted. In Tennessee, 9.5 percent of all provisional ballots in 2012 were cast due to ID reasons and 26 percent were counted. Provisional ballots cast for ID reasons may not be counted for a variety of reasons in Kansas and Tennessee, including the voter not providing valid ID during or following an election. GAO's analysis showed that provisional ballot use increased between the 2008 and 2012 general elections by 0.35 percentage points in Kansas and by 0.17 percentage points in Tennessee, relative to all other comparison states combined; these findings are not generalizable.

Challenges exist in using available information to estimate the incidence of in-person voter fraud. For the purposes of this report, “incidence” is defined as the number of separate times a crime is committed during a specific time period. Estimating the incidence of crime involves using information on the number of crimes known to law enforcement authorities—such as crime data submitted to a central repository based on uniform offense definitions—to generate a reliable set of crime statistics. Based on GAO's review of studies by academics and others and information from federal and state agencies, GAO identified various challenges in information available for estimating the incidence of in-person voter fraud that make it difficult to determine a complete picture of such fraud. First, the studies GAO reviewed identified few instances of in-person voter fraud, but contained limitations in, for example, the completeness of information sources used. Second, no single source or database captures the universe of allegations or cases of in-person voter fraud across federal, state, and local levels, in part because responsibility for addressing election fraud is shared among federal, state, and local authorities. Third, federal and state agencies vary in the extent they collect information on election fraud in general and in-person voter fraud in particular, making it difficult to estimate the incidence of in-person voter fraud.

In comments on draft report excerpts the Kansas, Tennessee, and Arkansas Secretary of State Offices disagreed with GAO's criteria for selecting treatment and comparison states and Kansas and Tennessee questioned the reliability of one dataset used to assess turnout. GAO notes that any policy evaluation in a non-experimental setting cannot account for all unobserved factors that could potentially impact the results. However, GAO believes its methodology was robust and valid as, among other things, GAO's selection of treatment and comparison states controlled for factors that could significantly affect voter turnout, and GAO used three data sources it determined to be reliable to assess turnout effects.

Why GAO Did This Study

The authority to regulate U.S. elections is shared by federal, state, and local officials. Congress has addressed major functional areas in the voting process, such as voter registration. However, the responsibility for administration of state and federal elections resides at the state level. In 2002 Congress passed the Help America Vote Act (HAVA), which requires states to request ID from first time voters who register by mail, when they register to vote or cast a ballot for the first time, and to permit individuals to vote a provisional ballot if they do not have the requisite ID. Numerous states have enacted additional laws to address how an individual may register to vote or cast a ballot. As of June 2014, 33 states had enacted requirements for all eligible voters to show ID before casting a ballot at the polls on Election Day.

GAO was asked to review issues related to voter ID laws. This report reviews (1) what available literature indicates about voter ownership of and direct costs to obtain select IDs; (2) what available literature and (3) analyses of available data indicate about how, if at all, voter ID laws have affected turnout in select states; (4) to what extent provisional ballots were cast due to ID reasons in select states; and (5) what challenges may exist in using available information to estimate the incidence of in-person voter fraud.

GAO reviewed relevant literature to identify 10 studies that estimated selected ID ownership rates. GAO reviewed the studies' analyses and determined that these studies were sufficiently sound to support their results and conclusions. GAO also reviewed state statutes and websites to identify acceptable forms of voter ID in selected states and the price for certain forms of ID.

GAO also reviewed relevant literature and identified 10 other studies that estimated the effect of voter ID laws on turnout. GAO reviewed the studies’ design, implementation, and analyses, and determined that the studies weresufficiently sound to support their results and conclusions. Further, GAO compared turnout in two states—Kansas and Tennessee—that changed ID requirements from the 2008 to 2012 general elections with turnout in fourselected states—Alabama, Arkansas, Delaware, and Maine—that did not. GAO used a quasi-experimental approach, a type of policy evaluation that compares how an outcome changes over time in a treatment groupthat adopted a new policy, to a comparison group that did not make the same change. GAO selected states for evaluation that did not have other factors in their election environments that also may have affected turnout, such as significant changes to other election laws. GAO analyzed three sources of turnout data for the 2008 and 2012 general elections: (1) data on eligible voters, using official voter records compiled by the United States Elections Project at George Mason University, (2) data on registered voters, using state voter databases that were cleaned by a vendor through data-matching procedures to remove voters who had died or moved, and (3) data on registered voters, as reported to the Current Population Survey conducted by the U.S. Census Bureau.

GAO also analyzed data from Kansas and Tennessee election officials on the number of provisional ballots cast for ID reasons in the 2012 general election, and data from the Election Assistance Commission’s Election Administration and Voting Survey on the number of provisional ballots cast in select states in 2008 and 2012.

GAO reviewed relevant literature and identified 5 studies that attempted to identify instances of in-person voter fraud. GAO reviewed the studies’ analyses, and determined that these studies were sufficiently sound to support their results and conclusions. GAO also interviewed election officials in 46 states and the District of Columbia and officials from federal agencies that maintain federal crime data to determine how, if at all, instances of in-person voter fraud are tracked in state and federal databases.

For more information, contact Rebecca Gambler at (202) 512-8777 or or Nancy R. Kingsbury at (202) 512-2700 or

Reissued on February 27, 2015

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