Risk notes

Geology 140 - Environmental Geology
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Risk Notes

Experts and the public tend to evaluate risk differently. These are the results of a 1987 study by Paul Slovic that laid the groundwork for the modern study of risk perception.

When asked to evaluate the risk of 30 common activities, people cited these factors in explaining why they believed activities to be more risky than the statistical risk of death would indicate:

Dread Factor		“Knowability” factor
Controllable	Uncontrollable	Not Observable	Observable
Not Dread	Dread	Unknown to Those Exposed	Known to those Exposed
Consequences Not Fatal	Consequences Fatal	Effect Delayed	Effect Immediate
Equitable	Not Equitable	New Risk	Old Risk
Individual	Catastrophic	Risk Unknown to Science	Risks Known to Science
Low Risk to Future Generations	High Risk to Future Generations	Example: Genetically engineered food	Example: Bees
Easily Reduced	Not Easily Reduced
Risk Decreasing	Risk Increasing
Voluntary	Involuntary
Example: X-rays	Example: Nuclear power

Source: Slovic, P., 1987, Perception of risk. Science, 236:280-285.

Risk & Social vulnerability

Disasters result from the intersection of a hazard and a societal response.
Therefore the society produces the disaster, not nature. Nature produces the hazard.
Disaster is the consequence of public policy and individual decisions.

Vulnerability is a function of

Income
Education
Race
Gender
Language isolation
Disability
Social capital

Examples

Katrina: voluntary evacuation meant only those with access to transportation escaped
2004 Tsunami - Up to 80% of those who drowned were women. In these conservative cultures, women rarely were taught to swim
Tornadoes and mobile homes - mortality is many times higher than in stick-built homes

Technology v. Social planning

Example of technological fixes:

Higher or stronger levees
Bigger dams

Examples of social planning

Zoning to prevent development in flood plain
Detailed evacuation plans, frequently practiced

If you have limited money to spend, where would you invest it?

More things that affect our perception of risk:

We tend to assess risk in two ways:
- With our analytical forebrain
- With or fight-or-flight amygdala
- They don’t always agree
Novelty-seeking personalities that seek risk
Almost everyone is bad at balancing short-term benefits vs. long-term risk
We also tend to forget that EVERYTHING carries risk, and we are balancing risk against risk