Vivianne H.M. Visschers

Probability Information in Risk Communication : A Review of the Research Literature

Communicating probability information about risks to the public is more difficult than might be expected. Many studies have examined this subject, so that their resulting recommendations are scattered over various publications, diverse research fields, and are about different presentation formats. An integration of empirical findings in one review would be useful therefore to describe the evidence base for communication about probability information and to present the recommendations that can be made so far. We categorized the studies in the following presentation formats: frequencies, percentages, base rates and proportions, absolute and relative risk reduction, cumulative probabilities, verbal probability information, numerical versus verbal probability information, graphs, and risk ladders. We suggest several recommendations for these formats. Based on the results of our review, we show that the effects of presentation format depend not only on the type of format, but also on the context in which the format is used. We therefore argue that the presentation format has the strongest effect when the receiver processes probability information heuristically instead of systematically. We conclude that future research and risk communication practitioners should not only concentrate on the presentation format of the probability information but also on the situation in which this message is presented, as this may predict how people process the information and how this may influence their interpretation of the risk.

How a Nuclear Power Plant Accident Influences Acceptance of Nuclear Power: Results of a Longitudinal Study Before and After the Fukushima Disaster

Major nuclear accidents, such as the recent accident in Fukushima, Japan, have been shown to decrease the publics acceptance of nuclear power. However, little is known about how a serious accident affects peoples acceptance of nuclear power and the determinants of acceptance. We conducted a longitudinal study (N= 790) in Switzerland: one survey was done five months before and one directly after the accident in Fukushima. We assessed acceptance, perceived risks, perceived benefits, and trust related to nuclear power stations. In our model, we assumed that both benefit and risk perceptions determine acceptance of nuclear power. We further hypothesized that trust influences benefit and risk perceptions and that trust before a disaster relates to trust after a disaster. Results showed that the acceptance and perceptions of nuclear power as well as its trust were more negative after the accident. In our model, perceived benefits and risks determined the acceptance of nuclear power stations both before and after Fukushima. Trust had strong effects on perceived benefits and risks, at both times. Peoples trust before Fukushima strongly influenced their trust after the accident. In addition, perceived benefits before Fukushima correlated with perceived benefits after the accident. Thus, the nuclear accident did not seem to have changed the relations between the determinants of acceptance. Even after a severe accident, the public may still consider the benefits as relevant, and trust remains important for determining their risk and benefit perceptions. A discussion of the benefits of nuclear power seems most likely to affect the publics acceptance of nuclear power, even after a nuclear accident.

Impact of Knowledge and Misconceptions on Benefit and Risk Perception of CCS

Carbon Dioxide Capture and Storage (CCS) is assumed to be one of the key technologies in the mitigation of climate change. Public acceptance may have a strong impact on the progress of this technology. Benefit perception and risk perception are known to be important determinants of public acceptance of CCS. In this study, the prevalence and effect of cognitive concepts underlying laypeoples risk perception and benefit perception of CCS were examined in a representative survey (N=654) in Switzerland. Results confirm findings from previous qualitative studies and show a quantification of a variety of widespread intuitive concepts that laypeople hold about storage mechanisms as well as about leakage and socioeconomic issues, which all appeared to influence risk perception and benefit perception. The perception of an overpressurized reservoir and concerns about diffuse impacts furthermore amplified risk perception. Appropriate images about storage mechanisms and climate change awareness were increasing the perception of benefits. Knowledge about CO2 seemed to lower both perceived benefits and perceived risks. Implications for risk communication and management are discussed.

Consumers’ knowledge about climate change

Several studies have unveiled various misconceptions about climate change that the public holds, for instance, confusion about climate change and ozone depletion. However, so far, there has been no uniform and standardized way to measure climate-related knowledge, which complicates comparisons between different countries or samples. To develop an extensive knowledge scale, we therefore examined the Swiss public’s understanding of climate change in a mail survey and related this scale to attitudes toward climate change. We thereby aimed to consider a broad range of climate-related knowledge, namely physical knowledge about CO2 and the greenhouse effect, knowledge about climate change and its causes, knowledge about the expected consequences of climate change, and action-related knowledge. The questionnaire included items of different degrees of difficulty, ranging from knowledge that is covered by newspapers to experts’ knowledge. Our findings indicate that people still hold several misconceptions, although people’s knowledge related to CO2 seems to have increased compared to previous studies. Of all knowledge subscales, knowledge about climate change and causes was most strongly related to attitudes toward climate change.

Affective Imagery and Acceptance of Replacing Nuclear Power Plants

This study examined the relationship between the content of spontaneous associations with nuclear power plants and the acceptance of using new-generation nuclear power plants to replace old ones. The study also considered gender as a variable. A representative sample of the German- and French-speaking population of Switzerland (N= 1,221) was used. Log-linear models revealed significant two-way interactions between the association content and acceptance, association content and gender, and gender and acceptance. Correspondence analysis revealed that participants who were opposed to nuclear power plants mainly associated nuclear power plants with risk, negative feelings, accidents, radioactivity, waste disposal, military use, and negative consequences for health and environment; whereas participants favoring nuclear power plants mainly associated them with energy, appearance descriptions of nuclear power plants, and necessity. Thus, individuals opposing nuclear power plants had both more concrete and more diverse associations with them than people who were in favor of nuclear power plants. In addition, participants who were undecided often mentioned similar associations to those participants who were in favor. Males more often expressed associations with energy, waste disposal, and negative health effects. Females more often made associations with appearance descriptions, negative feelings, and negative environmental effects. The results further suggest that acceptance of replacing nuclear power plants was higher in the German-speaking part of the country, where all of the Swiss nuclear power plants are physically located. Practical implications for risk communication are discussed.

Organic Tomatoes Versus Canned Beans How Do Consumers Assess the Environmental Friendliness of Vegetables

The assessment of a food product’s environmental friendliness is highly challenging for consumers because such an assessment requires the consideration of various product characteristics. Furthermore, products often show conflicting features. This study uses a choice task and a questionnaire to examine how consumers judge the environmental friendliness of several vegetables. The consumers’ assessment is compared with life cycle assessment (LCA) results, which represent the overall environmental impact of a product throughout its lifespan. In contrast to the LCA, consumers consider transportation distance rather than transportation mode and perceive organic production as very relevant for the environmental friendliness. Furthermore, consumers assess the environmental impact of packaging and conservation as more important than the LCA results show. Findings also suggest the current product information for vegetables is insufficient for judging their environmental friendliness. Implications for information campaigns and ecological food labeling are discussed.

Public Perception of Climate Change: The Importance of Knowledge and Cultural Worldviews.

The importance of knowledge for lay peoples climate change concerns has been questioned in recent years, as it had been suggested that cultural values are stronger predictors of concern about climate change than knowledge. Studies that simultaneously measured knowledge related to climate change and cultural values have, however, been missing. We conducted a mail survey in the German-speaking part of Switzerland (N = 1,065). Results suggested that cultural worldviews and climate-related knowledge were significantly related with peoples concern about climate change. Also, cultural worldviews and climate-relevant knowledge appeared important for peoples willingness to change behaviors and to accept climate change policies. In addition, different types of knowledge were found to have different impacts on peoples concern about climate change, their willingness to change behaviors, and their acceptance of policies about climate change. Specifically, causal knowledge significantly increased concern about climate change and willingness to support climate-friendly policies. We therefore concluded that risk communication should focus on causal knowledge, provided this knowledge does not threaten cultural values.

Applying the evaluability principle to nutrition table information. How reference information changes people's perception of food products.

Consumers often neglect or misinterpret nutrition table information. We argue in this paper that this can be explained by the evaluability principle, which posits that peoples evaluation of a product corresponds to a greater degree with the products actual value when people receive reference information about the product than when they do not get this information. We tested this assumption concerning nutrition table information in two studies. In Study 1, respondents received one of six nutrition tables that differed on reference and summary information about either yogurt or chocolate. In the second study, we compared three nutrition tables from the previous study, as applied to either a low nutritional value yogurt or a high nutritional value yogurt. Participants were asked to rate the attractiveness and perceived healthiness of the product in both studies. Results indicated that reference information can change peoples product perception. This seems to depend, however, on the products nutritional value and on peoples primary connotation for the product. In sum, the evaluability principle can explain peoples perception of a food product. A nutrition table that is adapted to this principle appears to influence peoples product perception so that it becomes more in line with its nutritional value. Implications for practice and further research are given.

Affect-inducing risk communication: current knowledge and future directions

Affect appears to have a central role in people’s risk perception and decision-making. It is, therefore, important that researchers and communicators know how risk communication can induce affect or more specific emotions. In this paper, several studies that examined affect-inducing cues presented in and around risk communication are discussed. We thereby distinguish between integral affect induction, meaning through the risk message, and incidental affect induction, which occurs unintentional through the risk communication context. The following cues are discussed: emotion induction, fear appeals, outrage factors, risk stories, probability information, uncertainty information and graphs and images. Relatively few studies assessed the effect of their risk communication material on affect or specific emotions. Incidental affect induction appeared to occur more often than expected based on its factual content. Risk communication easily seems to induce affect incidentally and, thus, may be difficult to control. We, therefore, argue that incidental affect induction is more influential than integral affect induction. Implications for further research and risk communication in practice are given. Based on this overview, we strongly suggest considering and empirically assessing the affect-inducing potential of risk communication formats and content during their development and evaluation.

Alternatives to the use of antimicrobial agents in pig production: A multi-country expert-ranking of perceived effectiveness, feasibility and return on investment

Nineteen alternatives to antimicrobial agents were ranked on perceived effectiveness, feasibility and return on investment (ROI) from 0 (not effective, not feasible, no ROI) to 10 (fully effective, completely feasible, maximum ROI) by 111 pig health experts from Belgium, Denmark, France, Germany, Sweden and Switzerland. The top 5 measures in terms of perceived effectiveness were (1) improved internal biosecurity, (2) improved external biosecurity, (3) improved climate/environmental conditions, (4) high health/Specific Pathogen Free/disease eradication and (5) increased vaccination. The top 5 measures in terms of perceived feasibility were (1) increased vaccination, (2) increased use of anti-inflammatory products, (3) improved water quality, (4) feed quality/optimization and (5) use of zinc/metals. The top 5 measures in terms of perceived ROI were (1) improved internal biosecurity, (2) zinc/metals, (3) diagnostics/action plan, (4) feed quality/optimization and (5) climate/environmental improvements. Univariate linear regression showed that veterinary practitioners rank internal biosecurity, vaccination, use of zinc/metals, feed quality optimization and climate/environmental on average highest, while researchers and professors focused more on increased use of diagnostics and action plans. Financial incentives/penalties ranked low in all countries. Belgian respondents ranked feed quality significantly lower compared to the German respondents while reduction of stocking density was ranked higher in Belgium compared to Denmark. Categorical Principal Component Analysis applied to the average ranking supported the finding that veterinary practitioners had a preference for more practical, common and already known alternatives. The results showed that improvements in biosecurity, increased use of vaccination, use of zinc/metals, feed quality improvement and regular diagnostic testing combined with a clear action plan were perceived to be the most promising alternatives to antimicrobials in industrial pig production based on combined effectiveness, feasibility and ROI.