Media Campaigns and Euroscepticism

When theorists worry about the persuasive power of the media, they usually refer to sustained one-sided campaigns by a medium or multiple media outlets that are meant to explicitly influence public opinion in a specific direction (Horkheimer, Adorno, and Noeri Reference Horkheimer, Adorno and Noeri1972; Lippmann Reference Lippmann1921). Media outlets can act as “political actors” (Page Reference Page1985) and “issue entrepreneurs” (de Vries and Hobolt Reference de Vries and Hobolt2020; Hobolt and de Vries Reference Hobolt and de Vries2016), raising the salience of a specific political issue while at the same time providing a strong frame that citizens rely on to interpret the issue (Leeper and Slothuus Reference Leeper, Slothuus, Grofman, Suhay and Trechsel2020). As Page (Reference Page1985, 20) writes, we should understand certain media outlets as political actors who “try and change the beliefs and policy preferences of mass and/or elite audiences, which would presumably affect subsequent policy decisions.” This assumes that these media outlets or their owners act purposefully to influence public opinion and that citizens can be receptive to such influences.

The latest experimental (Arceneaux and Johnson Reference Arceneaux and Johnson2013; Arceneaux and Kolodny Reference Arceneaux and Kolodny2009; Broockman and Kalla Reference Broockman and Kalla2016) and quasi-experimental (Jäger 2020) literature on issue-based campaigns and framing effects suggests that persuasion effects can materialize under favorable scope conditions: when audiences are not self-selecting into receiving political messages, but receiving them as a by-product (Arceneaux and Johnson Reference Arceneaux and Johnson2013), when campaigns target emerging rather than highly salient or polarized issues (Arceneaux and Kolodny Reference Arceneaux and Kolodny2009), and when messaging is one-sided or loop-sided (Jäger 2020). As Zaller (Reference Zaller1992) has shown, messages should be more effective at influencing opinions if the audience is not highly politically interested or engaged. This leads to the apparent paradox that those most likely to accept persuasive messages are least likely to receive them (Zaller Reference Zaller1992). Building on these insights, Arceneaux and Johnson (Reference Arceneaux and Johnson2013) have argued that audiences that consume a medium for entertainment purposes should be more likely to change their opinion if they receive political news via that medium than audiences that consume the medium because they intend to consume political news.

Arceneaux and Kolodny (Reference Arceneaux and Kolodny2009) show that voters changed their minds when exposed to messages on birth control but not on the highly salient issue of abortion. On highly salient issues, citizens will already hold crystallized attitudes that are difficult to move. This is consistent with findings by Gerber, Karlan, and Bergan (Reference Gerber, Karlan and Bergan2009) who report null effects of subscribing to either the Washington Post or the Washington Times on opinions toward the Iraq War in 2005. Clearly, Iraq was a highly salient issue in the United States in 2005. Moreover, the framing literature suggests that one-sided messaging is particularly effective (Chong and Druckman Reference Chong and Druckman2007). We should thus expect media effects to materialize in political environments characterized by one-sided messaging on emerging issues. We therefore deduct that if exposure to strong frames happens in the absence of effective counter frames, the media should be able to shape strong attitudes in relation to an issue. As Chong and Druckman (Reference Chong and Druckman2013, 13) write, once “strong attitudes are accessible, counter-frames are rejected and may even serve to reinforce the original attitude.” Strong attitudes are then difficult to change going forward and will be less likely to decay.

One of the key remaining challenges in the study of media effects is thus to identify the consequences of sustained exposure to media content, so-called media campaigns, on specific issues of policy importance. A prime example of such a media campaign is the one-sided negative coverage that the European Union (EU) was subject to over three decades in the British tabloid press (Hobolt and Tilley Reference Hobolt and Tilley2014; Jackson, Thorsen, and Wring Reference Jackson, Thorsen and Wring2016). While the EU issue in the 2010s had become highly salient and during the EU referendum campaign reporting was balanced, English voters had been exposed to Eurosceptic content for decades (Jackson, Thorsen, and Wring Reference Jackson, Thorsen and Wring2016; Levy, Aslan, and Bironzo Reference Levy, Aslan and Bironzo2016). One remarkable aspect of this exposure is that a lot of it happened inadvertently while consuming tabloid media for their celebrity or sports coverage (Rooney Reference Rooney, Sparks and Tulloch2000).

Eurosceptic media outlets and the reporters associated with them had consistently portrayed European integration as a threat to sovereignty and the EU as an inflexible and irrational bureaucracy imposing layers of red tape on member states (Jackson, Thorsen, and Wring Reference Jackson, Thorsen and Wring2016). While many researchers (de Vreese Reference de Vreese2007; Hooghe and Marks Reference Hooghe and Marks2007) and columnists (Bennhold Reference Bennhold2017; Martinson Reference Martinson2016) have wondered whether the tabloid press have contributed to the rise of Euroscepticism—the (qualified) rejection of European integration (de Vries Reference de Vries2018; Vasilopoulou Reference Vasilopoulou2013), across Britain and other European countries—testing this claim is difficult. Researchers have relied mostly on cross-sectional surveys (Carey and Burton Reference Carey and Burton2004) or panel studies to control for time-invariant confounders (de Vreese and Boomgaarden Reference de Vreese and Boomgaarden2006). Survey-experimental studies suggest that there can be immediate effects of Eurosceptic media frames on public attitudes, for instance toward EU enlargement (de Vreese, Boomgaarden, and Semetko Reference de Vreese, Boomgaarden and Semetko2011). Thus, while there is evidence that media slant is correlated with public attitudes and experiments show that Eurosceptic frames and primes can have immediate effects in the direction of the information, it remains unclear whether sustained Eurosceptic media campaigns are able to consequentially influence public opinion in the long run.

The Case: Hillsborough and the Merseyside “Sun” Boycott

To study such sustained media effects in a real-world setting, we need to observe substantial and relatively sudden change in media landscapes. Yet, media landscapes are normally relatively stable and change slowly; on rare occasions media outlets enter or exit existing media markets, offering opportunities to study the effects of newspapers or TV channels on political outcomes (DellaVigna and Kaplan Reference DellaVigna and Kaplan2007; Gentzkow, Shapiro, and Sinkinson Reference Gentzkow, Shapiro and Sinkinson2011). However, the decision to enter or exit a media market can be endogenous to political or economic considerations such as consumer demand or the lack thereof (Gentzkow, Shapiro, and Sinkinson Reference Gentzkow, Shapiro and Sinkinson2011). Normally, media boycotts also follow a political logic. We overcome this endogeneity concern by relying on the case of the long-lasting “Merseyside Sun boycott,” which was caused by an exogeneous event, the Hillsborough sporting disaster involving Liverpool F.C., and the ensuing slanderous media coverage in The Sun tabloid, which led to a geographically restricted boycott of the paper.

On April 15, 1989, Liverpool F.C. played Nottingham Forest in the semifinals of the British Football Association (FA) Cup in the Hillsborough stadium. Due to overcrowding and an ensuing mass panic, 97 Liverpool supporters lost their lives, hundreds were injured, and thousands traumatized (Scration Reference Scration2004; Wright Reference Wright1993; Wright, Gaskell, and O’Muircheartaigh Reference Wright, Gaskell and O’Muircheartaigh1998).Footnote ² As pictured in Figure 1, The Sun’s sensationalist coverage of the disaster was particularly one-sided and falsely claimed that “the truth” about the disaster was that Liverpool supporters were responsible for the chaotic escalation, and ultimately, for their own death.

Figure 1.

The Sun’s Hillsborough and EU coverage

Sources: British Newspaper Archive (British Library) and Woodhouse, Cole, and Pettit (Reference Woodhouse, Cole and Pettitt2016).

Based partly on false information by a South Yorkshire police inspector, The Sun claimed that Liverpool supporters had stolen from the dead as the disaster unfolded. According to The Sun’s source, one of the victims had “numerous wallets” on him, and was likely “one of the Liverpool pickpockets.” Despite what would turn into a commercial disaster for the paper, The Sun remained unapologetic. This stubbornness led to a boycott of The Sun in the Merseyside area. Soccer is very important to Liverpudlians’ identities and to the city of Liverpool (Alrababah et al. Reference Bartels2021). The Sun boycott was initiated by football supporters and their family and friends stopping purchasing the tabloid in protest of The Sun’s coverage, and soon the boycott was coordinated by the Hillsborough justice campaign (BBC 2012). The boycott has not only been supported by fans of Liverpool F.C., the most popular soccer club in Merseyside, but even supporters of Premier League rival Everton F.C. showed their solidarity with Liverpool supporters and the Hillsborough 97 and vouched never to buy The Sun again. Until today, this boycott is ongoing. In 2017 after speaking to several victims of the Hillsborough disaster, the club owners and the manager Jürgen Klopp decided to ban all “Sun” journalists from entering their stadium at Anfield Road and their training grounds (Conn Reference Conn2017).

The Sun’s version of the Hillsborough disaster was comprehensively contradicted by multiple reports released by the official Hillsborough Independent Panel, which pointed to the catastrophic mishandling of the situation by the police (House of Commons 2012). The Guardian estimates that in the wake of the Hillsborough disaster, The Sun’s circulation fell from 55,000 copies to just around 12,000 copies in Merseyside, although these figures cannot be independently verified (Brook Reference Brook2005).

Thus, to achieve valid and reliable information about the extent of the boycott in Merseyside, we conducted a telephone survey. More precisely, in January and February 2021 we surveyed the entire population of newsagents and cornershops located in Merseyside and two directly adjacent counties, Lancashire and Cheshire, listed on Yelp where a functioning telephone number could be located either on Yelp or Google Maps.Footnote ³ Newsagents were interviewed about newspaper sales, with no reference to Hillsborough or The Sun boycott. The results clearly confirm that The Sun boycott in Merseyside is widespread. Overall, 62% of newsagents’ in Merseyside reported not selling The Sun. This figure increases to 86% in the city of Liverpool. The survey also shows that the boycott is clearly geographically limited: 90% of newsagents in Lancashire and 88% of newsagents in Cheshire report selling The Sun. Asked about the number of copies of The Sun the newsagent sold on an average weekday, 34% of newsagents who did not sell The Sun mentioned the boycott unprompted. One newsagent went on to explain:

“It’s Liverpool, innit?” was a common theme when interviewing newsagents’ about how many copies of The Sun they sold. The top panel in Figure 2 displays the estimated number of newspaper sales on an average weekday per newsagent in Merseyside compared with adjacent counties. With an estimated six copies sold per newsagent per day, sales in Merseyside are only around one third of those in Cheshire and one fourth of those in Lancashire.

Figure 2.

Estimated Extent of the Boycott in Merseyside and Adjacent Counties

Note: Top: Average number of papers sold per newsagent per county (source: original newsagents telephone survey, N = 165 shops); whiskers show 95% confidence intervals. Bottom: Location of boycotting shops (source: https://totaleclipseofthesun.org/shops).

The bottom panel of Figure 2 then reports shops boycotting The Sun in Merseyside according to a webpage associated with the “Total Eclipse of the S*n”-campaign. Both independent data sources provide complementary information on the extent of the boycott and show that the boycott is strong across Merseyside—strongest in its core—and does not significantly extend to areas outside of Merseyside.

Even after The Sun’s unreserved apology in 2012 under the headline “Hillsborough: The real truth,” which admitted that their reporting on Hillsborough was the “gravest error” in the tabloid’s history and acknowledged that “the people of Liverpool may never forgive us for the injustice we did to them” (Moriarty, Veevers, and Dunn Reference Moriarty, Veevers and Dunn2012), the boycott is ongoing to this day (Conn Reference Conn2017). In fact, a strong social norm of boycotting The Sun developed in Merseyside. The norm extends not only to boycotting the newspaper itself but also to interviews by public figures such as Merseyside MPs and celebrities who are publicly sanctioned when breaking the norm (The Liverpool Echo 2011; Thorp Reference Thorp2018). Due to the UK’s reliance on newsagents for newspaper sales, before the advent of the Internet in the 2000s, norm violations were easy to police and the initial boycott easier to enforce. Three newsagents interviewed mentioned unprompted that they were not selling the paper because they were worried about customers’ reactions: “We stopped selling The Sun because we don’t want any trouble—people were coming in and complaining.” One newsagent reported that last time they tried selling The Sun, people were “throwing things.” There is also evidence that the boycott led to habit formation that lasted into the Internet age. To get a better understanding of how often people in Liverpool access The Sun online, we report Googletrends data (more information: Appendix A.1), which is available at the city level in England from 2004 until today.

Googletrends displays the relative amount of searches for a respective term, meaning that we can not know how many people in Liverpool searched for The Sun on Google but only the relative number in relation to the region where most people searched (Wolverhampton = 100%). In Liverpool we find by far the lowest search amount in any British city, with a 30% search share. Even in urban, cosmopolitan areas such as London, Oxford, or Cambridge the search amount is still around 50%. Overall, this suggests we have little reason to question that people from Merseyside bypass the boycott of The Sun or seek access to The Sun via the Internet, even today.

The occurrence of the Hillsborough disaster, thus, gives us the rare opportunity to identify the causal effect of a sustained media boycott on attitudes toward the EU because the circulation of the most important Eurosceptic tabloid was significantly reduced due to a sporting disaster, which was unrelated to the tabloid’s EU coverage. Readers did not choose to stop reading The Sun due to its EU coverage but due to a clear cause, which is exogenous to The Sun’s anti-EU campaign. Thus, our research design addresses the methodological issues of selection and reverse causation discussed above.

The Sun’s EU coverage

The Australian-born media mogul Rupert Murdoch bought the British newspaper The Sun in 1969 and turned it into a “red top” tabloid paper (Rooney Reference Rooney, Sparks and Tulloch2000), directly competing for readers with the Daily Mirror, a title that dominated the tabloid market in the UK in the 1960s and 1970s. The British newspaper market can broadly be divided into two sections: “Quality papers,” often referred to as “broadsheets,” such as The Guardian and The Times, and “tabloids,” which are defined by their sensationalist coverage and eye-catching title pages. By the end of the 1970s, The Sun had overtaken The Mirror as the most widely read tabloid in the UK (Johansson Reference Johansson2007). In 1992, The Sun had a daily circulation of around 3.6 million and was read by around 10 million individuals (Rooney Reference Rooney, Sparks and Tulloch2000). At the end of the 1980s, The Sun and The Mirror combined sold more copies than all other English newspapers taken together (Johansson Reference Johansson2007).

However, in contrast to its main competitor, The Mirror, The Sun took a strong negative editorial stance on the European Union during the 1990s and 2000s (see Figure A.4 and Figures A.5 in the Appendix for the number of articles and proportion of editorials that contain EU-specific search terms). As Nigel Farage commented in a recent BBC interview, “I think Murdoch helped to create an environment in which Brexit could happen with the Sun’s pretty constant Eurosceptic criticism” (Roberts Reference Roberts2020).

In Table 1 we display a comprehensive content analysis of a random sample of editorials published in The Sun and The Mirror that contained search terms associated with the “European Union.”Footnote ⁴ Between 1996 and 2016, the period for which editorials are available in the Factiva database, 92% of The Sun’s editorials displayed a negative tone toward European integration and 80% were classified as “Eurosceptic,” based on the definition by Vasilopoulou (Reference Vasilopoulou2013) provided to coders (see Appendix A.3.1). This overwhelmingly negative slant of The Sun compares with the relatively neutral to positive slant that is visible in The Daily Mirror throughout the same period. Only 10% of The Mirror’s editorials were classified as “negative” in tone toward European integration by coders and only 6% could be classified as “Eurosceptic.”Footnote ⁵

Table 1.

Editorial Slant of the Sun and the Mirror, 1996–2016

While The Sun’s Online Archive only starts in 1996, in Appendix Figure A.8 we present qualitative evidence that The Sun’s Eurosceptic coverage was pronounced around the time of the Hillsborough disaster in the early 1990s when the paper opposed then Commission President Jacques Delors in his feud with British Prime Minister Margaret Thatcher about further European integration, British participation in monetary union, and British contributions to the EC budget. Now famous articles and editorials from 1989 and 1990, the period directly following the Hillsborough disaster, are shown in Figure 1 and A.8 in the Appendix.

Moreover, The Sun became famous for inventing and spreading so-called Euromyths, some of the most famous being that Brussels was trying to ban “bendy bananas” and regulate the shape of cucumbers (see Figure A.9 in the Appendix for a famous Sun story). All stories portray EU bureaucrats as out-of-touch and trying to impose unnecessary red tape on Britain. The persistence of Euromyths among the British public was a problem important enough that the European Commission dedicated an entire website to debunking these myths during the 2016 EU referendum campaign (Hobolt and Tilley Reference Hobolt and Tilley2014). While there are other Eurosceptic papers in the UK, notably the Daily Mail and the Daily Telegraph, The Sun has by far the highest circulation numbers. As Figure A.2 in the Appendix shows, in 1992 The Sun had around 3.6 million readers compared with the Mail’s 1.7 million readers and the Telegraph’s 1 million readers. Moreover, the class appeal of Eurosceptic papers in the UK is markedly different. The Sun’s readership is significantly more working class than the readership of other papers (Ladd and Lenz Reference Ladd and Lenz2009; Rooney Reference Rooney, Sparks and Tulloch2000; see also Figure A.15 in the Appendix). During most of the period we study, The Sun supported the Conservative party under Margaret Thatcher (PM from 1979–1990) and John Major (PM from 1990–1997). While the tabloid switched support to New Labour under Tony Blair and Gordon Brown from 1997 until the 2010 General Election, it remained steadfast in its Eurosceptic slant and anti-EU coverage throughout UK Labour’s last period in office (Ladd and Lenz Reference Ladd and Lenz2009; Roberts Reference Roberts2020).

The Sun was a major media player in the EU referendum campaign of 2016 when it forcefully advocated for a “Leave” vote (see Figure A.7). A comprehensive analysis of EU referendum media coverage shows that The Sun was classified as one of only two papers in the UK (the other being the Daily Mail) that was both Eurosceptic in its positioning and had a large reach and volume, meaning it was read by a large proportion of the electorate (Levy, Aslan, and Bironzo Reference Levy, Aslan and Bironzo2016, 17). Importantly, The Sun published more than twice as many articles on the referendum than the second most important tabloid, the Mirror, which took a pro-EU stance (Levy, Aslan, and Bironzo Reference Levy, Aslan and Bironzo2016, 12). Emphasizing the papers’ perceived contribution to Brexit, the editor of The Sun, Tony Gallagher, texted the Guardian Newsroom on the morning after the referendum with the words “So much for the waning power of the print media” (Martinson Reference Martinson2016).

Research Design

The unexpected occurrence of the Hillsborough disaster allows us to estimate the causal effect of a widespread, but geographically restricted, boycott of the most important Eurosceptic tabloid newspaper in the UK, caused by a plausibly exogenous event, on attitudes toward leaving the EU. In our framework, all parliamentary constituencies that happen to be located within Merseyside county would be assigned to treatment, the tabloid boycott. Our main analyses are therefore “intent-to-treat” analyses. We conceptualize the boycott as a large number of shops refusing to sell the paper and a majority of citizens refusing to read The Sun. Both dynamics are strongly and positively correlated. In our data we do not observe evidence consistent with a displacement mechanism: shops in Merseyside that continue to sell The Sun do not sell more copies than shops in places where the boycott is not operational. In auxiliary analyses we therefore measure the extent of today’s boycott via two distinct but complementary proxies: the number of stores that participate in the boycott according to a list provided on the “Total Eclispe of the S*n” campaign website that we scraped from the Internet and geolocated within parliamentary constituenciesFootnote ⁶ and based on the proportion of shops boycotting The Sun as recorded in our newsagents survey.

Given the strong anti-EU stance of The Sun, we expect that due to the boycott induced by the Hillsborough disaster, Euroscepticism should decrease in Merseyside compared with a counterfactual where Hillsborough would not have happened. To construct this credible counterfactual, we rely on a difference-in-differences design (DiD) (Angrist and Pischke Reference Angrist and Pischke2009; Dunning Reference Dunning2012), assuming that Euroscepticism in Merseyside would have continued on a similar trend to the rest of Northern England were it not for The Sun boycott directly induced by the newspaper’s libellous reporting on the Hillsborough disaster.

Estimation

To estimate the DiD, we allocate respondents to the treatment group if they reside in parliamentary constituencies within Merseyside and to the control group if they reside in the remaining Northern English parliamentary constituencies. The reason that we define other Northern English constituencies as the control in our main specification is that they were subject to similar macroeconomic and socioeconomic trends over period that we study (Wilks-Heeg Reference Wilks-Heeg and Munck2003). Regions such as London and the South of England had seen faster economic growth in the 1980s and 1990s than the North of England. Note, however, that our findings are robust to including all of England as a control group (Appendix A.7).

We apply a two-way fixed effects specification, which allows us to adjust for any time-constant differences across constituencies:

(1) $$ \mathrm{leaving}\;{\mathrm{EU}}_{i,c,t}={\alpha}_c+{\gamma}_t+{\delta}_{\mathrm{DID}}{T}_{c,t}+{\varepsilon}_{i,c,t}, $$

where Leaving EU_i,c,t is respondent i’s support for leaving the EU in constituency _c at year _t ; α_c is a constituency fixed effect that rules out omitted variable bias from unobserved constituency characteristics that are invariant over our study period; γ_t are time fixed effects (year, quarter) that control for common factors changing across time; T_i,c,t is our binary treatment indicator, that equals 1 for Merseyside after the Hillsborough disaster; and $ {\varepsilon}_{i,c,t} $ is the error term. The term δ_DID is the estimand of interest, which identifies the effect of Hillsborough on Euroscepticism in Merseyside. Because the sampling frame of the survey is stratified by constituency, we cluster our standard errors at the constituency level.Footnote ⁷

As a robustness test, we use constituency-specific linear time trends instead of the simpler constituency and time fixed effects specification, outlined above. The model we estimate is as follows:

(2) $$ {\displaystyle \begin{array}{l}\mathrm{leaving}\;{\mathrm{EU}}_{i,c,t}={\alpha}_c+{\gamma}_t+{\alpha}_c\times {\gamma}_t+{\delta}_{\mathrm{DID}}{T}_{c,t}+{\varepsilon}_{i,c,t}\end{array}}. $$

This allows treatment and control constituencies to follow different trends (Angrist and Pischke Reference Angrist and Pischke2009, 238). Furthermore, we conduct analyses using alternative sample compositions (Appendices A.6 and A.7), investigate potential spillover effects to adjacent constituencies (Appendix A.8), conduct placebo tests (Appendix A.9), use matching techniques (Appendix A.10), and provide additional information and data that helps us appreciate the exclusion restriction to further substantiate the robustness of our empirical findings.

Our attitudinal analyses are based on the long-running and high-quality British Social Attitudes (BSA) Survey—an annual cross-sectional survey of public opinion toward social and political issues in Britain (National Centre for Social Reserach 2004).Footnote ⁸ We rely on the BSA Survey because it is the only survey in the UK that covers a sufficiently long period before and after the Hillsborough disaster and provides information about the location of the interview at the constituency level. We cover the years from 1983 to 2004, the last year in which parliamentary constituency identifiers are included in the BSA, allowing us to match respondents to the area in which they live. From 2005 onward, the BSA no longer includes any location identifiers smaller than the subregion.Footnote ⁹ Of the 35,204 BSA respondents, 908 live in one of the 15 parliamentary constituencies within Merseyside and were directly exposed to the “Sun” boycott.Footnote ¹⁰ We measure Euroscepticism by relying on the question asking respondents whether “Britain should continue its EEC/EU membership.” Our dependent variable Leaving EU is then coded 1 if respondents answered that Britain should withdraw from/leave the EEC/EU and 0 otherwise.Footnote ¹¹ As we use the BSA Euroscepticism measurement instrument over a 30-year period, concerns over measurement error linger. In Appendix A.4 we validate the measurement instrument by reporting a strong correlation between national trends in Euroscepticism as recorded in the BSA and the most frequently used measure based on Eurobarometer data.

Because we are dealing with repeated cross-sectional data, we control for respondents’ gender, age, education, ethnicity, self-reported social class, and party identification. As the BSA reports the interview dates for each respondent, we can directly identify which respondents were interviewed before and after the 19th of April 1989—the day The Sun published its first of several slanderous front pages on the Hillsborough Disaster.

Discussion and Conclusion

Evidence from an exogenously induced boycott of the most important Eurosceptic newspaper—The Sun—in Merseyside as a consequence of the paper’s reporting on the Hillsborough sporting disaster—caused a decrease of Euroscepticism in Merseyside. Consistent with our hypothesis that the decline in Euroscepticism in Merseyside post-1989 was driven by The Sun boycott, treatment effects are stronger among generations that came politically of age during the boycott and among unskilled and semiskilled workers, the social group that was most likely to read The Sun before Hillsborough. The effects we identify cannot be explained by differential trends in party preferences between Merseyside and other Northern English counties, nor are they likely to have resulted from differential access to EU structural funds or differential effects of globalization on offshorability.

Therefore, our study makes an important contribution to our understanding of the long-term effects of sustained media campaigns on public opinion. The study of over-time processes and temporal dynamics in media persuasion research is “in need of considerably more theoretical and empirical attention” (Leeper and Slothuus Reference Leeper, Slothuus, Grofman, Suhay and Trechsel2020), and instances that allow for such study are rare. Besides our contribution to the over-time study of media effects, we also address another related challenge of research on the media and public opinion—namely, that most studies can only look at the effects of a specific article or news story rather than the effects of an entire media campaign over an extended period. As former Conservative Chancellor Michael Heseltine said in a recent BBC interview speaking about the Sun’s anti-EU campaign, “That drip drip drip of European poison decade after decade had a most unfortunate effect on British public opinion” (Roberts Reference Roberts2020). No matter where one stands on the normative question, it is not inconceivable that as a discipline we perceive media effects to be small because we usually study small, one-off, interventions.

To what extent are the results generalizable to other contexts beyond the Hillsborough case, given that our estimates are local to Merseyside and the North of England? While generalizability must ultimately remain an empirical question, in this paper we clearly outline the scope conditions that we think need to hold for media campaigns to result in large and lasting opinion change. In highly saturated and polarized campaign environments (Kalla and Broockman Reference Kalla and Broockman2018), on highly salient issues, and where strong counterframes are available (Chong and Druckman Reference Chong and Druckman2007), we would expect the media to have minimal or, at best, small effects. We would expect substantively large effects where political contexts allow for sustained and one-sided media coverage on emerging issues. Moreover, we think that tabloid media outlets can be particularly influential if they decide to take a stance on politics because readers are likely to select into consumption for entertainment purposes (Arceneaux and Johnson Reference Arceneaux and Johnson2013). Thus, tabloids overcome the problem that those individuals who should be most likely to receive persuasive content are least likely to change their mind because they are highly attentive to politics in the first place (Zaller Reference Zaller1992).

One counterfactual worth considering when thinking about the generalizability of our results is whether The Sun boycott would have produced equally large effects had it happened for instance in Hampshire, in the South of England, as opposed to Merseyside, in the North of England. One key question is whether former “Sun” readers would have substituted their media diets with equally Eurosceptic papers or whether they would have followed Merseyside’s lead on substituting a Eurosceptic with a pro-EU tabloid. Because we think that substitution occurred based on cultural, not political preferences (Rooney Reference Rooney, Sparks and Tulloch2000), we would expect that we should have seen similar effects in places that have a similar class composition of newspaper readership.

While instances that allow for the causal study of a sustained one-sided media campaign are rare (Leeper and Slothuus Reference Leeper, Slothuus, Grofman, Suhay and Trechsel2020), that does not mean that sustained one-sided media campaigns are rare per se. Besides the Murdoch-owned Eurosceptic tabloid press in the United Kingdom, important cases that immediately come to mind are the emergence of another Murdoch-owned medium, Fox News, in the United States (DellaVigna and Kaplan Reference DellaVigna and Kaplan2007), Berlusconi-owned TV channels in Italy (Mastrorocco and Minale Reference Mastrorocco and Minale2018), an Adelson-owned newspaper in Israel (Grossman, Margalit, and Mitts Reference Grossman, Margalit and Mitts2020), and Blocher-owned newspapers in Switzerland (Spirig Reference Spirig2020). These outlets all push clear political agendas over a sustained period—they raise the salience of specific issues and provide a strong frame with which to interpret them. Whether these “issue entrepreneurs” (de Vries and Hobolt Reference de Vries and Hobolt2020) are ultimately successful also depends on whether other actors engage in time and counter the frames provided. As George Osborne, the former chancellor and one of the key government figures in the “Remain” campaign wrote in 2018, “We were too late in the day trying to explain some of the benefits of EU membership” (BBC 2018).

Beyond adding to our understanding of media effects on public opinion in general, what does this study tell us about the rise of Euroscepticism and the 2016 Brexit vote in particular? Although our main results focus on the effects of the boycott on public opinion toward leaving the EU, official counting area data from the 1975 and 2016 EU referendums also suggest that The Sun boycott might have decreased the “Leave” vote share in Merseyside in the 2016 EU referendum. Because this auxiliary analysis covers a longer period, we account for potential time-variant confounders such as changes in education levels and EU migration. Combining the analysis of the public opinion data spanning 30 years and the data on the referendum votes in 1975 and 2016 in a DiD framework, our study indicates that sustained media campaigns on emerging issues can have large, lasting, and ultimately consequential effects on public opinion and public policy.

In addition to the well-researched economic and social factors that have contributed to Eurosceptic opinion and to the Brexit vote in 2016 (Becker, Fetzer, and Novy Reference Becker, Fetzer and Novy2017; de Vries Reference de Vries2018), we show that, at least in part, public opinion and policy-relevant public decisions were endogenous to tabloid media reporting. While this result may not be counterintuitive or come as a big surprise to those who follow British politics, it is one thing to suspect that a causal relationship exists and another to provide empirical evidence consistent with this assumption. Moreover, our article shows that the decline of Euroscepticism in Merseyside following The Sun boycott largely reflects a decrease in Euroscepticism among unskilled and semiskilled working-class voters, who made up a large share of Sun readers before the disaster. This finding is consistent with Ladd and Lenz’s (Reference Ladd and Lenz2009) study of the effects of the Sun’s endorsement switch from Conservatives to Labour at the 1997 General Election, where persuasive effects were also more pronounced among working-class “Sun” readers. By documenting the role of the tabloid media in affecting attitude change toward European integration among working-class voters, we highlight an important nonstructural factor that contributed to the increase in Euroscepticism. This does not mean that EU immigration, regional inequalities, or austerity did not matter or that The Sun caused Brexit, but this study provides evidence that the tabloid press played an important role in shaping support for “Leave” among working-class voters.