Risk Compensation

1
Risk Compensation

• Elizabeth Braun
• University of Idaho

The engineering definition of risk is
                                                  
                                                  
                                                  
                                                  
      
2
Risk Compensation

• Homeostasis
• Risk Homeostasis
• Risk Homeostasis Theory
• Opponents

3
Homeostasis

• Walter B. Cannon (1929)
• Greek words same steady
• Dynamic process
• Matches actual output to a target
• Self-correcting using negative feedback

4
Homeostasis Model
Comparator
Expected Costs and Benefits of Alternative
Temperatures
Desired (set) Temperature
Desired Adjustment a-b 0

Quality of Switch Function, Inertia
-
Temperature Reading on Thermometer
Adjustment Action
Sensitivity of Thermometer
Heating Capacity of Furnace
Resulting House Temperature
Lagged Feedback
5
Risk Homeostasis

• GSR Galvanic Skin Response
• Electrodemal response (EDR)
• change in skin conductance (electrical
  resistance)
• Measure of degree of risk, fear, anger, sexual
  feelings
• One component of polygraph

6
Risk Homeostasis

• Donald Taylors Driver study
• Accident rate per vehicle mile
• GSR rate per mile
• Average Speed
• Driver Study Correlations
• Between Accident rate per vehicle mile GSR rate
  per mile - 0.61- 0.89
• Between Accident rate per vehicle mile Average
  Speed - -0.67 - -0.74
• Between GSR rate per mile Average speed - -0.75
  - -0.92
• Drivers kept risk stable

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Risk Homeostasis Theory
Comparator
Perceived Costs and Benefits of Action
Alternatives
Target Level of Risk
Desired Adjustment a-b 0

Decision making skills
-
Adjustment Action
Vehicle handling skills
Perception skills
Perceived Level of Risk
Car Road Design
Resulting Accident Toll
Lagged Feedback
8
Risk Homeostasis Theory
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Motivating Factors

• Risky Behavior
• Expected Advantages
• Expected Costs
• Safe Bahavior
• Expected Benefits
• Expected Costs

10
Risk Homeostasis Theory
Comparator
Perceived Costs and Benefits of Action
Alternatives
Target Level of Risk
Desired Adjustment a-b 0

Decision making skills
-
Adjustment Action
Vehicle handling skills
Perception skills
Perceived Level of Risk
Car Road Design
Resulting Accident Toll
Lagged Feedback
11
Target Level of Risk

• Deliberately Pursued vs. Passively Accepted
• Long-lasting
• cultural, economy, socio-economic status,
  incentives to be accident free, occupation, age,
  gender
• Shorter-term
• Purpose, arrival urgency,
• pre-occupations, mood, fatigue, alcohol
• Momentary
• Traffic, good progress

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Risk Homeostasis Theory

• Perceived Level of Risk
• Past Experience
• Persons assessment
• Degree of confidence
• Comparator
• Just Noticeable Difference
• Immediate effects
• Long-term effects
• Risk under / over estimators

Comparator
Target Level of Risk

-
Perceived Level of Risk
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Risk Homeostasis Theory
Decision making skills

• Resulting Accident Toll
• Sum of actions
• Implications
• Accident
• Risk
• Skills

Adjustment Action
Vehicle handling skills
Car Road Design
Resulting Accident Toll
Perception skills
Perceived Level of Risk
14
Risk Homeostasis Theory

• Explains accident rate
• Closed Loop process between loss caution
• Motivate by accident counter measures to act more
  safely
• Reduce peoples willingness to take risks

Comparator
Perceived Costs and Benefits of Action
Alternatives
Target Level of Risk

-
15
Art of effective safety management is the art of
reducing the target level of risk
Target Level of Risk
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Opponents

• This theory is so bizarre...not a theory
• A more productive approach determine under
  which conditions behavior is altered to maintain
  level of risk
• As credible as the flat earth hypothesis
• ONeill, B Williams, A, (1998). Risk
  homeostasis hypothesis a rebuttal. Injury
  Prevention, 4, 92-93.
• All the data examined are found to be
  incompatible with the risk homeostasis theory
• Evans, L, (1996) Risk homeostasis theory and
  traffic accident data. Risk Analysis, 6,1,81-94.

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Uses

• Objective Personality Test
• Hergovich, A, et al. (2004). Zur dimensionalität
  und konstukvalidität eine videobasierten,
  objektiven persönlichkeitstests zur messung der
  risikobereitschaft im straßenverkehr (The
  construct validity of a video based, objective
  personality test as a measure of risk-taking in
  traffic) Zeitschrift für differentielle und
  diagnostische psychologie, 25, 2