Campaigns and advocacy groups spend millions of dollars on these direct mail efforts each election cycle, believing that, with the right messages, they will win more recipients than they will lose. But new research shows that these campaigns can backfire, gaining the support of the target audience but losing the support of all other voters.
“The problem is that no one really understands how a given flyer or advertisement can motivate people to talk to others and spread information on social networks,” he says. Georgy Egorovprofessor of managerial economics and decision science at Kellogg.
Seeking to explore how messages ripple across social networks and better understand the full scope of a campaign’s impact, Egorov collaborated with Sergey Guriev of London Business School, Maxim Mironov of IE Business School, and Ekaterina Zhuravskaya of the Paris School of Economics.
Economists have developed a new way to simultaneously measure the direct and indirect effects of a political campaign and applied it to study Argentina’s 2023 presidential election, which was won by outsider, replacement and right-wing candidate Javier Millay. They focused their efforts on a pamphlet campaign that provided expert information on the potential negative consequences of some of Millay’s extreme proposals.
Overall, people who received one of the leaflets were less likely to vote for Milei. So at least on the surface, the campaign went as expected.
But the campaign also had an indirect effect on voters in the same locations, which completely shattered expectations. Among those who did not receive a leaflet, support for Milei not only increased; it went up so much that it overshadowed the immediate effect.
In other words, this particular campaign failed, ultimately harming the cause it was supposed to help.
“That the indirect effect was greater than the direct effect—and also in the opposite direction—is not something we expected,” says Egorov. “It really challenges what we know about the spread of ideology on social networks.”
Ideal setting
Unlike many other countries, Argentina’s election results are reported at the subdistrict level, with voters assigned to a specific “middle” based on the first letter of their last name. Political parties in Argentina are also required by law to publish a list of their members’ names and addresses.
This arrangement allowed the NGO the group was working with to know not only which residents who voted in a particular district would receive leaflets and who would not, but also how the groups who received the leaflets and those who did not ended up voting.
“This allowed us to measure how people who lived in the same area voted and differed only by whether the campaign directly targeted them or not,” says Egorov. “In addition to looking at individual votes, this is an ideal situation for identifying the direct and indirect effects of a campaign.”
Together with the NGO, Egorov and his team designed two different pamphlets that tested Javier Milei’s policy proposals.
The first draft explained that Milei’s plan to abolish the Central Bank and dollarize the economy would cause significant devaluation and inflation. The second described how Miley’s plan to replace public funding for secondary schools with vouchers would hurt the nation’s education system.
A highly unusual result
Before the start of the general election, the group mailed 5,000 of each type of leaflet to a random selection of individual residents who voted in specific sub-districts of Salta province (outside the capital), where Milei had received the highest percentage of votes in the recently concluded primaries.
Overall, the first inflation brochure had no effect on voting results, likely because the issue was very familiar to voters and was widely discussed in the media.
In contrast, the education flyer reduced voter support for Milei by about 20 votes per 100 flyers mailed — but only among residents who received a flyer. Among residents of the same district who did not receive a leaflet, voter support for Miley rose with about 30 votes per 100 postal letters.
The net result was an increase of 10 votes for Milei per 100 leaflets mailed.
“When we got the results, we thought, ‘something very unusual is happening here,'” says Egorov. “We wondered to what extent this was a statistical fluke.”
When Milei emerged from the first round of the general election as one of two finalists, the researchers realized they had an opportunity to confirm their initial findings in a follow-up test. They sent 5,000 of their “education” leaflets to a random selection of residents — who lived in the same province but did not receive a leaflet in the first phase — ahead of the run-off election between Milei and the front-runner, Sergio Massa.
As in the first phase, the campaign reduced voter support among residents who received a flyer, though not as much this time—perhaps because more voters had made up their minds about Milei by the second round. In contrast, the indirect effect remained positive and just as strong: even if leaflets were less likely to change people’s minds, their desire to talk about the election to friends and neighbors seemed to remain just as high.
The team also looked at the effects of the first phase on the second round to see if the effects were persistent or short-lived. “Surprisingly, we didn’t see decay in the second round,” says Egorov. “If anything, the indirect effect became greater. It’s almost as if people had more time to talk to their friends and neighbors about the information they had learned.”
He is motivated to speak
Why did the “education” campaign fail so spectacularly?
One possible explanation, according to the researchers, is that voters who received a pamphlet and disagreed with it were much more vocal about their opinion and more likely to persuade their neighbors to vote for Milei.
“Clearly, some voters found the arguments persuasive. But some apparently felt it was an unfair attack on a candidate they really liked — so it turns out those voters were more motivated to talk to their friends,” Egorov says. “And they happened to be far more effective than any kind of political campaign could be.”
The team substantiated this theory in a survey of voters long after the presidential election was over. The survey asked people to imagine either believing or not believing information in a pamphlet about a hypothetical presidential candidate, and then to indicate how likely they would be to tell their friends and neighbors about it. Survey respondents who were told not to believe the information were not only prepared to tell more people about it, but also more motivated to persuade others to vote for the candidate criticizing the leaflet.
“Obviously, it’s easier to upset and anger people on the other side than to energize your supporters,” Egorov says.
Putting assumptions aside
The study’s findings offer valuable lessons for campaigning and outreach efforts, even beyond the political sphere. First, “you can’t always transfer things that work in the lab to the field,” says Egorov.
The researchers’ “training” pamphlet, for example, would have followed the typical focus group or lab-based test that campaigns typically rely on to predict how people will respond to their messages. But as the study’s findings revealed, such test results would likely be highly misleading when applied to the real world.
Equally important to campaigning and outreach efforts is to consider how their messages may affect people beyond their target audience. For example, political campaigns too often fixate on swing voters and overlook large segments of the population. For managers and marketers, the lesson is similar: it is not enough to understand how the target audience reacts. you also need to predict who is most likely to talk about your message and how.
Finally, the study’s findings underscore the importance of setting aside assumptions when trying to understand how people might respond to new information and interact with others.
“When we accepted that our—and our profession’s—assumptions about how things spread on social networks were too simplistic,” says Egorov, “then we learned something new.”
