Risk

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Risks Estimated to Increase Chance of Death by 0.000001 per Year (Wilson, 1979)

Activity                            Cause of death
--------                            --------------
Smoking 1.4 cigarettes              Cancer, heart disease
Drinking 1/2 liter of wine          Cirrhosis of the liver
Spending 1 hour in a coal mine      Black lung disease
Spending 3 hours in a coal mine     Accident
Living 2 days in New York or Boston Air pollution
Travelling 6 minutes by canoe       Accident
Travelling 10 miles by bicycle      Accident
Travelling 150 miles by car         Accident
Flying 1,000 miles by jet           Accident
Flying 6,000 miles by jet           Cancer caused by cosmic radiation

1996 figures from the National Safety Council

Regulation: The cost of a life year

INTERVENTION                     COST PER LIFE-YEAR

Mandatory seat-belt-use law                   $69
Influenza vaccination for all citizens       $140
Sickle-cell screening for black newborns     $240
Federal law requiring smoke detectors
 in homes                                    $920
Mandatory motorcycle-helmet laws           $2,000
Pneumonia vaccination for seniors          $2,200
Chlorination of drinking water             $3,100
Smoking-cessation advice for people who
 smoke more than one pack per day          $9,800
Alcohol-safety programs for drunk drivers $21,000
AZT for people with AIDS                  $26,000
Smoke detectors in airplane lavatories    $30,000
Child-resistant cigarette lighters        $42,000

More

Ban asbestos in pipeline wrap             $65,000
Child-restraint systems in cars           $73,000
Promote voluntary helmet
 use for all-terrain vehicles             $44,000
National 55 mph speed limit               $89,000
Community health-care services
  for women and infants                  $100,000
Widen lanes on rural roads
  from 9 to 11 feet                      $150,000
Pneumonia vaccination for
 children age 2Ä4                        $170,000
Redesign chain saws to reduce
  rotational kickback injuries           $230,000
Ban amitraz pesticide on pears           $350,000
Ozone-control program for
  southern coast of California           $610,000

More

Warning letters sent to
  problem drivers                        $720,000
Ejection system for the
  Air Force B-58 bomber                $1,200,000
Triple the wind-resistance
  capabilities of new buildings        $2,600,000
Seat belts for school-bus passengers   $2,800,000
Ban asbestos in packing                $5,700,000
Strengthen buildings in
  earthquake-prone areas              $18,000,000
From "Five-Hundred Life-Saving Interventions and Their Cost-Effectiveness," a study conducted by Tammy 0. Tengs, et al., and published in Risk Analysis, Vol. 15, No. 3.

Why? Factor analysis of risks (Slovic)

slovic graph

Intuitions about risk

Risk expenditures (McDaniels, 1988)

Mean WTP U.S. deaths Implied U.S. Actual or proposed
Hazard in survey per year national WTP expenditures
Workplace chemical $7.95 1 $715 mil. > $11 mil.
Explosives $7.68 2 $345 mil. $3 mil.
Aviation $46.07 40 $103 mil. $680,000
Power tools $15.05 80 $17 mil. $430,000
Automobiles $161.30 10,000 $1.3 mil. $95,000

Individual vs. statistical

"There is a distinction between an individual life and a statistical life. Let a 6-year-old girl with brown hair need thousands of dollars for an operation that will prolong her life until Christmas, and the post office will be swamped with nickels and dimes to save her. But let it be reported that without a sales tax the hospital facilities of Massachusetts will deteriorate and cause a barely perceptible increase in preventable deaths - not many will drop a tear or reach for their checkbooks." (Schelling, 1968)

Natural vs. unnatural (Kahneman and Ritov)

People willing to contribute $19 to an international fund to save Mediterranean Dolphins when the dolphins were ``threatened by pollution''

$6 when the dolphins were ``threatened by a new virus''

Zero risk (Baron, Gowda, and Kunreuther)

Two cities have landfills that affect the groundwater in the area. The larger city has 2,000,000 people, and the smaller city has 1,000,000. Leakage from the landfill in the larger city will cause 8 cases of cancer per year. Leakage from the landfill in the smaller city will cause 4 cases of cancer per year. Funds for cleanup are limited. The following options are available:

1. Partially clean up both landfills. The number of cancer cases would be reduced from 8 to 4 cases in the larger city and from 4 to 2 cases in the smaller city.

2 Totally clean up the landfill in the smaller city and partially clean up the landfill in the larger city. The number of cancer cases would be reduced from 8 to 7 cases in the larger city and from 4 to 0 cases in the smaller city.

3. Concentrate on the landfill in the larger city, but partially clean up the landfill in the smaller city. The number of cancer cases would be reduced to from 8 to 3 cases in the larger city and from 4 to 3 cases in the smaller city.

Precautionary principle

windmill

Individual risk and protective behavior

Viscusi et al.: smokers in Spain:

Worry has independent effects (Baron et al.)

Neglect of probability

Seat-belt example

Rottenstreich and Hsee (2001):
$7 (median) to avoid a 1% chance of a shock
$10 to avoid a 99% chance

People don't ask for information

Neglect of probability: Gurmankin Levy and Baron (2005)

badness responses

Intuitive toxicology

35% of the public agreed that, ``For pesticides, it's not how much of the chemical you are exposed to that should worry you, but whether or not you are exposed to it at all.'' Only 4% of the scientists agreed. (Kraus et al.)

20% agreed that, ``If something can cause harm to the body in large amounts, then it is always better not to eat it even in small amounts'' (Rozin et al., 1996).

26% agreed that a diet free of salt is healthier than the same diet with a pinch of salt.

Omission bias and neglect of numbers

A site that opposes vaccination

Emotion and financial risk

investment cycles

Investment risk

People think too short:
* Won't pay x for (3.5x,.33), but they will if they decide on a group of 3 (Gneezy and Potters, 1997).

But they are overconfident starting new businesses (Camerer and Lovallo, 1999):
* Competitive game, chance or skill (puzzles).
* Made more money when chance.
* More confident when skill.

Insurance: Normative theory

Redistribution: declining marginal utility

Insurance: biases

low deductables (and then don't file claims): e.g., people pay $100 to reduce deductable from $1000 to $500, with 5% claim rate (Snydor, 2006)

failure to use subsidy (flood): possibly the result of reducing low probabilities to zero

ambiguity

Vividness (Johnson et al., 1993):
$14.12 for insurance against death from ``any act of terrorism,''
$10.31 for death from ``any non-terrorism related mechanical failure,''
$12.03 for death from ``any reason.''

Loved possessions (Hsee and Kunreuther)

Suppose that you are visiting Europe now and bought two vases there for $200 each. ... Suppose that the two vases will be packed in the same box so that if one vase is damaged, the other is also damaged...

The shipping company offers insurance for individual items. If you buy insurance for a given vase and if it is damaged in shipment, then you will receive a check of $200 as compensation.

Of the two vases, you love one much more than the other. You feel that the vase you love is worth $800 to you and the other one is worth only $200 to you.

Suppose that the insurance premium for the vase you love is $12, and the insurance premium for the vase you don't love as much is $10. Suppose also that you have enough money to insure only one vase. If you are to insure one, which one will you insure?

Tort law

tort law

Biases in tort law

retribution, not deterrence

confusion of compensation and deterrent functions

"Standard view" of global warming (Baron, 2006)

People caused it.

Recently we knew were doing it.

It will cause harm, particularly in some poor countries.

It could be even worse.

We need to reduce it.

The polluters should pay, and the rich nations.

Alternative view (Schelling, Copenhagen Consensus)

Attempt to undo it is too little, too late.

Not cost-effective compared to other things like helping poor countries directly.

(The state of poor countris also has risks.)

What if this alternative view is true? Why might people reject it?

Some recent recognition (NYT 4/11/07)

lowland in India map of delta region

Biases: Naturalism (Nature is good)

It matters if people cause it.

Subjects in one study were willing to contribute about $19 to an international fund to save Mediterranean dolphins when the dolphins were "threatened by pollution" but only $6 when the dolphins were "threatened by a new virus." (Kahneman et al., 1993; Kahneman and Ritov, 1994).

In another study, subjects thought that compensation for injuries such as infertility should be greater when the injury is caused by a drug rather a natural disease, even if the penalty paid by the drug maker does not affect the amount of compensation paid to the victim (Baron and Ritov, 1993).

Polluter pays

Subjects preferred to have companies clean up their own hazardous waste, even if the waste threatened no one, rather than spend the same amount of money cleaning up the much more dangerous waste of a defunct company (Baron, Gowda, and Kunreuther, 1993).

Undoing

Beattie and Baron (1995) found that people prefer in-kind penalties over out-of-kind penalties.

For example, if a company caused a fire that destroyed a forest (beach), subjects would rather have the company pay for the planting of a new forest (preservation of a beach) than for preservation of a beach (planting of a new forest). The forest was to be planted anyway.

Parochialism

Own-group bias.

Self-interest illusion: "I am a member of my group. So anything that helps my group helps me. Thus, if I sacrifice for my group, I help myself."

Would cause oppoisition to alternative ways of helping.

Availability cascades (Kuran and Sunstein, 1999)

Global warming may be more "available" than some of the alternative problems, such as overfishing or flu.

Concerns for risk risk and fall in cycles that sometimes have little to do with evidence (Loewenstein \& Mather, 1990).

Experiment: polluter-pays, undoing, parochialism

Done on the web; 76 Ss; age 22--74 (median 42.5); 26\% male. (Five goofs.)

28 items in random order: 14 about mitigation, 14 prevention. (Did not differ.)

Scenarios in which rich nations could make a sacrifice --- a payment --- in their current economic well-being in order to counteract the future harms of global warming.

Varied the cause of the warming: natural; rich nations; or poor nations.

Varied the nations affected: rich or poor.

Payment could either be made by the affected country or by another country.

Typical item

Suppose that warming is caused by human activity in some rich countries including your own. And the effect is felt by other rich countries not including your own, where it would cause a 10\% decline in the economy in 50 years.

Suppose further that your country and the other rich countries could largely prevent this decline by taking steps to reduce global warming (such as reducing emissions), but such actions would require paying a price now in terms of their own economies. This is the only way to help those affected.

Typical item, continued

What is the most that the rich countries should be willing to pay now, as a reduction in their economies, in order to reduce in 50 years the 10% economic decline caused by global warming to a 2% decline in other rich countries not including your own. (Suppose that you were voting, and if a majority gave an answer at the actual cost or higher, then the actual cost would be paid.)
None; should not pay at all. 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% 12% 14% or more

[same scale used after each question]

Typical item, continued

Now suppose that the rich countries had another option. They could provide general economic assistance now in a way that does not reduce global warming and does not mitigate its direct effects. This assistance would reduce the 50-year 10% economic decline to only 1% for the same cost as the first option. The rich countries must choose one option only. If they vote for both, then the one with the highest average value to the voters will take effect.

What is the most that the rich countries should be willing to pay now in order to prevent this decline by taking steps to reduce global warming (such as reducing emissions) (the original option, which would reduce the 10% economic decline to 2%)?

What is the most that the rich countries should be willing to pay now in order to provide general economic assistance (reducing the 10% economic decline to 1%)?

Items (14 mitigation, 14 prevention)

Causes
nature
poor countries
rich countries including your own
rich countries not including your own
Victims
some poor countries
other poor countries
the same poor countries
some rich countries including your own
some rich countries not including your own
other rich countries not including your own
the same rich countries
other rich countries including your own

Design

Half of the cases involved mitigation and half involved prevention, for the first two questions on each screen.

The third question concerned alternative, more efficient, ways of helping. The contrast between the first question and the third thus tested the strength of the desire to undo, rather than help in some other way.

Within each group of 14 questions, the experiment varied:

Some combinations of variables made no sense, so the data were analyzed using within-S multiple regression.

Conclusions

People seem to favor undoing the effects of global warming, rather than providing other, more efficient, economic assistance.

People also tend to be parochial, more concerned with their own co-nationals than with others.

They are also willing to pay to reduce harm that "they," in some general sense, have inflicted. The "they" extends to residents of other rich nations but not, in this study, to humans on the whole, as opposed to nature.

Same biases may matter if Schelling is wrong

Kyoto opponents make their case based on "scienfitif uncertainty" about whether humans caused warming.

(Arugably, the economic uncertainty is much bigger.)

Responsibility leads to opposition to efficient solutions such as emissions trading.

Parochialism may lead to opposition to treaties once it is recognized that the beneficiaries are foreigners.

General policy recommendations

Smart government, trust (Breyer, Sunstein)

Libertarian paternalism (Sunstein and Thaler)

Education

Information

"He who refuses to do arithmetic is doomed to talk nonsense." John McCarthy