Vote-by-mail had surprisingly little effect on turnout in 2020, new study shows

Republicans and Democrats don’t see eye to eye on much surrounding the 2020 election, but they largely agree on one thing: Mail-in ballots surged because of the pandemic, massively increasing voter turnout and delivering the White House to Joe Biden.

There’s just one problem. Conventional wisdom is probably wrong, says Andrew Hall, a senior fellow at the Stanford Institute for Economic Policy Research (SIEPR) and co-author of a new working paper analyzing last fall’s voting patterns.

The record number of absentee votes did not drive the extraordinary increase in overall turnout, according to Hall and his team of mostly Stanford researchers at the Democracy & Polarization Lab. Most people who voted by mail most likely would have voted in person had voting by mail not been an option. In fact, turnout rose by a similar amount in states that didn’t even allow no-excuse absentee voting — the most common form of mail-in balloting and the one the researchers study — in 2020.

Their analysis also suggests that mail-in voting did not dramatically help Democrats, electorally. While no-excuse absentee voting led many Democrats to vote by mail, many Republicans voted in person.

“It’s true that turnout was extraordinarily high in 2020 and that more people voted by mail than ever before,” says Hall, a political science professor in Stanford’s School of Humanities and Sciences. “But it’s a fallacy to say that absentee voting therefore must have driven the increase in voter participation and that Democrats necessarily benefited more than Republicans as a result.” He says the results suggest that many Democrats who voted by mail would have voted in person had voting by mail not been an option.

Hall and his co-authors note that the false narrative around 2020 voting has both parties engaging in “rhetorical combat” around the future of the election process generally — and the role of absentee balloting specifically. According to a recent Wall Street Journal article about their study, Republicans in 30 state legislatures are moving to restrict mail-in voting this year.

Hall stresses that voting by mail should not be evaluated on the basis of its effect on turnout or whether it advantages one party or the other.

“A principled evaluation of voting by mail would focus on its strengths and weaknesses as a way to vote,” he says. “The fact that so many people chose to vote by mail indicates its likely value as a policy, especially considering that the claims about vote-by-mail and fraud have proven to be so hollow.”

Even if no-excuse absentee voting has surprisingly small effects on turnout, rolling it back could still be a bad idea. “Restricting voter access to popular, alternate modes of voting without good reason is anti-democratic, regardless of its actual effects on turnout,” Hall says. “This is particularly important in southern states with a legacy of intentional efforts to suppress the turnout of Black Americans.”

Nevertheless, the study findings are important for understanding why people vote and how policies can encourage turnout. The conventional wisdom around the 2020 outcome is based on a longstanding misconception about the role of convenience in elections, the researchers say. Politicians and reformers often focus on making voting more convenient, but it’s not the most important factor in driving participation, they argue. 

“Absentee voting doesn’t significantly affect whether people vote or not,” Hall says. “It mostly changes how they vote. Voter interest is far more important in determining turnout.”

The study’s other contributors were Jesse Yoder, Cassandra Handan-Nader and Tobias Nowacki, Stanford PhD candidates in political science; Andrew Myers, a predoctoral research fellow at SIEPR; Jennifer Wu and Chenoa Yorgason, Stanford PhD students in political science; and, Daniel Thompson, an assistant professor of political science at UCLA.

Insights from Texas

Before 2020, research into U.S. elections had already cast doubt on the impact of absentee voting on participation. Studies found, for example, that it at best moderately increases turnout, including among marginal voters. COVID-19, however, brought new urgency to the question given the perceived risks of in-person voting.

“We thought it was particularly important to understand how voting by mail affected turnout in 2020, given the way that the pandemic totally changed the world and the election, and given former President Trump’s unprecedented assault on the democratic system,” Hall says.

The first part of their study looks at nationwide data on 2020 turnout and voting policies for all 50 states. Surprisingly, they didn’t find that turnout rose much more in states that implemented no-excuse absentee voting than in states that did not. States newly implementing no-excuse absentee voting saw a 5.6 percentage point increase in the rate of turnout over 2016, while the turnout rate in states without no-excuse absentee voting rose 4.8 percentage points. 

“That difference is a lot smaller than conventional wisdom might suggest, and it could even be statistical noise,” Hall says.

While the nationwide analysis is suggestive, separating correlation from causation is hard without an experiment that varies the availability of voting by mail while holding all else equal. To get at an experiment like this, the researchers delved into election results in Texas, where only residents 65 years and older can vote by mail without an excuse. If the conventional wisdom was right — that the surge in turnout in 2020 resulted from mail-in voting and that Democrats benefited — the researchers would see a noticeable jump in turnout among 65 year-olds.

They didn’t see it in their dataset. Turnout between 64 year-olds, who by and large have to vote in person, and 65 year-olds was almost identical, despite the fact that 18% of ballots cast by the older group were absentee, while only 3% of the younger group’s ballots were absentee. As further evidence of vote-by-mail’s limited effects on voting, the scholars report that turnout rose most sharply among voters aged 20-30, even though nearly all of these younger voters had to vote in person.

Convenient, but not obviously partisan

The researchers also shed light on two other key issues. The first is whether Democrats won the presidency and Congressional control based on mail-in voting. Other research from the 2020 election has found that Democrats mostly stayed away from polling stations while Republicans largely voted in person.

Hall’s team finds that, in Texas, 30 percent of 65-year-old Democrats voted absentee — up from 10 percent in 2016. Republicans, meanwhile, cast 10 percent of their ballots through the mail, or the same amount as in the prior general election. But this gap in absentee voting was almost entirely canceled out by shifts from other modes of voting: 65-year-old Democrats who voted in the election were much less likely to vote early in person.

As a consequence, the authors do not find evidence for a major Democratic turnout advantage among 65-year-olds: They estimate that the proportion of voters who are Democrats among 65-year-olds is 0.2 percentage points higher than among 64-year-olds, despite the major differences in rates of voting absentee. 

The researchers also offer evidence, based on their Texas dataset, that the convenience of voting absentee does not motivate marginal voters to cast ballots. This is important for assessing whether the results in Texas might speak to other contexts where voting by mail was available for people below the age of 65, who will on average be less habitual voters. “We are also replicating our results in Indiana,” Hall added, “where the same age cutoff policy was in place. We are finding a similar non-effect on turnout there.”

Taken together, Hall says, the insights suggest that voters like the convenience of voting by mail, but that opportunity alone isn’t the reason they participate in elections. If anything, it benefits voters who are likely to cast ballots regardless of how they do it.

This said, convenience could matter in midterms — where voter interest is traditionally low — or in tight races where even a small bump in votes cast could tip the outcome in either party’s favor. 

Hall stressed that while the evidence tilts against dramatic partisan effects of voting by mail, it does not mean that no-excuse absentee voting could never change an election result. 

“In really close elections, like Georgia where Biden won by a quarter of a percentage point, we can’t say whether no-excuse absentee voting could have made the difference or not,” Hall says. “Realistically, no statistical procedure is going to be able to rule out tiny effects that could tip close races like those.” 

As a result, he says, Democrats and Republicans might have reason to fight over election rules in close races. “But the rhetoric suggesting it is the major explanation for everything happening in elections nationwide is misleading,” he says. “Vote-by-mail’s actual impact turns out to be quite muted.”

Krysten Crawford is a freelance writer.