Our main question

 There is evidence that opposing narratives can emerge as a natural outcome of the process through which a society forms collective beliefs [1]. Moreover, Individuals are subject to selective exposure to news and this trend has been amplified by the advent of social media [2, 3, 4]. A relevant question is, therefore, whether marginal exposure to one of two contrasting narratives can influence individual opinions in a distinct way, thus potentially constituting a relevant channel for opinion polarization. Furthermore, does this effect of narratives also spill over to opinions about policy issues that are not explicitly mentioned by the story that is being portrayed?  We find evidence of both these effects, but we additionally identify that the same narratives can affect policy opinions differently based on the social context.

 How we address the issue

The breakout of the COVID-19 pandemic represents an ideal setting to examine this issue, since in the early days of the pandemic, two prominent stories emerged to explain the origins of the disease. The Lab Narrative essentially suggested that the pandemic originated because of a human error and scientific misconduct in a laboratory in China. The Nature narrative instead described the biological and genetic origin of the disease (without explicitly attributing its cause to human actions). In this context, we conducted a survey experiment on US nationals in the early days of the COVID-19 pandemic (May 2020). Subjects were randomly exposed to one of the two alternative media-based explanations of the origin of the pandemic, to see whether these narratives could influence people’s opinions on both the origin of the pandemic and on three relevant policy issues (i.e., trade openness, climate change, and trust in science) that were not explicitly mentioned by the narratives. Considering these indirect effects allows us to explore whether COVID-19 explanations can evoke wider narratives that have an influence on policy opinions.

 Results

Narratives and causes of COVID-19

The respondents were asked to allocate 100 points among four potential causes: the virus was the result of a laboratory accident, the virus originated from a natural process, the virus was a weapon used by countries against each other, and other causes. The greater the number of points assigned to a particular cause, the stronger the belief that a cause is responsible for the emergence of COVID-19.

 As shown in Figure 1 participants responded positively to the explanations they were presented with. Specifically, those exposed to the Lab Narrative tended to allocate more points to the hypothesis that the virus originated from a lab accident. Conversely, those exposed to the Nature Narrative tended to assign more points to the hypothesis of a natural origin of the disease.

This result suggests that incremental exposure to one of the two contrasting narratives shifts beliefs in different directions, therefore representing a potential cause for polarization. We refer to this as two-sided polarization by exposure, as both narratives have an impact on beliefs, but in opposite directions.

Figure 1: Bar chart indicating the average points that respondents assigned to the listed causes of COVID-19 and their 95% confidence

Narratives and policy domains

 We measured individuals’ policy opinions using a 5-point Likert scale – in which the lower scores indicate a more positive view of foreign trade, climate change prevention, and scientific progress. Our results indicate that while the Lab Narrative has no impact on policy opinions, the Nature narrative mildly increases consensus for climate change prevention and trust in scientific progress as shown in Figure 2.

Thus, unlike beliefs regarding the causes of the pandemic, when considering policy opinions, only one narrative has a significant impact on beliefs. We therefore denote this effect of narratives as one-sided polarization by exposure.

Figure 2: This graph shows the marginal effect of the Nature Narrative on the predicted probabilities for each class of response.

Additional results: narratives and the social context

 A natural question is whether certain narratives may have a different impact based on the underlying cultural orientation. To capture these contextual features, we focus on the division between Republican- and Democratic-leaning states that is at the root of the so-called "American cultural divide"[5].

 Panels A1-A3 of Figure 3 illustrate the predicted opinions of subjects living in red and blue states regarding the three policy issues considered in the study. However, when exposed to the Lab Narrative, individuals living in Republican-leaning states were less supportive of free trade policies and climate change prevention policies than those living in Democratic-leaning states. In contrast, the effect of the Nature Narrative on the opinion gap between subjects residing in blue and red states seems to be less pronounced.

 To determine whether the effect of the two narratives on the three policy domains examined in the study is moderated by the participant’s state of residence, we compare the difference in policy opinions between individuals living in red and blue states who were not exposed to any narrative with the same difference between participants exposed to one of the two narratives.

 According to Panels B1 and B2 of Figure 3, the Lab Narrative significantly increases the gap between individuals living in Republican-leaning states and those living in Democratic-leaning states in terms of their policy preferences on foreign trade and climate change prevention. We denote this effect of narratives as polarization by social context, since the single narrative has opposing effects in different social contexts. On the contrary, the Nature Narrative has no polarizing effect on the policy opinions of Americans living in red and blue states as documented by panel B3.

Figure 3: For each treatment group, Panels A1-A3 illustrate the difference in opinions between subjects living in red and blue states. Panels B1-B3 display the causal differential effect of each treatment on the opinion gap between individuals living in red and blue states. Capped spikes indicate the 95% confidence iintervals derived from t-statistics (Panels A1-A3) and chi-square statistics (Panels B1-B3).

 References

1. Eliaz, K. & Spiegler, R. A model of competing narratives. Am. Econ. Rev. 110, 3786–3816 (2020).

2. Media bias and voting. Della Vigna, S. & Kaplan, E. The Fox News effect. Quart. J. Econ. 122, 1187–1234 (2007).

3. Bakshy, E., Messing, S. & Adamic, L. A. Exposure to ideologically diverse news and opinion on facebook. Science 348, 1130–1132 (2015).

4. Levy, R. Social media, news consumption, and polarization: Evidence from a field experiment. Am. Econ. Rev. 111, 831–70 (2021).

5.. Makowsky, M. D. Religion, clubs, and emergent social divides. J. Econ. Behavior Organ. 80, 74–87 (2011).