American Skeptics: How Special Interests Create Ambiguity on Climate Change

In 1895, Svante Arrhenius, a Chemistry Nobel laureate, published what may have been the first study about the greenhouse gas effect. Since then, a scientific consensus has been building around the existence of global warming and the fact that human activities are not free from blame. Despite the evidence, climate change remains a topic of great debate in the US. It is clear that scientists, the media, and special interests all influence this debate, but the specific effect of each is less obvious.

Jesse Shapiro, Professor of Economics at the University of Chicago Booth School of Business, models these agents’ interactions and uses the results to comprehend the American dialogue and disagreement on climate change. He finds that, in some cases, a balanced discussion between experts arguing for and against a policy can actually reduce the scope of information communicated to voters. Conversely, it is possible for partisan media to be surprisingly informative. Such results may in part explain the dissimilarity between the understanding of American citizens about global warming and that of people from other developed countries.

Shapiro’s model is a game wherein interest groups choose whether or not to hire experts whose views represent their own in the media, a decision that in turn conveys those views to voters, who subsequently vote to determine policy. The model assumes two competing interest groups looking to influence a particular policy and a community of experts, all of whom are available to be hired by either interest group to support its position. The press may or may not be partisan, and the voters make their decisions based on the information they receive from the press. Interest groups hire experts to persuade voters when policy decisions to be made will result in a gain or loss of value to the interest group. They are willing to invest in experts who advocate on their behalf in order to counter expert opinions that harm their interests.

Depending on the potential payoffs for each player, the game can end in an informative or uninformative equilibrium. Typically, expert opinion about a certain issue is roughly uniform. In such cases, there is little disagreement, little potential for payoff, and little incentive to campaign for a position. When there is significant disagreement and high potential payoffs for interest groups (for example, in the institution of a carbon tax), there are greater incentives to influence voters by investing in partisan expert opinion.

The author shows that the latter of these describes global warming coverage in the US media. The 1949 US Fairness Doctrine, although no longer active, set a reporting standard that each party to a debate should be permitted to present its views. For example, consider a TV debate between two scientists: One criticizes the damage done by greenhouse gas emissions; the other represents a minority interest group position in favor, say, of reducing pollution restrictions. Although the preponderance of scientific evidence supports the former argument, if both scientists perform well, the viewer will walk away thinking both positions are equally valid or confused about which is more accurate. The result is that voters are less informed about an issue around which the consensus should be high.

Evidence indicates that the news is usually informative. Shapiro shows that frequent consumers of the news are better informed about politics and science topics (e.g., Congressional activity and reasons for fracking) than infrequent consumers. This is true because, on most issues, the press informs its audience correctly, and consensus is reached quickly. One example might be the rapid movement away from nonessential chlorofluorocarbons in the 1970s, once scientists realized their ozone-depleting qualities.

There are examples, however, of times when disinformation through the press had important consequences. In 1998, for example, an article raised questions about the relationship between autism and the MMR (measles, mumps, and rubella) vaccine. In the following years, a consensus among scientists rejected that linkage, but groups that opposed the vaccines nonetheless achieved high coverage in the UK media. This coverage corresponded to a significant drop in MMR vaccinations. As a result, in 2012, measles cases in England and Wales reached their highest levels in decades.

The model helps to explain the persistence of climate change debate in the US. Those who read a daily newspaper and those who do not, regardless of political affiliation, do not display statistically significant differences of opinion when asked about the earth’s warming. The implication is that consuming news is not making people more informed about the issue. This is likely because interest groups with minority scientific views are campaigning in the media against the scientific consensus. Consequently, compared to other OECD countries that are less concerned with balanced journalism, American citizens are less inclined to accept the important anthropogenic factors of climate change.

 

Article Source: Special interests and the media: Theory and an application to climate change, Shapiro, J. M., National Bureau of Economic Research Working Paper 19807, 2014.

Feature Photo: cc/(Florence N)