MultipleVotingMethods,MultipleMobilizationOpportunities?

VotingBehavior,InstitutionalReform,andMobilizationStrategy

Christopher B. Mann University of Miami

Department of Political Science Assistant Professor

Genevieve Mayhew University of Maryland, College Park

Department of Political Science PhD Candidate

PreparedfortheUniversityofMarylandAmericanPoliticsWorkshop,February17,2012,CollegePark,Maryland.WewouldliketothankNickCarnes,MikeHanmer,PaulHerrnson,and the participants in the University of Marylands Center for American Politics andCitizenshipworkshop staffwhoprovidedvaluable feedbackon this project.Additionally,wewouldliketothanktheanonymouspartnerorganizationswhoallowedustodesignandimplement the field experiment as part of their voter contact programs. Without theirfundingforvotercontactandcooperationinimplementingtheexperiments,thisresearchwouldnothavebeenpossible. The views expressed in this paper are solely thoseof theauthors.Anyerrorsarealsothesoleresponsibilityoftheauthors.

MultipleVotingMethods,MultipleMobilizationOpportunities?

VotingBehavior,InstitutionalReform,andMobilizationStrategy

Abstract

The landscape of how votes are cast in the US has changed dramatically due to the growth of

voting by mail and early in person voting. These changes appear to confront voters with choices

about how to vote as well as whether to vote. They also appear to present voter mobilization

efforts with more opportunities to increase turnout. We use four field experiments to expand

understanding of voting behavior, gain insight on the voting reforms, and assess sequential

mobilization strategies. Sequential mobilization is the common practice of consecutively

attempting to mobilize citizens using each available method of voting (voting by mail, early in-

person voting, and Election Day voting). We found mobilization for the first method of voting

was successful (either voting by mail or early in-person voting), but sequential mobilization

attempts for later modes of voting did not generate a significant increase in turnout. Our findings

indicate that voters make a single decision about whether to vote and stick with it. That is

Americans behave as if they hold stable and consistent views about participation. The results

also indicate that voting reforms may offer more opportunities to increase turnout than skeptics

about pre-Election Day voting think but have much less impact on turnout than supporters hope.

Finally, sequential mobilization is wasteful since mobilization for later voting methods does not

generate additional turnout.

Reporters would ask, How did early voting change your strategy? It didnt change our strategy. It was our strategy. We sat down and said where early voting is no excuse, and convenient, we will begin the day that early votes start. [We engaged in] voter contact as though it was Election Day.

2

~ Jon Carson, Field Director of 2008 Obama Presidential campaign1

Election Day can be spread out over weeks. That means your get-out-the vote costs are more than ever.

~ Michael DuHaime, Political Director of 2008 McCain Presidential campaign2

People in most of the US no longer simply choose whether to vote, they also choose how,

when, and where to vote. The one dimensional calculus of voting has become multi-dimensional

through reforms allowing voters to choose no excuse voting by mail (a.k.a. absentee voting) or

early in person voting locations. However, the study of voting continues to primarily view

voting as a one dimensional decision about whether to participate and excluding the different

ways citizens may cast a ballot. When pre-Election Day voting is examined, it is usually treated

in isolation rather than as part of the sequence of options available to voters. This paper begins to

remedy this shortcoming in the literature by studying the decision to vote across the sequence of

voting opportunities from vote by mail, to early in-person voting, to Election Day voting.

Specifically, we use 4 large field experiments to study whether civic and political organizations

can increase turnout by mobilizing citizens across the sequence of voting methods. These results

provide new and important insights about voting behavior, institutional voting reforms, and

campaigns.

As the quotes above indicate, campaign professionals are attuned to the opportunities that

the pre-Election Day voting period provides to mobilize voters. Rather than mobilizing voters for

a singular Election Day, pre-Election Day voting allows political and civic organization to

contact potential voters multiple times to get out vote using different methods of voting. Multiple

voter contacts drives up the cost of voter mobilization efforts (Stein and McNeese 2009; 1 Quoted Jamieson (2009), pg 44. 2 Quoted in Nagourney (2008).

3Nordinger 2003), but campaign professionals across the political spectrum appear to see pre-

Election Day voting as an opportunity to increase turnout (e.g. Rove 2011; Nicholas 2008).

The landscape of how votes are cast in the US has undergone a radical metamorphosis in

the last dozen years. In the 2000 Presidential General Election, 16% of ballots were cast prior to

Election Day. By the 2008 Presidential General Elections, the share of ballots cast before

Election Day almost doubled to 29% and increased again to 32% in the 2010 Mid-term General

Election. Within states that allow pre-Election Day voting, the share of ballots cast before

Election Day is often much higher (Early Vote Information Center 2011). Thirty-three states

allow voters to cast ballots days or weeks before Election Day using no excuse voting by mail

(a.k.a. absentee voting) or early in person voting locations (National Conference of State

Legislatures 2011).

Support for these pre-Election Day voting reforms have been based heavily on the

convenience of voting by mail [VBM] and early in-person voting [EIPV] compared to

traditional Election Day voting at a precinct polling place.3 For example, supporters of the

federal Universal Right to Vote by Mail Act of 2009 [H.R. 2084] argue that [a]s our personal

and professional lives become busier and more demanding, too many of us do not have the

opportunity to make it to the polls on Election Day. Mail-in voting is more convenient for all

Americans And all citizens could calmly consider difficult choices on their ballots in the

privacy of their own home instead of under pressure of the confines of a polling booth,

(National Association of Letter Carriers 2011). Flexibility in the timing and location when using

VBM or EIPV is expected to lower the cost of voting, and the lower cost is in turn expected to

3 We focus on the voluntary no excuse voting by mail that is available in addition to traditional

precinct polling place voting (and early in person voting). Thus, voting by mail is distinct from

all mail elections (e.g. Oregon and Washington).

4increase participation in voting (Gronke et al 2008).

The transformation of the process of voting has implications for the understanding of

voting behavior. Pre-Election Day voting requires voters to make choices about what method of

voting to use, in addition to the long studied decision about whether to participate in voting. For

nearly a century following the adoption of the secret ballot in the early 1900s, questions about

when, where, and what method of voting to use were irrelevant abstractions in the study of

voting behavior since Americans had no choices about how to vote.4 However, the

transformation of voting in the US over the last dozen years has made how, when, and where to

voter relevant questions to voters and voter mobilization efforts and should make these

questions important to scholars.

This paper examines the full process of deciding whether and how to vote when multiple

methods of voting are allowed. We present four large scale field experiments that measure civic

and political organizations common practice of attempting to mobilize the same voters for

different methods of voting in a particular election. We refer to the practice of attempting to

mobilize citizens to vote using each mode of voting as it arises sequentially in the election

calendar as sequential mobilization. Recruitment for VBM comes first because any citizen can

request a mail ballot months before the election. EIPV is second because it provides the

opportunity to vote in-person at an official voting location for one or more weeks prior to

Election Day (the EIPV period varies by state). Anyone who was not recruited to use VBM can

4 Absentee voting was first instituted to allow Union soldiers to vote during the 1864 elections

during the Civil War. It has long been available in most jurisdictions for members of the military,

students, and ill or infirm voters who meet one of the legally proscribed set of excuses for being

unable to make it to the polls on Election Day. However, the use of excused absentee voting

was very small and remains so in states still requiring an excuse for absentee voting.

5be encouraged to vote during the extended in-person voting period. Election Day is the final

opportunity to change a non-voters mind about participating in the election.

In addition to providing insights about voting behavior, these experiments provide

insights on the effect of institutional voting reforms. The experiments do not directly measure the

effect of instituting voting reforms since it is impossible to randomly assign voting rules. Instead,

the treatments measure the effect of reforms as individuals learn about them. Since many citizens

are unaware of how to vote using VBM and EIPV, the treatments encouraging and explaining

these alternative methods make these reforms a reality for the treated voters. Thus, the impact of

the treatments can be interpreted as the effect of institutional reforms.

The four field experiments conducted in Maryland, Idaho, Ohio, and North Carolina

during the 2010 General Election assess treatments with different combinations of mobilization

for voting by mail, early in-person voting, and Election Day voting. The consistent results across

all four experiments have important implications for voting behavior, voting reforms, and

campaign practice. We find statistically significant increases in turnout from mobilizing citizens

for the first method of voting (VBM in Experiments 1-3 and EIPV in Experiment 4). However,

we find no additional increases in turnout from mobilization for subsequent modes of voting.

We make contributions to the study of voting behavior, institutional voting reforms, and

election strategy. First, from a behavioral perspective, our findings indicate that voters make a

single decision about whether to vote and stick with it. Additional communication later in the

election about additional methods of voting does provoke a reconsideration of this decision. In

short, our findings support the proposition that Americans behave as if they hold stable and

consistent views about participation, at least in the context of a particular election. Second,

although instituting reform does not appear to increase turnout on its own, voting reforms do

6appear to create new opportunities to increase participation when citizens become aware of how

to use pre-Election Day voting. On the other hand the impact of reform should not be overstated,

since new methods of voting appear to create alternative opportunities for voting (and

mobilization) rather than additional opportunities as supporters of reform expect. Third, the

increase in turnout using mobilization for VBM and EIPV replicates the findings of other field

experiments that studied these mobilization tactics in isolation. Finally, the results suggest that

civic and political organizations should not pursue sequential mobilization strategies.

The paper proceeds as follows: The next section of the paper discusses how sequential

mobilization expands existing research on voting behavior. Section 3 explains how sequential

mobilization provides insights into the effects of election reform. Section 4 describes the logic

behind why civic and political organizations often use sequential mobilization strategies. Section

5 describes the research design and methodology of the four field experiments. Section 6 details

each experiment and its findings. Section 7 discusses the results before we conclude in Section 8.

2. Sequential Mobilization and Voting Behavior

It is well established that communication from civic and political organizations plays an

important part in shaping individual decisions about whether to vote. Rosenstone and Hansen

(1993) attribute the decline in US voting participation in the late 20th Century to the decline of

mass political parties that repeatedly interacted with citizens. The field experiments literature on

voter mobilization has demonstrated that mobilization efforts by civic and political organizations

can significantly boost voter turnout. However, the field experiments literature also shows that

some commonly used voter mobilization tactics have little or no effect (for recent reviews see

Green and Gerber 2008; Michelson and Nickerson 2011). Our goal is to find out whether

7sequential mobilization is effective at increasing participation and what the answer means for

understanding voting behavior.

The availability of pre-Election Day voting provides civic and political organizations

with more opportunities to mobilize voters. Civic and political organizations have historically

been concentrated mobilization efforts in the final days before Election Day, and evidence from

field experiments supports this practice because treatments close to Election Day are generally

more effective than earlier communication (Nickerson 2007; Green & Gerber 2008 pg.143; c.f.

Panagopolous 2011b). However, pre-Election Day voting means the traditional mobilization

opportunity of Election Day is stretched over many weeks.

Civic and political organizations can mobilize voters by encouraging pre-Election Day

voting. Recent field experiments show that encouraging EIPV increases overall turnout and is as

good an opportunity to do so as Election Day voting. A comparison of EIPV mobilization and

Election Day mobilization using the same mobilization message found an equal impact on voter

turnout through each mode of voting (Mann 2012). A series of large scale field experiments

found that treatments to recruit voters to request a mail ballot consistently generated a

statistically significant increase in turnout. These experiments were conducted in multiple types

of elections from 2006 through 2010 by a variety of civic and political organization (Mann 2011;

Mann & Mayhew 2011). It is notable that the VBM recruitment treatments are most effective

when focusing on information about how to vote by mail rather than relying on the psychological

mechanisms that drive successful mobilization on Election Day (e.g. Green and Gerber 2008,

82010; Mann 2010).5

One important shortcoming of the recent field experiments on mobilization using VBM

and EIPV and the larger field experimental literature on mobilization for Election Day voting is

studying each mode of voting in isolation. The main question in examining sequential

mobilization is whether citizens in jurisdictions where multiple methods of voting are allowed

make decisions about each mode of voting separately or make one decision about whether to

vote and then decide how to vote. The success of sequential mobilization depends on how the

availability multiple methods of voting shape the process of deciding whether to vote. The key

issue is the order in which citizens make decisions about whether to vote and how to vote. Do

citizens decide whether to vote, and then choose among alternative modes of voting? In this case,

encouragement to use later modes of voting in sequential mobilization strategies will have little

or no effect. Alternatively, citizens may consider the merits of each method of voting then decide

whether they will use this method of voting. If citizens make a new decision about whether to

vote each time a different method of voting becomes available during the election cycle then

each mode provides a new opportunity to get citizens to vote. The new decision for each mode of

voting can be conceived of either as a quasi-independent decision on the merits of each method

or as a moment in a cumulative decision function when potential use of a different method of

voting is added.6

5 In all mail elections, reminders to return the ballots with a robo call from the local election

office or face-to-face canvassing by a civic organization increased turnout (Mann and

Sondheimer 2009; Arceneaux, Kousser & Mullin 2011). 6 One prominent critique of pre-Election Day voting is that voters will make ballot choices

without full information (e.g. Meredith and Malhotra 2011), so the decisions about voting at

9

Whatever the exact nature of the decision process, the key question for sequential

mobilization is whether the availability of a different mode can be leveraged as the catalyst for a

fresh consideration of whether to turn out. Mobilization for sequential modes of voting assumes

voters can be prompted to make a new decision about participating when encouraged to use each

method of voting, and therefore mobilization for each mode of voting will generate an additional

increase in turnout. If citizens make one decision about whether to vote, and then choose among

methods of voting as secondary decision, sequential mobilization will not work.

The question of whether multiple methods of voting add times for new decisions about

whether to vote or simply shifts a single decision to a different time echoes a long-standing

division in the understanding of political behavior. The Columbia School observes that most

citizens make up their minds about voting in advance of Election Day and once they make this

decision they are not influenced by communication during the election (e.g. Lazarsfeld, Berelson

& Gaudet 1948; Berelson, Lazarsfeld & McPhee 1954). The proposition that citizens will make

one decision about whether to vote when prompted by mobilization for the first method of voting

and will not reconsider when mobilized for other modes is consistent with the Columbia School

view of voting behavior. On the other hand, the Michigan School finds little evidence that

Americans have stable positions about politics and that political views can be influenced by the

flow of information citizens receive from political elites (e.g. Campbell, Converse, Miller &

Stokes 1960; Converse 1964; Lewis-Beck, Jacoby, Norpoth and Weisberg 2008; Zaller 1992).

The expectation that sequential mobilization will prompt new decisions about voting for each

method is consistent with the Michigan Schools perspective that citizens are susceptible to

different times may also depend on factors that change over time other than the different costs to

cast a ballot be each subsequent method of voting.

10influence because they do not have lasting political dispositions.

3. Insights on Voting Reform from Sequential Mobilization Experiments

Communication by civic and political organizations is as vital to information citizens

about elections as it is to shaping their behavior. We contend that this central role in informing

voters about the political world means that our experiments provide unusual and valuable

insights about the effect of voting reforms. Although it is impossible to randomly assign the rules

under which individuals vote, we can randomly assigned treatments that will make many citizens

aware of alternative methods of voting for the first time. Since the American public generally has

low levels of political knowledge for making voting choices (e.g. Campbell, Converse, Miller &

Stokes 1960; Popkin 1991; Zaller 1992), it seems reasonable to assume that citizens with

moderate and low probability of voting are unlikely to be sufficiently informed about VBM and

EIPV reforms that are esoteric to their daily lives to vote using these methods.

Under the assumption that voters lack information about reforms, our treatments that

encourage voters to use VBM or EIPV create these reforms for the citizens who would

otherwise not know about them. In a world where citizens have perfect information about voting

procedures, the effect of reform on behavior occurs immediately when reforms were instituted.

In a more realistic context, the effect of reforms is attenuated to the degree voters remain

unaware of the reforms. As a tool for understanding the impact of election reforms, the

treatments in our experiments are a randomized intervention that allows measurement of the

causal effects of informing citizens about pre-Election Day voting reforms. If informing citizens

about the reforms does not increase turnout, then it seems reasonable to conclude that the

reforms will have less impact when citizens likely to be unaware of the reforms. This indirect

11measurement of reforms through randomly altering citizens information levels gets around the

build it and they will come assumption that is all too common in observational studies about

the effects of voting reforms (c.f. Stein, Owens and Leighley 2003).

Although the measurement of effects of voting reforms may be indirect, the insights

about voting reform are important because the experimental methodology avoids the problems of

endogeneity and unobserved heterogeneity across jurisdictions and election years that plague

observational studies of election reform that rely on a small number of observations and

aggregate statistics about voting (Hanmer 2009).

A large observational literature on VBM and EIPV reforms finds little or no evidence that

allowing voters choices among these forms of voting increases turnout (Burden et al 2009;

Kropf, Parry, Barth & Jones 2008; Gronke, Galanes-Rosenbaum, Miller and Toffey 2008;

Gronke, Galanes-Rosenbaum and Miller 2007; Berinsky 2005; Fitzgerald 2005; Hanmer and

Traugott 2004; Karp and Banducci 2001; Berinsky, Burns, Traugott 2001; Neely and Richardson

2001; Stein 1998; Stein and Garcia-Monet 1997; Oliver 1996; Patterson & Caldeira 1985).7

Indeed, several scholars come to the conclusion that the most noteworthy effect of these reforms

is to make voting more convenient for people who would already vote (e.g. Berinsky 2005;

Burden et al 2009). However, the recent field experiments showing that VBM recruitment and

encouragement to use EIPV increase turnout support the proposition that these treatments inform

voters about how to use these methods of voting. The increase in turnout in these experiments

appears to be driven by the specific information provide about how to vote (Mann 2011; Mann

2012).

7 Other research has examined the effect of instituting all mail voting with similar conclusions

about the lack of effect on turnout. We do not address this literature because all mail elections

and voluntary no-excuse voting by mail are radically different.

12

The question about voting reforms that is addressed for the first time in these four

sequential mobilization experiments is whether allowing multiple modes of voting creates more

opportunities when citizens decide to vote or simply more choices for people who have already

decided to vote. Supporters of VBM and EIPV reforms often argue that creating more options for

voting will increase turnout by allowing citizens to choose a method of voting that best suits

them. This argument implies citizens will weigh costs and benefits separately for each method of

voting. If this belief about separate decision for each method of voting is correct, then

(awareness of) more methods of voting will generate an increase in turnout. On the other hand, it

is possible pre-Election Day voting reforms merely create alternative, earlier times at which

citizens make the decision about whether to vote. That is, allowing pre-Election Day voting may

shift the timing of a voters decision about whether to vote (and the method used to vote), but

will not to an increase in turnout.

4. Why Do Campaigns Use Sequential Mobilization?

When confronted with people who were unresponsive to attempts to mobilize them for an

early method of voting, a voter mobilization organization must decide whether to cease their

efforts or to try again to mobilize the same people to use another later mode of voting. There are

several reasons that civic and political organizations often follow the latter course of if at first

you dont succeed, try, try again.

Voter mobilization programs are aimed at increasing the participation of a particular set

of citizens in pursuit of civic, policy, or political goals. Therefore, from an organizations

perspective, deciding to stop mobilization efforts is less than satisfactory when additional

communication might increase turnout. Nor does the possibility of shifting focus to mobilize

13other people make ceasing efforts to mobilize the first targets more attractive because the second

group is by definition a lower priority on one or more dimensions of interest to the

organization.

Second, parallels to a number of other behaviors suggest that sequential mobilization will

be effective. Research on a wide range of behavior has demonstrated that repeated

communication increases the chances of getting the desired outcome. For example, consumer

choice is influenced by repeated advertising. Public health programs use repeated interventions

to reduce unhealthy behavior. Similarly, programs encouraging socially desirable behavior such

as recycling also use repeat communication to successfully influence behavior (Cialdini 2009).

Perhaps most familiar to political professionals, survey researchers routinely use multiple

contacts to increase survey participation (e.g. Atkeson et al 2011; Peytchev, Baxter & Carley-

Baxter 2009; Mann 2005).

Third, the organizational decision to use sequential mobilization is frequently made when

resources become available late in the election cycle. By this point, organizations often have

deep commitments to plans and/or stretched too thin to undertake the necessary planning efforts

to identify new targets for mobilization.

5.1. Research Design

To test whether sequential mobilization is effective, we present four field experiments

conducted during the 2010 General Election using various combinations of sequential voting

treatments (detailed below). These experiments were conducted in partnership with a network of

14nonpartisan charitable 501(c)3 civic organizations.8 Since the experiments were embedded in our

partner organizations mobilization efforts in 2010, each experiment meets Gerber and Greens

four criteria for an ideal field experiment: (1) whether the treatment used in the study

resembles the intervention of interest in the world, (2) whether the participants resemble the

actors who ordinarily encounter these interventions, (3) whether the context within which

subjects receive the treatment resembles the context of interest, and (4) whether the outcome

measures resemble the actual outcomes of theoretical or practical interest (Gerber & Green

2011; Chapter 2).

The design of these four field experiments resembles actual voter mobilization efforts in

a fifth way: Each experiment was initially designed to measure the effect of mobilization using

the first method of voting: i.e. recruitment to vote by mail in Experiments 1-3 and

encouragement to vote early in-person in Experiment 4. However, the initial designs were

revised to become sequential mobilization programs when our partner organizations received

additional resources to invest in voter mobilization. Therefore, we revised the experimental

designs to randomly assign sequential mobilization treatments for later modes of voting to a

subset of the original treatment group. We developed the design and did the random assignments

for each treatment in the four experiments.9

8 Our agreement with these organizations specified unrestricted publication rights using the data

from this experiment, thus avoiding the potential for selection bias in reported results when

organizations control the release of information (Nickerson 2011; Gerber 2011). 9 Although we offered advice on best practices from existing research, the decisions to conduct

these voter mobilization programs, the decisions about which voters to contact, and the content

of the actual treatments were made by our partner organizations.

155.1.1. Subjects

Selectionofthesubjectpopulationwasperformedbyourpartnerorganizations.Allfourexperimentsusethesamebasicselectionparameters,butExperiments3and4includeadditionalvoters.Thecommonselectionparameters:(1)Registeredvoterswithastrongmatchbetweenphonelistingsandvoterfilerecords,accordingtoCatalistLLC,aconsumerdatafirmspecializingininformationonregisteredvoters;10(2)Registeredvoterswithapredictedprobabilityofvotingbetween30%and70%,basedonapredictivevoterturnoutmodelprovidedbyCatalistLLC.Thiscriterionwasbasedonpreviousresearchthatvotermobilizationcontactshavemaximumimpactforregisteredvoterswitha5050chanceofturningout(GreenandGerber2008p.174;ArceneauxandNickerson2009b;Parryetal.2008;Hillygus2005;Niven2004).(3)RegisteredvoterswithalikelihoodofrespondingtoVBMRecruitmentgreaterthan3.5%,basedonapredictiveVBMrecruitmentresponsemodelprovidedbyanothernonpartisancharitable501(c)3organization;(4)Registeredvotersexpectedtotrustinformationaboutpoliticalissuesfromourpartnerorganization,basedonaproprietarymicrotargetingmodel(FigureS1intheSupplementalMaterialsonlineillustratesthisprocess).Experiments3and4alsotargetedvoterswhoweremembersoftheorganizationoritsallies,votersyoungerthan30,nonwhitevoters,andunmarriedwomen.

Ourpartnerorganizationsselectionparametersdrawattentiontothequestionofexternalvalidity.Theresultsfromallfieldexperimentsarenecessarilyspecifictothe10 In practice, the strong match usually means a match of address and full name. Medium and

weak match phone numbers include records that match only on address and last name, address

only, etc. The standard practice of our partner organization, based on extensive experience with

voter contact phone calls, was to use only strong match phone numbers.

16contextinwhichtheyareconducted,andoursarenodifferent.Theopportunitiestoconducttheseexperimentsinapartnershipmakesitmorerealisticintermsofwhatcivicorganizationsactuallydo,butthismeansoursubjectsarenotperfectlyrepresentativeofallregisteredvoters.Nonetheless,thedemographicprofilesofeachexperimentinTable1,3,5and7showthatourstudypopulationsaresufficientlydiversetoprovidevaluableinsightsaboutvotingbehavioracrossalargeportionoftheAmericanelectorate.

5.2. Methodology

The effect of the treatments is measured using publicly available individual voter turnout

records acquired after the 2010 General Election by Catalist LLC. Catalist also collects data from

state and local election officials to track the mode of voting used by each individual who cast a

ballot in the 2010 General Election. Thus, the vote history data from Catalist allows us to

measure the effects on each mode of voting as well as upon overall turnout.11

Since the random assignment for three of the four experiments is clustered by household,

we regress individual level 2010 voting behavior on the assignment to treatment in order to

estimate the average treatment effect [ATE] and robust clustered standard errors that are adjusted

for the clustering of random assignment by unique address (Arceneaux 2005; Arceneaux and

Nickerson 2009a; Green and Vavreck 2008). We also take advantage of increases in efficiency

11 Voters who did not appear on the post-election voter rolls were coded as non-voters. We

cannot exclude voters who drop from the voter rolls because the administrative process for

removing a record from the voter rolls is conditional on non-voting under the federal National

Voter Registration Act of 1993. If the treatment increases turnout, it makes voters more likely to

remain on the rolls. Thus, exclusion of non-voters from both the treatment and control groups

will bias the estimate of the treatment effect.

17of the ATE estimate when covariates are included in the regression model. The inclusion of

covariates is unnecessary to obtain unbiased estimates of the ATE in a randomized experiment,

but including covariates reduces the disturbance variance. In the results below, we refer to the

more efficient model including covariates. Since these experiments have large populations and

the randomizations are well balanced (see Tables 1, 3,5 and 7), including covariates has a

substantively trivial impact on the estimates of the ATE. Finally, it should be noted that we

report only intent to treat effects, because it is not possible to measure who reads the mail

treatments to calculate average treatment among the treated effects.

We report the effects for each mode of voting as a percentage of all voters in the

experiment rather than as the share of ballots cast. Using all voters as the denominator for each

mode of voting allows us to treat the turnout for each mode additively. Thus, if use of one mode

increases in the treatment group, there must be a corresponding increase in turnout, decline in

use of another mode, or both.

For hypothesis testing about the effect on turnout and the mode of voting for the initial

mobilization, we use a one-tailed significance test. A one-tailed test is appropriate because there

is no theoretical expectation that the treatments could reduce turnout or use of the initial mode of

voting. For hypothesis testing about the sequential modes of voting, we apply a two-sided

significance test, because we could see positive or negative effects on these modes of voting.12

12 Strictly speaking, we have no expectation of a positive impact on later modes of voting when

the assigned treatment only attempted to contact someone for the first mode of voting. However,

we apply a two-sided significance test to later modes of voting in these treatment conditions for

consistency across treatments since this is a more conservative standard for statistical

significance. None of our substantive interpretations would change with the looser standard of a

one-tailed test.

18The contact for the first mode of voting may decrease the use of later modes of voting by shifting

citizens to the earlier mode of voting, but the contacts encouraging later modes of voting are

expected to increase the use of the later modes in order to increase turnout.

Since voters who had already cast a ballot could not be influenced by our treatments, we

obtained the list of voters who had cast ballots prior to the EIPV and Election Day voting

treatments and excluded these voters from attempted contact.13 To preserve the unbiased

estimate of treatment effects, we analyze the results using the treatment condition from the

original random assignment, even if the sequential mobilization contacts were not attempted

because an individual had already voted.

6.1. Experiment 1 (Maryland)

Experiment 1 tests the effects of four combinations of treatments for sequential

mobilization: 1) VBM Recruitment only, 2) VBM Recruitment plus Early in Person Voting

GOTV call, 3) VBM Recruitment plus Election Day GOTV call, and 4) VBM Recruitment plus

Early in Person Voting GOTV call plus Election Day GOTV call. The experiment was

conducted in Maryland during the 2010 General Election.14

The VBM Recruitment treatment was a single mailer sent to arrive about a month prior to

Election Day [September 30- October 5]. The mailing contained information about voting by

mail, instructions on how to request a mail ballot, an official application to request a mail ballot,

13 The exclusions of absentee, mail, and early in-person voters were based on data obtained daily

from state and local election officials by Catalist LLC. 14 In addition to the criteria noted above, our partner organization in Maryland removed a small

number of voters from the experimental population prior to randomization because they lived in

areas where other voter contact programs were planned.

19and a return envelope pre-addressed to the county elections office. The EIPV treatment was a

live phone call made at the beginning of the early in-person voting period by a commercial call

center [Oct. 20-Oct. 25]. The Election Day treatment was a live phone call made during the

weekend before Election Day by the same commercial call center [Oct. 29-Nov. 1].The scripts

for both phone calls utilized the plan making script shown to be successful at increasing

turnout by Nickerson and Rogers (2010). In addition, the same Election Day mobilization calls

were found to be effective at increasing turnout in a field experiment conducted in other states

(Mann & Klofstad n.d.). The EIPV call also provided a list of EIPV vote centers near the voter.

(Copies of mailings and phone scripts are in the Supplemental Materials available online).

Random assignment was done at the household level, so that all voters at the same

address were assigned to the same condition. There were a total of 85,566 households (96,570

voters). Table 1 shows the quantities assigned to each condition and that the random assignment

were well balanced for observable covariates about age, gender, race, and past voting in the last

three general elections.

Results:

The effectiveness of VBM Recruitment saw an increase in turnout. This is to be expected

considering these results have been established in other work (Mann 2011). As expected, each of

the treatments generated a statistically significant increase in turnout above the control groups

42.4% turnout. Table 2 reports the average treatment effect and robust clustered standard errors

as change in probability. Column (a) reports the effect of the four assigned treatments on turnout

without covariates. Column (b) adds covariates to the model. As noted above, we focus on

Column (b), since the estimates of ATEs are (slightly) more efficient when covariates are

20included. The VBM Recruitment treatment generated an increase in turnout of 1.9 percentage

points (p=0.001). The VBM Recruitment plus Early in Person Voting GOTV call treatment

increased turnout by 1.2 percentage points (p=0.001). The VBM Recruitment plus Election Day

GOTV call treatment also increased turnout by 1.2 percentage points (p=0.001). The VBM

Recruitment plus Early in Person Voting GOTV call plus Election Day GOTV call treatment

increased turnout by 1.6 percentage points (p=0.006).

We are most interested in the marginal effect of adding mobilization for sequential modes

of voting, but we find no evidence of a marginal effect in Experiment 1. The initial VBM

treatment in each condition is generating all of the increase in turnout with no marginal effect

from contacts aimed at later modes of voting. An F-test comparing the estimated ATEs for the

four treatments demonstrates that the magnitudes of the effects from the four treatment

conditions are statistically indistinguishable from one another (p=0.321). Furthermore, no pair-

wise comparison reveals a statistically significant difference.

The increase in turnout from VBM recruitment is consistent with the effects found by

experiments that examined this mobilization tactic in isolation (Mann 2011; Mann & Mayhew

2011.). However, the absence of any effect from the live phone calls to mobilize voters for

Election Day voting is inconsistent with other experiments using this treatment in isolation

(Nickerson & Rogers 2010; Mann & Klofstad n.d.).

Columns (c) and (d) of Table 2 report the effects the use of voting by mail (with and

without covariates in the model, respectively). The option to vote by mail without an excuse was

relatively new in Maryland in the 2010 election,15 so only 2.2% of the control group used a mail

15 Maryland voters had the option of no-excuse VBM in 2006 but it was struck down as

unconstitutional by the states Supreme Court and abolished for the 2008 election. Following

21ballot. Each of the treatments nearly tripled the use of voting by mail, with statistically

significant effects between 4.0 and 4.3 percentage points. As above, the effect of the treatments

on voting by mail across the four treatment conditions is statistically indistinguishable (p=0.589).

Since this increase in voting by mail is larger than the increase in turnout, the treatments are

causing voters to cast ballots by mail who would otherwise vote early in-person voting or vote on

Election Day.

Columns (e) and (f) of Table 2 report the effects of the treatments on early in-person

voting (with and without covariates in the model, respectively). The treatments cause a

statistically significant decline in the use of early in-person voting. The shift from EIPV to VBM

is between 1.0 and 1.4 percentage points. There is some evidence of a marginal effect from the

EIPV calls on use of EIPV, but only as a shift from Election Day voting to EIPV. Both treatment

conditions including an EIPV call have slightly smaller reductions in EIPV use than the other

two treatment conditions without an EIPV call. The effects on EIPV from the EIPV call do not

appear to be equal across the four treatments (p=0.059), and pair-wise comparisons indicate that

the EIPV call accounts for the difference. Since the increase in VBM use is nearly identical

across the treatment conditions, the EIPV calls appear to cause a shift to EIPV among voters who

would otherwise cast ballots on Election Day.

Columns (g) and (h) of Table 2 report the treatment effects on Election Day voting (with

and without covariates in the model, respectively). As expected, all of the treatments shifted a

significant portion of voters from traditional Election Day voting to other modes of voting. The

decline in Election Day voting was between 1.0 and 1.9 percentage points, although the

passage of a Constitutional Amendment with 72% of the vote in the 2008 election, no-excuse

VBM was reinstated in Maryland for the 2010.

22differences across the treatments are not statistically significant (p=0.196).

6.2. Experiment 2 (Idaho and Ohio)

The primary distinctions between Experiments1 and 2 are the omission of the EIPV-

related treatments and the different locations (Maryland vs. Idaho and Ohio). The treatments

were (1) VBM Recruitment only and (2) VBM Recruitment plus Election Day Phone Call.16

Many observers of American politics would consider Idaho and Ohio to be strange political

bedfellows. However, we pool the results based on identical treatments arising from our partner

organizations decisions about sequential mobilization. When we separate the states, we see no

significant differences between them. The details of this heterogeneity analysis by state are in the

Supplemental Materials available online.

In Experiment 2, random assignment was done at the household level. There were a total

of 72,007 households (77,921 individuals). Table 3 shows the quantities assigned to each

condition and that the random assignment was well balanced for observable covariates about age,

gender, race, and past voting in the previous three general elections.

Results:

Table 4 reports results of Experiment 2 in the same format at Table 2. In Column (b),

each of the treatments generated a statistically significant increase in overall turnout above the

42.8% turnout in the control group. The VBM Recruitment treatment generated an increase in

turnout of 2.1 percentage points (p=0.001) when it was the sole attempt to contact voters. The

16 The Election Day phone calls in Experiments 2-4 use the same script as Experiment 1, but

were randomly assigned to one of four call centers (including the one used in Experiment 1) as

part of a field experiment on call center efficacy (see Mann & Klofstad n.d. for details).

23VBM Recruitment plus Election Day phone call treatment generated an increase in turnout of 2.7

percentage points (p=0.001). The 0.6 percentage point increase in turnout from the call made on

the weekend prior to Election Day is a marginally statistically significant effect (F-test

comparing effects for turnout: p=0.105). We return to this apparent increase from sequential

mobilization after reviewing the effects on mode of voting in Experiment 2.

The treatments generated a statistically significant increase in the use of voting by mail of

3.9 and 4.3 percentage points, respectively (Table 4, col. (d)). Since this increase in voting by

mail is larger than the increase in turnout, it indicates the treatments are again causing voters to

cast ballots by mail who would otherwise vote early in-person or vote on Election Day. As with

overall turnout, the effect of VBM Recruitment plus Election Day phone call treatment on

turnout using VBM appears to be slightly larger (F-test comparing effects for VBM: p=0.115).

Less than one percent of all the voters used EIPV, so it is unsurprising that there is no

statistically significant effect in the use of EIPV (Table 4, col. (f)). As expected, both treatments

shifted a significant portion of voters away from Election Day voting to VBM. The decline in

Election Day voting was 1.8 and 1.6 percentage points, respectively (Table 4, col. (h)), and the

differences between the treatments are not statistically significant (p=0.566).

Though we stretch the conventional standards to identify marginally significant effects

from the calls made on the weekend before Election Day, the apparent marginal effect on turnout

still does not support the logic of sequential mobilization. The phone calls before Election Day

increase turnout in large part by prompting an increase in voting by mail rather than Election

Day voting: Our experiment estimates that VBM use increases by 0.4 percentage points, while

Election Day voting increases by only 0.2 percentage points. In short, Election Day voting does

not seem to be providing another opportunity to mobilize citizens to vote; instead, phone contact

24as Election Day approaches is efficacious primarily as a reminder to return a mail ballot.

6.3. Experiment 3 (North Carolina I)

Experiment 3 tests the effects of two combinations of treatments for sequential

mobilization: 1) VBM Recruitment only, 2) VBM Recruitment plus EIPV Mailing plus Election

Day phone call. It was conducted in select counties in North Carolina during the 2010 General

Election.

The VBM Recruitment treatment in Experiment 3 was a sequence of contacts: a robo call

and a mailer with a Thank You for Voting social pressure message (Panagopoulos 2011a), a

robo call with pre-notification about the VBM application mailer, and the mailer containing an

application and instructions to request a mail ballot.17 (See Supplemental Materials online for

timeline of contacts and copies of the mailings and scripts.) The EIPV treatment was a mailer

sent with information on using VBM, EIPV and Election Day voting. Finally, the same live

phone call as Experiments 1 and 2 was made the weekend before Election Day.

In addition to the criteria described above, subjects were selected using three additional

criteria. First, only registered voters in Buncombe, Cumberland, Forsyth, Guilford, Mecklenburg,

New Hanover, Pitt and Wake counties were selected. Second, only voters who had voted in the

2008 General Election were selected, because of the thank you for voting in 2008 element of

the treatments. Third, households with more than one targeted voter were excluded. A total of

84,000 voters were selected. Table 5 shows the quantities assigned to each condition and that the

17 North Carolinas unusual process for requesting to vote by mail requires the voter to hand-

write the request for a mail ballot. Thus, the North Carolina VBM Recruitment mailer has a

blank page as the application accompanies by detailed instructions on what to write, rather

than the application form in the VBM Recruitment mailer in Experiments 1 & 2.

25random assignment was well balanced for observable covariates about age, gender, race, and past

voting in the previous three general elections.

Results:

As in Experiment 1, the VBM Recruitment treatment generated a significant increase in

turnout, but there is no marginal increase in turnout from the mobilization for later modes of

voting. Table 6 reports the results in the same format as Tables 2 & 4, except that no clustering

of standard errors is required, because only single-voter households are included. Both

treatments generated a statistically significant increase in turnout above the 33.7% turnout in the

control group. The VBM recruitment treatment generated an increase in turnout of 1.8

percentage points (p=0.001). The VBM Recruitment, EIPV and Election Day phone treatment

generated an increase in turnout of 1.5 percentage points (p=0.001). An F-test comparing the

estimated ATEs for the two treatments demonstrates that the magnitudes of the effects from the

two treatment conditions are statistically indistinguishable from one another (p=0.575).

The effect of the treatments on voting by mail (~3.5 percentage points) (Table 6, col (d))

is statistically indistinguishable (p=0.429). Since the increase in voting by mail is larger than the

increase in turnout, the treatments again are causing voters to cast ballots by mail who would

otherwise vote early in-person voting or vote on Election Day. The shift from EIPV to VBM is

0.4 and 0.5 percentage points, respectively (Table 6, col (f)). The decline in Election Day voting

was 1.3 and 1.7 percentage points, respectively (Table 6, col (g)), although the differences across

the treatments are not statistically significant (p=0.346).

266.4. Experiment 4 (North Carolina II)

Experiment 4 is different from the previous experiments because it begins with EIPV

rather than VBM in the sequence of voting modes. Experiment 4 tests the effects of two

combinations of treatments for sequential mobilization: 1) EIPV Mail and Phone Call and 2)

EIPV Mail and Phone Call plus Election Day Phone Call. The EIPV treatment included a

mailing providing information about up to four EIPV vote centers in the voters county and a

phone call with an implementation script (Nickerson & Rogers 2010) similar to the EIPV script

in Experiment 1 and the Election Day Phone calls. (A timeline of contacts and copies of the

EIPV mailing and phone script are in the Supplemental Materials online.) The Election Day

phone call treatment was the same used in the prior experiments.

The subjects for Experiment 4 were selected using the same criteria as Experiment 3

except: voters who had requested a mail ballot prior to the experiment were excluded, multi-

voter households were not excluded, the vote-by-mail responsiveness predictive model was not

applied, and a different set of counties in North Carolina was targeted (Alamance, Cabarrus,

Catawba, Davidson, Gaston, Iredell, Johnston, Onslow, Randolph, Robeson, Bowan, Union, and

Wayne).

In Experiment 4, randomization was done at the household level. There were a total of

45,527 households (47,875 individuals). Table 7 shows the quantities assigned to each condition

and that the random assignment was well balanced for observable covariates about age, gender,

race, and past voting in the previous three general elections.

Results

Table 8 follows the format of Tables 2 & 4, including the use of robust clustered standard

27errors to account for household level random assignment. In Column (b), the EIPV Mail

treatment generated a marginally significant increase in turnout of 0.8 percentage points

(p=0.084) above the 35.3% turnout in the control group. The EIPV Mail and Election Day phone

call treatment was essentially indistinguishable: 0.7 percentage point increase in turnout

(p=0.116), with p=0.832 from an F-test comparing the estimated ATEs. Thus, there is no

evidence of a marginal effect of adding mobilization for Election Day voting. Although the EIPV

treatment generates a smaller increase as the initial mode of mobilization than VBM Recruitment

in Experiments 1-3, it again appears that the initial treatment in each condition is generating all

of the increase in turnout, with no marginal effect from mobilization for later modes.

Column (d) reports no effect on voting by mail. This was expected, since the treatments

were focused on EIPV and Election Day voting. Both treatments increased early voting, with

statistically significant effects of 1.5 and 1.2 percentage points, respectively (Table 8, col. (f.)).

This small difference is not significant (p=0.318). The effects on Election Day voting are not

statistically significant, although both effects are negatively signed, as expected: The increase in

EIPV was larger than the increase in turnout, which requires that the treatments shifted voters

from Election Day voting to EIPV.

7. Discussion

In four large scale field experiments conducted in Idaho, Maryland, Ohio, and North

Carolina, we found mobilization for the first method of voting was successful, but sequential

mobilization attempts for later modes of voting did not generate a significant increase in turnout.

In Experiments 1-3, there was a strong increase in turnout from the VBM recruitment treatment

but no additional increase from attempts to mobilize voters for EIPV or Election Day voting. In

28Experiment 4, the initial mobilization for EIPV appeared to generate a modest increase in

turnout, but again there was no additional increase from the attempt to mobilize voters for

Election Day voting.

Although Experiment 3 initially hinted at successful sequential mobilization with phone

calls prior to Election Day, detailed examination revealed that these calls served as a reminder to

return mail ballots rather than mobilize voters for Election Day voting. The calls functioned as a

follow-up to the VBM recruitment treatment, rather than sequential mobilization for a later

method of voting.

The increases in turnout from mobilization for the initial method of voting replicate the

findings of other field experiments: The increases in turnout from VBM recruitment in

Experiments 1-3 are consistent with the effects found by experiments that examined this

mobilization tactic in isolation (Mann 2011; Mann & Mayhew 2011). The increase in turnout

from encouragement to use EIPV in Experiment 4 is consistent with other experiments using

similar treatments (Mann 2012). The absence of any effect from the live phone calls as a

sequential mobilization tactic for Election Day voting is notable because this is inconsistent with

the successful mobilization in both past and contemporaneous experiments using this treatment

outside of a sequential mobilization setting (Nickerson & Rogers 2010; Mann & Klofstad n.d.).

The consistency of the results from these experiments in diverse jurisdictions across the

country points towards generalizability to other contexts. However, the external validity is

necessarily limited since experimental population was diverse but not representative of all voters,

mid-term elections are distinct from other types of elections, and the 2010 election cycle had its

share of idiosyncrasies. As with all experiments the accuracy of and certainty about the results

will increase with replication across geography, election types, and other contexts.

29

The results of the experiments provide important insights about voting behavior. Voter

mobilization efforts appear to only get one bite at the apple, since the sequential mobilization

treatments generated no additional increase in turnout. Moreover, it appears that citizens make

their decision about whether to vote when initially mobilized and stick to it throughout the

election cycle. Encouragement to use different, later modes of voting does not prompt new

consideration of turning out at least not new consideration that leads to a decision to participate

among citizens who would otherwise not do so. In sum, the results of these experiments on

sequential mobilization support a Columbia School-type view of citizens that make up their

minds and those minds stay made up despite the stream of communication during the election.

Viewing the results of these experiments as a measurement of the effects of voting

reforms, we do not find support for either of the prominent perspectives in the debate over pre-

Election Day voting. The increase in turnout when voters are initially mobilized for VBM and

EIPV indicates that there is potential for these reforms to increase turnout when citizens are

informed about them, despite the pessimism from the observational research using aggregate

data. It seems likely that the observational research on voting reforms is correct that simply

passing these reforms does not increase turnout, but the problem may be reformers and scholars

unrealistic build it and they will come expectations about seeing effects from institutional

reform. The potential for the pre-Election Day voting reforms to increase turnout through lower

costs of voting cannot be realized until and unless citizens are informed about how to vote using

these methods. On the other hand, the failure of sequential mobilization treatments to deliver any

additional increase in turnout is likely a disappointment to supporters of pre-Election Day voting

reforms. If turnout does not increase in response to encouragement to utilize each type of voting,

it is very unlikely that the mere existence of multiple options for voting increases turnout.

30Allowing multiple choices for how to vote may have other benefits, but these experiments

indicate that offering multiple choices of how to vote does not lead more citizens to vote.

Although the logic for why civic and political organizations would pursue a sequential

mobilization strategy seemed reasonable prior to these experiments, the consistent results across

all four experiments indicate that sequential mobilization wastes scarce resources for voter

mobilization. Voter mobilization efforts will do more to reduce the participation deficit in the US

by broadening their targeting than pouring resources into sequential mobilization strategies that

attempt to squeeze more mobilization out of a narrower group. It may also be valuable to invest

in research about whether different types of citizens are more responsive to mobilization using

different voting methods.

In future research on voting when multiple methods are available, the research design in

these experiments could be improved upon in several ways: The most obvious improvement

would be a full factorial design to compare mobilization for all possible combinations of voting

modes including mobilization for each mode individually. Thanks to the interest and

cooperation of our partners organizations, our design made the best of our opportunity and

provides new and useful insights about voting behavior, institutional reforms, and mobilization

tactics. However, a full factorial design would facilitate answering additional questions about the

relative efficacy of mobilizing voters for different methods of voting. Another direction for

future replication is testing additional treatments for later methods of voting. Our treatments

utilized best practices from prior field experiments in order to maximize the impact of the EIPV

and Election Day voting mobilization treatments, but it remains possible that other tactics could

be more successful in generating marginal increases from sequential mobilization strategies.

One important future research question arising from these results is whether

31ineffectiveness of sequential mobilization applies to communication from one organization or

applies to communication from all civic and political organizations. The failure of sequential

mobilization by a particular organization is frustrating to that organization, but leaves open the

possibility that additional turnout might generated through mobilization efforts by other

organizations. However, if sequential mobilization for later modes of voting by all organizations

fails to produce additional increases in turnout then there is only very limited capacity in the

collective voter mobilization efforts of civic and political organizations to bring about major

reductions in the voting participation deficit in the US.

8. Conclusion

These four field experiments investigating the effects of sequential mobilization

contribute to closing the current deficit in understanding the complexity of voting and voter

mobilization when citizens can choose among multiple methods of voting. As pre-Election Day

voting continues to grow in use and spread to new jurisdictions in the US (and other

democracies), scholars must account for how the opportunities and challenges opened up by

these changes affect voters, elections, and civic and political organizations. Our experiments

clearly and consistently show that mobilization for the first method of voting increased turnout

but sequential mobilization did generate any additional increase in turnout. For civic and political

organization, the finding points to a need to reconsider using sequential mobilization strategies.

The findings expand our understanding of when and how voters make the decision about whether

to vote. Finally, the experiments indicate that voting reforms may offer more opportunities to

increase turnout than skeptics about pre-Election Day voting think but have much less impact on

turnout than supporters hope.

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36

Table 1: Randomization Balance Check - Experiment 1 (Maryland)

Individals

Unique Household

s

Mean Age Female

African America

n Hispanic

Voted in 2008

General

Voted in 2006

General

Voted in 2004

General Control 9,692 8,634 42 60% 13% 4% 92% 20% 51%

VBM Recruitment Treatment 19,645 17,399 42 60% 13% 4% 92% 20% 50%

VBM Recruitment & EIPV GOTV Call Treatments 23,747 21,071 42 60% 12% 4% 93% 19% 50%

VBM Recruitment & Election Day GOTV Call Treatments 19,613 17,352 42 59% 12% 4% 92% 20% 50%

VBM Recruitment, EIPV GOTV Call, & Election Day GOTV Call Treatments

23,873 21,110 42 60% 12% 4% 92% 19% 50%

Multinomial Logistic Regression

2= 21.81 (28 d.f.) p=0.790

37

Table 2: Change in Voting Behavior - Experiment 1 (Maryland) Intent to Treat Effects in Percentage Points

Total Turnout Voting By Mail Early In-Person

Voting Election Day

Voting (a) (b) (c) (d) (e) (f) (g) (h)

VBM Recruitment Treatment 1.8*** 1.9*** 4.3*** 4.3*** -1.4 -1.4 -1.1 -1.0

Robust Clustered SE 0.6 0.6 0.2 0.2 0.2 0.2 0.6 0.6 VBM Recruitment + EIPV GOTV Call Treatments 1.1** 1.2** 4.0*** 4.0*** -1.0

-1.0 -1.9 -1.9

Robust Clustered SE 0.6 0.6 0.2 0.2 0.2 0.2 0.6 0.6 VBM Recruitment + Election Day GOTV Call Treatments 1.0* 1.2** 4.1*** 4.1*** -1.3

-1.3 -1.8 -1.7

Robust Clustered SE 0.6 0.6 0.2 0.2 0.2 0.2 0.6 0.6 VBM Recruitment + EIPV GOTV Call + Election Day GOTV Call Treatments

1.6*** 1.7*** 4.0*** 4.0*** -1.2 -1.2 -1.2 -1.1

Robust Clustered SE 0.6 0.6 0.2 0.2 0.2 0.2 0.6 0.6 Participation in Control Group 42.4% 2.2% 4.3% 35.9% Covariates N Y N Y N Y N Y F-Test of Equivalence of Treatments 0.341 0.321 0.709 0.589 0.057 0.059 0.199 0.196

N (unique households) 85,566 one-tailed test: * p

38

Table 3: Randomization Balance Check - Experiment 3 (Idaho & Ohio)

VBM Recruitment Treatment

Individals Unique Households Age Female African

American Hispanic Voted in

2008 General

Voted in 2006

General

Voted in 2004

General Idaho Ohio

Control 7,722 7,151 43 66% 1% 1% 89% 22% 61% 31% 69% Treatment 70,199 64,856 43 64% 1% 1% 90% 23% 61% 32% 68%

Multinomial Logistic Regression 2= 3.41 (7 d.f.) p=0.845

Election Day GOTV Phone Treatment

Individals Unique Households Age Female African

American Hispanic Voted in

2008 General

Voted in 2006

General

Voted in 2004

General Idaho Ohio

Control 54,590 50,351 43 64% 1% 1% 90% 22% 61% 32% 68% Treatment 23,331 21,524 43 64% 1% 1% 90% 23% 61% 32% 68%

Multinomial Logistic Regression 2= 3.05 (8 d.f.) p=0.880

39

Table 4: Change in Voting Behavior - Experiment 3 (Idaho & Ohio) Intent to Treat Effects in Percentage Points

Total Turnout Voting By Mail Early In-Person

Voting Election Day

Voting (a) (b) (c) (d) (e) (f) (g) (h)

VBM Recruitment Treatment 2.2*** 2.1*** 3.9*** 3.9*** 0.0 0.0 -1.7 -1.8

Robust Clustered SE 0.6 0.6 0.4 0.4 0.1 0.1 0.6 0.6 VBM Recruitment & Election Day Phone Call Treatment 2.9

*** 2.7*** 4.3*** 4.3*** 0.0 0.0 -1.4 -1.6

Robust Clustered SE 0.7 0.7 0.4 0.4 0.1 0.1 0.6 0.6 Participation in Control Group 42.8% 8.5% 0.3% 34% Covariates N Y N Y N Y N Y F-Test of Equivalence of Treatments 0.118 0.105 0.156 0.115 0.196 0.195 0.526 0.566

N 72,007 one-tailed test: * p

40

Table 5: Randomization Balance Check - Experiment 2 (North Carolina - VBM, EIPV & Election Day)

Individals Age Female African American HispanicVoted in

2006 General

Voted in 2004

General Control 39,000 42 81% 27% 2% 6% 43%

VBM Recruitment Treatment 22,500 43 81% 27% 2% 6% 43%

VBM Recruitment, EIPV Phone Call, & Election Day Phone Call Treatment

22,500 42 81% 27% 2% 6% 43%

Multinomial Logistic Regression

2= 5.70 (12 d.f.) p=0.931

41

Table 6: Change in Voting Behavior - Experiment 2 (North Carolina) Intent to Treat Effects in Percentage Points

Total Turnout Voting By Mail Early In-Person

Voting Election Day

Voting (a) (b) (c) (d) (e) (f) (g) (h)

VBM Recruitment Treatment 1.8*** 1.8*** 3.5*** 3.5*** -0.4 -0.4 -1.3 -1.3

Robust SE 0.4 0.4 0.2 0.2 0.2 0.2 0.4 0.4 VBM Recruitment + EIPV Mailing + Election Day Phone Call Treatment

1.5*** 1.5*** 3.6*** 3.6*** -0.5 -0.5 -1.6 -1.7

Robust SE 0.4 0.4 0.2 0.2 0.2 0.2 0.4 0.4 Participation in Control Group 33.7% 1.2% 7.4% 25.0% Covariates N Y N Y N Y N Y F-Test of Equivalence of Treatments 0.496 0.575 0.538 0.429 0.782 0.812 0.362 0.346 N 84,000 one-tailed test: * p

42

Table 7: Randomization Balance Check - Experiment 4 (North Carolina - EIPV & Election Day)

Individals Unique Households Age Female African

American HispanicVoted in

2006 General

Voted in 2004

General

Control 11,063 10,527 45 84% 20% 2% 8% 50%

VBM Recruitment Treatment 18,382 17,500 45 84% 20% 2% 8% 49%

VBM Recruitment, EIPV Phone Call, & Election Day Phone Call Treatment

18,430 17,500 45 84% 20% 2% 8% 49%

Multinomial Logistic Regression

2= 6.40 (12 d.f.) p=0.895

43

Table 8: Change in Voting Behavior - Experiment 4 (North Carolina - EIPV & Election Day) Intent to Treat Effects in Percentage Points

Total Turnout Voting By Mail Early In-Person

Voting Election Day

Voting (a) (b) (c) (d) (e) (f) (g) (h)

EIPV Mail Treatment 0.7 0.8* -0.1 -0.1 1.5*** 1.5*** -0.6 -0.6

Robust Clustered SE 0.6 0.6 0.1 0.1 0.4 0.3 0.5 0.5 EIPV Mail & Election Day GOTV Call Treatment 0.6 0.7 0.0 0.0 1.2

*** 1.2*** -0.5 -0.5

Robust Clustered SE 0.6 0.6 0.1 0.1 0.3 0.3 0.5 0.5 Participation in Control Group 35.3% 0.9% 8.5% 25.9% Covariates N Y N Y N Y N Y F-Test of Equivalence of Treatments 0.888 0.832 0.282 0.234 0.329 0.318 0.780 0.825

N 47,875 one-tailed test: * p