Introduction

Deliberation on the offers and merits of politicians is a central element of the democratic exercise. Electoral campaigns are highlights of this exercise. Parties and candidates compete to convey their messages to an audience from which they expect to obtain a favorable decision and more concretely, the necessary number of votes to win the election. More than ever, political actors have intensified their communication with voters —within the legal framework that regulates it. This conversation between politicians and the public reaches voters through the media, either through the coverage of campaign events by the news media or through political advertising, in such a way that campaign effects are, ultimately, media effects.

In the 2018 presidential election, media attention to the candidates’ campaigns was intense and all of them spread their publicity in the time slots marked by the law. Likewise, all had a notable presence in social networks.

The academic literature regarding the media-driven relationship between politicians and voters has a long tradition in advanced democracies and, over time, has presented opposing views. Early studies supported the idea that the media had “minimal effects” on voters’ electoral preferences because electoral choice was shaped by individuals’ belonging to broad social groups with common characteristics and because media supply was limited to only a few outlets (^{Katz and Lazarsfeld, 1955}; ^{Klapper, 1960}). A second wave of studies supported the idea of significant media effects on preferences. The literature of this period attributed enormous influence to political marketing on voter preferences, from which it inferred a manipulated and even corrupted electoral competition, particularly because of the decisive influence of television on election results (^{Manin, 1997}; ^{Sartori, 1989}, among others).¹

The forms and means of access to information have dramatically changed during the last two decades. On the one hand, the media supply has become much broader and diverse, with the emergence of exclusive news channels, some with explicit political and ideological orientations. In many countries, state networks and channels compete with private channels. On the other hand, the emergence of the Internet has given way to new instruments of information consumption, such as social networks, where the public is informed directly, without editors who classify and order the news. Public access to information is increasingly individualized due to a massive and sometimes ideologically oriented supply as well as to new forms of person-to-person, unedited information exchange. All these changes force us to review our previous conclusions about the media effects on voting. The media in Mexico has undergone a similar process of change that is said to have played an important role in the 2018 presidential election.

Media consumption can have three effects on voter preferences; First, the information acquired during the campaign confirms the preferences the voter had at the beginning of the campaign, i.e. her candidate preferences do not change; second, the voter drops the candidate she preferred at the beginning of the campaign, i.e. the candidate loses the voter’s preference; and third, the voter changes her preferences in favor of another candidate, i.e. the latter gains the voter’s preferences. The central purpose of this study is to determine if any significant relationship can be identified between the voter’s information sources and how vote preferences moved during the campaign.

This article main draws from the CIDE-CSES 2018 National Election Study. This study consists of a national panel survey of the same individuals in four waves. The first wave was conducted between May 22 and June 3, the second between June 22 and 28, and the third —the first post-election wave— between July 12 and 18. The last wave was conducted in January 2019, with the new government in place. In this article I use only the first three waves. The survey strategy allowed us to interview the same 1 237 individuals in each of the first three waves. For the fourth wave, recollected six months later, 221 participants were lost —an attrition of 18 per cent. The methodology of these surveys is described in detail in Annex 1.

News coverage

As in any presidential election, campaigns were prominent in the news media. Table 1 shows the results of the news coverage analysis carried out by students of the UNAM’s Faculty of Political Science in 2018 on the INE’s behalf (^{INE, 2018b}). The news coverage of the candidates’ activities was mostly neutral. When the media goes evaluative, the marks usually lean “negative”; it is critical-oriented information. Table 1 shows that López Obrador was the candidate who received slightly more media coverage, especially during the pre-campaign, but also that he was the candidate with the highest number of negative notes, eleven per cent compared to an average of five per cent for the other two leading candidates. That is, contrary to expectations, the candidate with the most negative coverage was the one who increased his vote preferences the most during the campaign and ended up carrying the election.

For the primary source of voter information, the CIDE-CSES 2018 National Election Study includes a set of questions asking participants to indicate how often they heard campaign news on radio, television, print media, Facebook, Twitter and WhatsApp.² There are other networks available to the public, but several accounts indicate that these three are the most used by candidates and parties to spread political messages (^{Vázquez, 2018}).³

The data reveal marginal voter attention to news information, except for television broadcasting (see Figure 1). Only 30 per cent of our sample seek news information between four times a week and almost daily on any news source. As usual, the role of television as the most used source of information stands out: 51 per cent of interviewees consult news about the campaign on television, 26 per cent on Facebook, 24 per cent on radio, 20 per cent on WhatsApp, 16 per cent on print media and only 6 per cent on Twitter. If we remove the two most extreme channels —television and Twitter—, only an average of 24 per cent of people sought information about the campaign more than four days a week.

Source: National Electoral Study CIDE-CSES 2018 (^{Beltrán, Ley and Castro Cornejo, 2020}).

FIGURE 1 Information source of the campaign: Usage frequency per week 

Advertising

Political advertising in mass media is another central instrument for any political campaign. While the consumption of news through any source —however broad it may be— hits a limited and usually friendly public that is probably less susceptible to changes of opinion and preference, advertising reaches a much larger audience and is directly produced by the candidates themselves, so that it directly conveys the messages with which they want to win the vote. This is the reason why most campaign funding is used for political advertising.

The elections where candidates spend the most on political advertising are probably those in the United States, because of the characteristics of its electoral system and the cost of broadcasting, and yet there is no strong evidence indicating that advertising has a significant effect on voter preferences. The literature considers that the effect of political advertising on preferences is limited because candidates invest similar amounts to disseminate such advertising, surely under the assumption that if they do not do so they expose themselves to likely defeat (^{Iyengar and Simon, 2000: 151}; ^{Brox y Shaw, 2006}; ^{Zaller, 1996}). The result is that these conflicting messages nullify each other’s possible effect on voter preferences.

In Mexico, the rules of party access to mass media for the circulation of electoral propaganda changed radically in 2008. The reforms passed that year prohibited political parties and any other civil organization from directly buying slots on broadcasting networks to transmit any type of election-related message. To broadcast parties’ and candidates’ advertisements, as well as various INE announcements on the electoral process, the government granted free access to 12.5 per cent of the advertising slots that a previous law already granted, slots that the INE now distributes among the participating political parties for institutional broadcasting (^{DOF, 2018}).⁴ From then on, access to advertising time for electoral propaganda became markedly inequitable, since the law assigns 30 per cent of the time available to each of the registered parties and the remaining 70 per cent is distributed based on party votes collected in the previous election.

For the 2018 federal and local elections, the INE had access to nearly 30 million hours of airtime on all radio and television stations between December 14, 2017 and Election Day. This is equivalent to 48 minutes per day in media that were distributed in two and up to three minutes per hour of transmission on each radio station and television channel between 6:00 AM and 12:00 AM. Of these 48 minutes, the parties and candidates daily received 18 minutes on each radio station and television channel. In states with concurrent local elections, the INE allocated 15 minutes per day for local campaigns on each radio station and television channel with coverage in the state. The remaining time was available to the INE.⁵ Each party may freely decide how to distribute their messages in their corresponding time in both local and federal elections.

This change in parties’ and candidates’ access to airtime for the distribution of their political communication messages represented an enormous change compared to the time they used for the same purpose in the 2006 election. In that election period, 142 358 ads were broadcast; in 2018, parties and candidates broadcast just over 41 million ads (^{INE, 2018b}).

For the 2018 presidential election, the coalition Todos por México that nominated José Antonio Meade received 39 per cent of the total airtime available to broadcast its ads from the beginning of the pre-campaign until the election; the coalition Por México al Frente that nominated Ricardo Anaya received 37 per cent, and the coalition Juntos Haremos Historia that nominated Andrés Manuel López Obrador received 23 per cent.⁶ As noted, Ricardo Anaya and José Antonio Meade received similar amounts of airtime (37 and 39 per cent in total), while the winning candidate, López Obrador, received approximately 16 per cent less time and therefore a fewer amount of viewers.

Despite López Obrador’s disadvantage in accessing airtime for the dissemination of his messages due to electoral law, his campaign was very efficient since, as Figure 2 shows, his ads were remembered the most by the population.

FIGURE 2 Audience reached (GRPS, Nielsen México) and ad recollection (%) May 

In sum, the candidate who received the highest proportion of negative notes on the news coverage of his campaign and who had the least relative media airtime to transmit his ads, Andrés Manuel López Obrador, was the one who obtained the highest proportion of votes.

Changes in voter preferences

The electoral process officially began on December 14, 2017 with the start of what the law defines as the pre-campaign period, where parties and coalitions had to select their candidates, and independent candidates had to meet the requirements for registration. The period ended on February 11, 2018 (^{INE, 2017}). In November 2017, several polls showed that electoral preferences were largely distributed among four candidates: Andrés Manuel López Obrador with 35 per cent of preferences, Ricardo Anaya with 20 per cent, Miguel Osorio Chong with 30 per cent and Margarita Zavala with 12 percent. As shown, the preferences for the two potential candidates from the PAN added up to 32 per cent, a similar number to that of López Obrador, who was leading the polls. In other words, during the 2018 electoral process, vote preferences for López Obrador grew by nearly 18 percentage points, while preferences for Ricardo Anaya fell by 11 points and those for José Antonio Meade by seven. The following analyses begin in May because the first wave of the panel survey —which is its empirical basis— began on that date. Table 2 shows the changes in electoral preferences between May and the July post-election survey.

These changes in preferences may seem small. However, in reality almost 60 per cent of the panel participants changed their preferences between the first and the third wave, a very significant proportion of people, while the remaining 40 per cent maintained their preferences during the campaign.

To analyze what happened to voters’ preferences during the campaign between the first wave in May and that of July, I estimated three variables that identify whether the preferences for the candidate did not change, whether the candidate gained or whether he lost the voter’s preference. In Table 4, I present the percentage of panel participants who fall into each category for each candidate. It is important to note that this set only includes panelists who expressed preferences in May and July. One should also note that López Obrador was by far the candidate who retained or gained the most preferences compared to the other two: 46 per cent versus 22 per cent for Anaya and 26 per cent for Meade.

Analysis

Media and advertising consumption and changes in preferences during the campaign

In the previous section, we analyzed the relationship of media and advertising with voter preferences in a cross-sectional manner. The National Electoral Study is a panel survey that allows us to know the changes in candidate preference for each participant. Based on the preferences expressed in the first and third waves of the panel, I constructed a variable that shows how voter preferences evolved. The variable has a value of 1 if the candidate lost preferences of voters between May and July, 2 if he won them and 3 if the preferences he obtained in May did not change during the campaign. To estimate the effect of media consumption intensity and advertising recollection over voter’s preference stability during the campaign, I ran multinomial logistic models where the dependent variable is for each candidate whether he kept support, lost voters or won them between May and July, and the independent variables are media consumption intensity —measured by the times that the voter found out about the campaign through the media source in question per week— and the recollection of the candidates’ advertising. That is, the estimates show under what conditions the candidate lost or gained votes compared to those citizens whose vote did not change between May and July. Table 7 shows the results of the corresponding models.

The results are remarkably consistent regarding traditional media: radio, television and print. Models fail to report a statistically significant relationship between voter media consumption intensity and changes in voter preferences. In this sense, these results are also consistent with the broad literature that has found minimal or no effects between information sources and electoral preferences. The same could be said about social networks, if it were not for the visible relationship between their usage as a source of information and the change in preferences for Ricardo Anaya. However, the result is somewhat ambiguous, as it seems that the use of Twitter as a source of campaign information was associated with both favorable and adverse preferences for Anaya. These results are probably consistent with the nature of this network. As is well known, Twitter is a space where the greatest confrontation between opposing views occurs, some of them with the use of “professional” or even automated participants, the so-called bots.

This is a relevant finding that also brings into question the belief even expressed by López Obrador on several occasions about the positive role of social networks in his campaign. The results of the models reveal that there is no statistically significant relationship between the use of social networks as a source of information and the changes in preferences for López Obrador during the campaign.

To identify the possible effects of advertising on the change or stability of preferences, I ran multinomial logistic models where the dependent variable is the change or stability of preferences as described above and the independent variables are dichotomous variables that have the value of one if the interviewee recalled the candidate’s advertising and zero if he or she did not. The results can be seen in Table 8.

Advertising recollection does not show a statistically documentable relationship with the change or permanence of the voter’s preferences in the campaign either.

Conclusions

This article analyzed the relationship between media consumption and political ads recollection and vote during the 2018 presidential election in Mexico. Its main finding reveals that neither media consumption nor political advertising seemed to have a significant effect on the changes in preferences for any of the three major candidates. In this sense, this essay rules out the idea that the use of social networks was a decisive factor in the definition of voters’ electoral preferences in the 2018 presidential election. The same holds for the voters’ recollection of the candidates’ political advertising. These findings go well with the academic literature claiming that the media has minimal or no effect on voter preferences —not only traditional media, but the so-called social networks as well.