riskperception – modeller och principer

Riskperception – modeller och principer

The Swedish Risk AcademyAnnual MeetingMay 14, 2013

Lennart SjöbergCenter for Risk Research

Stockholm School of EconomicsSweden

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Outline

• Why study risk perception?• Experimental work• Factors in risk perception• Specifics of risk perception: example of chemicals• Trust and antagonism• Risk targets• Demand for risk mitigation• Affect (attitude) and emotions• Experts and the public• Conclusions

As you will see, my research questions the “received view” from well-known work on risk perception, critical comments are invited

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Why research on risk perception?

• Risk is a very common issue in policy deliberations

• This is true both for decision makers, experts and the public

• Several risk related issues have created great economic and political turbulence

• There is therefore a need to know more about how people perceive and react to risks

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Risk perception (RP) and risk communication (RC)

• Beliefs (”perceptions”) constitute the basis: What RC should be about

• Beliefs are both the motives for RC and targets of RC

• The sucess of RC is therefore dependent on the validity of RP models applied

Some experimental work

• Does exposure to well crafted “risk movies” lead to availability of the risks depicted, and hence to increased perceived risks– To our surprise no such effect could be found!

• A similar theme was studied in a quasi-experiment in 5 countries where we followed media reports on nuclear risks 10 years after the Chernobyl accident. Intense media attention should have increased availability and hence perceived risk. – To our surprise no such effect could be found!

Interpretation

• What looks like availability effects is really effects of new information, cp. the news about “mad cow disease” in the spring of 1996. This was NEW information and it had great RP effects.

• Just bringing up an old and well known risk does not make it see more threatening.

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Data sources (examples) from our work on risk perception surveys at the Center for Risk

Research in Stockholm• Several projects on attitudes and perceived risks with regard to

nuclear power and nuclear waste – both EU and Swedish data

• EU project on chemicals in consumer products

• Perceived risk of food, genetically modified food, alcohol and smoking

• Political and social risks of EU membership

• Perceived risks of terrorism

• Selected results from surveys will be presented, but first some experimental work on availability…

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Surveys: Factors in risk perception• ‘Interfering with nature’ is an important factor and so are moral

aspects

• Reactions to new technology are not driven by ‘novelty’ per se but by other factors, such as perceived benefit, or whether the technology brings about unique advantages and is hard to replace

• Social trust is important, but epistemic trust, trust in Science, is even more so

• Attitude or ”affect” plays an important role

• Risk sensitivity is an aspect of individual differences which is quite important – some people rate risks as large, others rate them as small

• Attitude to precautionary policy is another important factor

• Various hazards, some new (such as terrorism), require their own specific factors

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Typically social trust (in experts or organisations) has only a weak effect on perceived risk – correlations of 0.3 or less

But at the aggregate level it is easier to see a relationship.See graph based on surveys of chemical risks, next slide

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Factors beyond social trust

• Trust in science, as distinct from social trust, has a stronger effect – epistemic trust

• Level of education is also important

• Another important factor is perceived antagonism

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Effect of social trust is mediated byepistemic trust (model of nuclear waste risk)

Perceivedrisk

Epistemictrust

Risksensitivity

Socialtrust

Antagonism

R2=0.56R2=0.37

GFI=0.95, AGFI=0.93, RMSEA=0.030

-0.23

0.28

-0.50

0.12

-0.19

0.38 -0.510.35

-0.22R2=0.41

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Conclusion about trust

• Epistemic trust is more important than social trust

• The effect of social trust is mediated by epistemic trust

• In other words: trust in people and institutions is important to the extent that it promotes belief in the substance of their message

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Risk target: Whose ‘risk’ – more specifically?

• Personal and general risk differ both as to level and rank order

–General risk is important for lifestyle (smoking etc.,)

–Personal for environmental risks, and technology hazards

• Research shows that such risk ratings with a non-specified target are close to general risk

• But, general risk is not the most relevant in policy contexts

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Plot of mean general vs. mean personal risk, data from the public.

Mean personal risk

0 1 2 3 4 5 6

Mean general risk

0

1

2

3

4

5

6

y = x

Regression line

General risks rated as much larger thanpersonal risks

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Personal and general risk, alcohol

Alcohol consumption per week (corresponding to cl vodka)

<15 16-20 21-37 38-75 75+

Mean risk rating

2

3

4

5

Personal riskGeneral risk

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Personal and general risk, smoking

Number of cigarettes per day

<12 13-20 21-30 31-55

Mean risk rating

2

3

4

5

Personal riskGeneral risk

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Different dynamics of personal and general risk

• General risk is related to policy for hazards perceived to be under one’s personal control

• Personal risk is related to policy for hazards not under one’s personal control

• Examples: alcohol and nuclear power

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How important is ”risk”?

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Focus on risk – traditional approach

• People are asked to rate the ‘risk’

• It is assumed that perceived risk, as defined in this way, is the factor driving risk-related behaviour – such as demand for risk reduction

• But the assumption is usually implicit

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Risk mitigation – the problem

• What drives demand for risk reduction?

• Is perceived risk the important factor?

• If not, what factor is most important ?

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Example

• Consider the risk for a Swedish citizen, age 30–45, to

1. get a severe cold during the next 12 months

2. become infected with the HIV virus during the same time period

• Which risk is the largest?

• From which risk is it more important to be protected?

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Risk perception studies show that

• Risk and probability are closely related

• Severity and demand for risk reduction are closely related

• Risk and demand for risk reduction are only moderately related (“probability neglect”)

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Implications

• In risk communication it should be clear that the public wants to hear about severity of consequences, not so much about probabilities:

–Probability is hard to understand

–Precise estimates of very small probabilities must rely on many assumptions and are seldom very credible

• In risk perception research, it is necessary to broaden the scope – just studying ‘risk’ is not sufficient

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Individual differences in risk perception

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Distribution of the number of product types checked as risky, across all respondents.

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”Risk sensitivity” or attenuation- amplification of perceived nuclear waste risk

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The level of risk judgments varies stronglyacross individualsand is a very important explanatory factorin risk perception models:Risk Sensitivity

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Specific risk factors

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Recent EU project on perceived risks of chemicals in consumer products (extensive data collected in

the beginning of 2009)

• N=26,718• All 27 member states of the EU participated• Among other things, participants were asked: • According to what you know, which of the following

consumer products contain chemicals posing a risk to the user?

• 13 product categories were listed

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Percentage check a product category, all states

0 20 40 60 80

Toothpaste

Fabrics: Wool cotton or linen

Hair shampoo

Sunscreens

Fabrics: Synthetic fibers

Washing powder

Laundry or dishwashing detergents

Timber preservatives

Interior paints

Hair dyes

Bathroom cleaners

Bleach and heavy duty cleaners

Pesticides or herbicides

Specific reactions, not to general concept

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Comment:

”Chemicals” is a highly variable concept.

Sometimes very risky, sometimes not.

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Study of the perceived risk of terrorism

Conclusion

• Traditional explanatory factors (dread and new risk), as well as background factors, only explained 10-15 % of the variance of perceived risk

• Twice that level was reached by adding specific factors

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Emotions and affect

• “Affect” is a word with several distinct meanings: emotions or values (attitudes)

• It is necessary to clarify which one is investigated – they are psychologically quite different

• Both are related to risk perception

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Attitude (affect), trust, risk sensitivity

and attitude towards nuclear power (1991 study)

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Emotions – study of emotional reactions to a nuclear waste repository

• Two candidate municipalities, one control and a national sample

• About 800 respondents from two communities where site studies are now carried out

• Several emotions were rated, not only one

• Negative and positive emotions were rated

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Model of the attitude to a nuclear waste repository

Attitude to the

repository

Risk to the municipality

Epistemic trust

Negative emotions

Positive emotions

Socialtrust

Attitude to nuclear power

- 0.21

0.26

0.06 0.13

- 0.160.18

Model of attitude to the repository explaining 65% of the variance

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-0.12-0.61Worry

0.04-0.29Shame

0.03-0.25Guilt

0.210.57Satisfaction

-0.12-0.58Sadness

0.170.28Interest

-0.06-0.65Fear

-0.10-0.55Contempt

-0.08-0.62Anger

The anticipated emotional reaction of others to nuclear

power

Own emotional reaction to nuclear power

Emotion

Correlations between emotional reactions and the attitude to nuclear power

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Mean emotional reactions attributed to others versus own reactions

Own emotional reaction

Oth

ers’

em

oti

on

al r

eact

ion

1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.2 3.43.0

1.5

3.5

3.0

2.5

2.0

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A methodological point

• Instructions to rate “dread” do not specify WHOSE dread

• This probably leads to the interpretation to rate the emotional reactions of OTHERS

• In turn, data therefore reflect only a weak link between emotional reactions and perceived risk

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Conclusions about emotions• Specific and current emotional reactions do seem to

explain much of attitudes and policy behaviour, attitude (“affect”) somewhat less

• Compare these strong effects with the almost zero importance of anticipated ‘dread’ of others

• Both positive and negative emotions are important

• Note that ‘worry’ contributes beyond the effect of ‘fear’

• Anger seems to be more important than fear in policy contexts

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Experts versus the public

• Original work suggested, in some interpretations, that experts make ‘correct’ and ‘objective’ risk judgements used a very small group of ‘experts’ with questionable competence

• Later work with substantive experts has shown that they have similar structure of risk perception, but lower level

• Risk perception is related to experts’ field of responsibility – not to knowledge

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1 2 3 4 5

Mea

n r

atin

gs

by

mal

e ex

per

ts

0

1

2

3

4

5

Mean ratings by men, members of the public

A

1 2 3 4 5 6M

ean

rat

ing

s b

y fe

mal

e ex

per

ts

0

1

2

3

4

5

Mean ratings by women, members of the public

B

Ratings of risk dimensions of nuclear waste

by the public, and male and female experts

Expert-public difference for both genders

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0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0

Mea

n r

atin

gs

by

mal

e ex

per

ts

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

Mean ratings by female experts

No gender

difference

among experts

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-0.1 0.0 0.1 0.2 0.3 0.4

Reg

ress

ion

co

effi

cien

ts,

eng

inee

rs-0.1

0.0

0.1

0.2

0.3

0.4

Regression coefficients, public

B

0.0 0.1 0.2 0.3 0.4

Reg

ress

ion

co

effi

cien

t, e

xper

ts

-0.1

0.0

0.1

0.2

0.3

0.4

Regression coefficient, public

A

Regression coefficients in model of perceived nuclear waste risk, results from analyzing data from experts (A) and engineers (B) plotted against results from analyzing data from the public.

Very similar models for experts and the public

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Correlations between risk perception ratings and the psychometric factors (genetically modified food)

for the public and experts

-0.30-0.52-0.42-0.38Social trust

-0.08-0.27-0.31-0.24Epistemic trust

0.080.470.540.50Severity of consequences

0.380.610.560.51Immoral risk

0.080.470.530.47Interfering with nature

-0.060.310.510.44New risk

0.010.190.430.40Dread

ExpertsPublicExpertsPublicExplanatory variable

General riskPersonal risk

Experts’ risk ratings unrelated to “subjective factors,

But only for Dread and Novelty and for general risk

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Conclusion – public and experts

• Experts judge personal risk in a manner similar to the public

• However, their judgements of general risk seem to be less correlated with the ‘subjective’ factors

• Other studies have shown that personal risk is most important in policy related to technology and the environment

• Experts judge risks to be smaller when they are within their general area of responsibility

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What does our research imply for risk communication?

• Emotions are important to take into account – but not only strong fear

• Concern about ‘Interfering with Nature’ is a major factor– but not novelty of a risk

• People’s understanding and trust in science is very important– social trust is somewhat less important

• ‘Risk’ and ‘probability’ are marginal to people– they respond to notions about anticipated consequences and

whether a technology has unique advantages

• Experts are not that different from the public in how they react to hazards outside their field of responsibility

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For more information…

•See my homepage

http://www.dynam-it.com/lennart/

•Several papers and reports can be downloaded from that site