Three weeks ago, the 2018 Brazilian election seemed like anyone’s ballgame. Jair Bolsonaro, the far-right candidate of the Partido Social Liberal (PSL), was in first place, but it was anyone’s guess how being stabbed at a campaign event on September 6 would affect his numbers. Fernando Haddad of the PT had only been an official presidential candidate for a few days thanks to ex-President Lula’s insistence on running a campaign from his jail cell.
Since then, things have gotten both clearer and murkier. Fernando Haddad and Jair Bolsonaro currently hold double-digit leads over center-left Ciro Gomes of the Partido Democrático Trabalhista (Democratic Labor Party) and center-right Geraldo Alckmin of the Partido da Social Democracia Brasileira (Brazilian Social Democracy Party), meaning that they would both go to the second round on October 28. There, however, they are technically tied according to most polls, and anything could happen; second-round predictions are hypothetical and volatile, and both candidates have rejection rates that are comfortably larger than their support rates.
On the one hand, Haddad could win by default, as the anti-Bolsonaro vote could crystallize into a pro-Haddad vote. On the other hand, Bolsonaro could win by default, as the anti-PT vote could crystallize into a pro-Bolsonaro vote.
Yet there are a few reasons why one should take the poll results currently in the news with a grain of salt. In fact, we could have a surprise in the first round on Sunday the 7th, never mind the second.
Polls have limited geographical reach
Polls in Brazil are limited in terms of their sampling. Infrastructure is not up to scratch in every part of Brazil, and polling institutes cut some corners sometimes, often opting not to use face-to-face polling or not using cell phones, so it ends up that not every part of Brazil actually makes its way into surveys.
To compensate, most major polling firms use quotas for certain demographic characteristics, not truly random samples. The specific formulas they use are generally not publicly available, but this is well-known among the scholarly and polling community. This has some knock-on effects, as I show below.
My own polling database–compiled with Mathieu Turgeon of the University of Brasília in a working paper that is currently under review–the average absolute polling error for presidential elections one day before the election has been 2.96 percentage points since 2002. In 2014, this rose to 4.86 percentage points. Compared to the U.S.’s average of 1.9%, the U.K.’s of 2.0%, Portugal’s of 2.4%, and France’s of 2.0%, this does not flatter Brazil’s polling.
The Supreme Electoral Court wiping out voters registrations
The Supreme Electoral Court (TSE) decided, this year, to require compulsory biometric registry for all voters. This required voters to go to the Electoral Court in their region and register their fingerprints. Unfortunately, as sometimes happens with major bureaucratic changes, the communication of this change was less than ideal, and 3.3 million voters (2.4% of the electorate) never did make this trip.
This left the TSE with a pickle: undermine the effort and let those who didn’t register vote anyway? Or, despite the fact that voting is compulsory, follow through and ban those who did not register from voting.
Unfortunately, the communication of this decision has also been less than ideal, as voters who have had their registration canceled have not been individually notified. In fact, they will only know that they can’t vote after they show up at the polls to try to vote. After all, if one didn’t find out about the initial decision to require fingerprints, it’s also likely that that person won’t know about the subsequent decision unless notified individually. To make matters worse, a rumor on Whatsapp has already circulated claiming that you can vote even without having done the registration if you show up with photo identification.
This could be a big deal. On a normative level, this registry cancellation is not randomly distributed among the population–it disproportionately will affect the poor and the uneducated, or in other words, those who most need political representation. On an empirical level, this could also make a difference; those with their registry canceled would likely not know, and would include themselves as voters to electoral polls (since everyone, in theory, is, unless they plan to justify not voting to the electoral board). If any candidate draws primarily on voters who are more likely to have not registered, this could cause them to underperform in relation to the polls. If this will hurt anyone, it will probably be Haddad because of his strength with poorer citizens.
The shy Bolsonaro vote
When Trump won, outperforming poll predictions, some political scientists and commentators proposed that many Trump supporters could have been reluctant to share their preference for him to pollsters. The evidence is mixed, but social desirability bias has been shown to weigh on polling results for a variety of subjects, including sex, drug use, and vote buying. It is not outside the realm of possibility that it could have applied to a candidate who was shunned in certain circles for controversial comments about blacks, Latinos, women (etc.). As the theory goes, certain types of voter might be happy to share his support of Trump with interviewers, but others are not, and might refuse to acknowledge that to pollsters while still voting for him.
This dynamic could possibly apply to a candidate such as Bolsonaro, whose fondness for crossing lines would even embarrass Trump. This barrier might have broken down as he has gained more attention, but one can never count out the possibility that people in certain environments might not want to openly show support for someone who says all sorts of repugnant things.
The evidence is not quite clear yet, though, so this is one we’ll have to wait and see about.
In Brazil, the exchange of money for votes on the eve of the election is still a common practice. Candidates with more money than scruples (or who would object to that characterization, but are afraid of their competitors of that profile) will commonly go to the streets the night before the election or the day of the election to try to win over undecided voters.
This practice–commonly called the boca de urna (literally, the mouth of the voting machine)–generally entails illicit campaigning. Either the campaign will send associates door to door the night before the election, or it will send its associates into the street the day of the election to intercept voters heading to the polls. These associates (who are generally several degrees away from a candidate herself so as to avoid implicating her directly) find undecided voters in the street or pass by the houses of people they already know. They then hand over a small campaign advertisement with the candidate’s name and number, and those of the candidates she supports, along with a certain amount of money (last election, between R$50-R$100). This practice can also happen without money changing hands, but it is not as effective.
For obvious reasons, it is extremely difficult to measure how common the boca de urna is and how much of an effect it has, but I gave it a shot (as mentioned above). It is more common for proportional elections (federal and state deputy), but it can also have knock-on effects for majoritarian elections (like president) when people don’t have their own preferences for candidates. We find that, when at least 15% of the electorate is undecided the day before a given majoritarian election, polling error increases in conjunction with financial differences between campaigns (this year, the most recent polls are showing between 13% and 17% undecided). The true effect is likely much higher because campaigns almost always leave many resources undeclared to the TSE.
This type of practice requires, above all else, two things: money and political alliances. Big majoritarian campaigns can’t organize this alone because it requires local knowledge–where to go to buy votes without being caught, who to go to, etc. It also requires financial resources–enough to buy the proportional campaigns and local politicians (e.g., mayors and city councilmen) who do the buying, and for them to in turn buy brokers, and for those brokers, in turn to buy votes.
It is likely no coincidence, therefore, that deep-pocketed campaigns like the PSDB’s tend to grow towards the end of the campaign, whereas candidates such as Marina Silva, who have less money and are loathe to ally with other candidates, tend to fall away; Marina won, on average, 2.2% less than predicted in 2014 while the PSDB’s Aécio Neves won an average of 5.4% more. This dynamic looked most likely to help a candidate like the PSDB’s Geraldo Alckmin, and hurt Marina and Bolsonaro, but Bolsonaro’s recent endorsement from the wealthy rural caucus means that this might have shifted in a direction that will not hurt Bolsonaro, and even might help him.
A surprise in the works?
This does not mean that Haddad and Bolsonaro will not make the second round, but Brazil always throws up some surprises in elections. This year, they could be more pronounced. Don’t be surprised if one or more candidates receives a vote total significantly off the latest polling figures.
If we have 5% errors again, that could mean that Ciro Gomes takes Haddad’s place, or that Haddad takes first place. One candidate could limp into the second round demoralized, finding it difficult to negotiate alliances. Or, given the number of hidden factors that could help Bolsonaro, it might also mean that the errors go in the other direction.
In that case, a second round might not even be necessary.