Maxwell McCombs - Setting the Agenda

Unemployment and urban congestion, especially in the old quarter of the city during the weekends, topped the public agenda in Pamplona, Spain, during the spring of 1995. 23Comparisons between all six major concerns on the public agenda and local news coverage in the preceding fortnight found high degrees of correspondence. The match with the dominant local daily newspaper was +0.90; with the second Pamplona daily, +0.72; and with television news, +0.66.

Agenda setting also occurred in a 1986 mayoral election in Machida City, a municipality of 320,000 residents in the Tokyo metropolitan area. 24Comparison of the public agenda, which had seven issues in all, with the coverage of the four major newspapers serving Machida City, yielded a modest, but significant, correlation of +0.39. Although there were no significant variations in the strength of this relationship among persons differing in age, sex, or level of education, Chapter 5will take up a psychological factor that does provide an explanation for this relatively low correlation.

Local agenda-setting effects also were found in the 1997 legislative elections in the Buenos Aires metropolitan area. 25In September, the correlation for the top four issues of the day was +0.20 between the public agenda and the combined issue agenda of five major Buenos Aires newspapers. However, as election day approached in October, the correspondence between these agendas for the top four issues soared to +0.80, an increase that suggests considerable learning from the news media in the closing weeks of the election campaign.

Additional evidence of significant agenda-setting effects in Argentina was found during the 1998 primary election held to select the presidential candidate for a major political coalition. For the six major issues of the day, the correspondence between the public agenda at the time of the election and the newspaper agenda of the previous month was +0.60. For television news, the correspondence was even higher, +0.71. 26

Similar evidence about the variable impact of news coverage on the trends in public opinion comes from the individual analyses of eleven different issues in the United States during a 41-month period in the 1980s. 27In each of these eleven analyses, the media agenda is based on a mix of television, newspapers and news magazines. The public agenda is based on thirteen Gallup polls that asked Americans to name the most important problem facing the country. Two patterns are evident in these analyses. First, all except one of the correlations summarizing the match between the media agenda and the public agenda are positive. The median correspondence between these agendas is +0.45. The negative match for morality is easy to explain because morality is a topic seldom broached in the news media.

For the other ten public issues during this period in the 1980s, the positive correlations suggest some degree of agenda-setting influence. However, a pattern of considerable variability in the strength of the association between the two agendas is also apparent. This calls our attention to factors other than media coverage that influence the public’s perception of what are the most important issues of the day, and Chapters 4and 5will discuss a variety of psychological and sociological factors that are significant in the public’s daily transactions with the communication media and the issues of the day. These factors can enhance or constrain the degree of media influence.

The evidence reviewed here, plus many other field studies conducted around the world, corroborate a cause-and-effect relationship between the media agenda and the public agenda. The initial necessary condition for demonstrating causality is a significant degree of correlation between the presumed cause and its effect, a condition met by hundreds of agenda-setting studies worldwide.

A second necessary condition for demonstrating causality is time-order. The cause must precede the effect in time. Even the initial Chapel Hill study was careful to juxtapose the results of the public opinion poll measuring public concern about the issues of the day with the content of the news media in the weeks preceding the interviewing as well as with the days concurrent with the interviewing. 28Evidence of agenda-setting effects in the two subsequent US presidential elections was based on panel studies. There were two waves of interviewing and content analysis during June and October in Charlotte during the 1972 presidential election, plus a third wave of interviews immediately following the election. 29During the 1976 presidential election there were nine waves of interviewing from February to December and content analyses of local newspapers and national television news across the entire year in three different communities. 30Both of these panel designs allowed detailed tests of the time-order involved in the relationship between the media and public agendas.

Other evidence of agenda-setting effects reviewed here from a variety of non-election settings also involves longitudinal research designs that allowed tests of the time-order involved in the relationship between the media and public agendas. The examination of the civil rights issue in the United States spanned twenty-three years. 31There are eleven replications of this type of single-issue analysis based on a 41-month period during the 1980s, 32and an intensive week-by-week examination of five individual issues in Germany during 1986. 33Eight local issues were analysed, both in the aggregate and individually, in Louisville during an eight-year period. 34

All of this evidence about agenda-setting effects is grounded in the ‘real world’ – public opinion surveys based on random samples of the public and content analyses of actual news media. This evidence illustrates agenda-setting effects in a wide variety of situations, and it is compelling for the very reason that it portrays public opinion in the real world. But these réalité portraits of public opinion are not the best evidence for the core proposition of agenda-setting theory that the media agenda has a causal influence on the public agenda because these measures of the media and public agendas are linked with numerous uncontrolled factors.

The best, most unequivocal evidence that the news media are the cause of these kinds of effects comes from controlled experiments, a setting where the theorized cause can be systematically manipulated, subjects randomly assigned to various versions of this manipulation, and systematic comparisons made among the outcomes. Evidence from experiments provides the third and final link in the chain of causal evidence that the media agenda influences the public agenda, demonstration of a direct functional relationship between the content of the media agenda and the response of the public to that agenda.

Changes in the salience of defence preparedness, pollution, arms control, civil rights, unemployment, and a number of other issues were produced in the laboratory among subjects who viewed versions of TV news programmes that had been edited to emphasize a particular public issue. 35A variety of controls ascertained that changes in the salience of the manipulated issue were, in fact, due to exposure to the news agenda. For example, in one experiment, subjects who viewed TV news programmes emphasizing defence preparedness were compared to subjects in a control group whose news programmes did not include defence preparedness. The change in the salience of this issue was significantly higher for the test subjects than for the subjects in the control group. In contrast, there were no significant differences between the two groups from before to after viewing the newscasts for seven other issues.

Bringing the cause-and-effect evidence of the laboratory up to date, two experiments investigated the agenda-setting effects of online news on personal agendas. One experiment compared the salience of international issues among readers of the print and online versions of the New York Times . Although there were stronger effects for the print version of the newspaper, subjects exposed to both versions were significantly different from a control group with no exposure to the New York Times . Opening the door to further exploration of the agenda-setting process, these experimenters argued that ‘contemporary incarnations of internet news are subtly, but consequentially, altering the way that the news media set the public’s agenda’. 36Another experiment exposed participants to either a CNN newscast or the CNN news site and then measured their recall of the top stories and their rankings of issue importance. 37The influence of television news was stronger than the impact of the web on viewers. Arguably, the format of web pages does not always contain distinctive salience cues about the media agenda.