This page includes my comments on risk theory and links to other sites.
My writings are in black. Plagiarized text is in maroon, sometimes highlighted by me in red.
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Behavioral research on drivers and driving
DrDriving's Bibliography of Aggressive Driving Part 4: http://www.aloha.net/~dyc/references4.html Very extensive bibliography -- some with hyperlinks.
See also Nuclear Green. Why we need to counter irrational opposition to nuclear power.
Activities that increase chance of premature death by 1 in a million. Examples: live 2 months in stone or brick building (cancer from high average radiation), and live 5 years at boundary of US nuclear power plant (cancer from radiation).
number of days lost per lifetime (on average), due to various causes. Examples: having an accident (safe job) -- 30 days; natural radiation -- 11; nuclear reactor accident (antinuclear group) -- 2; nuclear react accident (pronuclear estimate) -- 0.02; home smoke alarm -- - 10 (minus 10).
Achieving Public Understanding and Acceptance of Nuclear Power: http://www2s.biglobe.ne.jp/~INSC/INSCAP/Pubund.html International Nuclear Societies Council. . . .
The research shows that risks from familiar things, which people feel they understand, control and make decisions about themselves, and from which they believe they derive a direct benefit, are perceived by the general public to be relatively low. This is so even when there is common knowledge that the technology or activity results in a large number of deaths, as for example in automobile accidents. The public apparently concludes that automobiles, even though they harm many more people than nuclear power reactors, are much less risky because they do not meet the above criteria. The construction and operation of nuclear power plants and radioactive waste management facilities, on the other hand, meet most of these criteria, and it has been suggested that this is one of the root causes of the public fear that surrounds nuclear power. . . .
Re Coal vs. Nuclear: http://www.vanderbilt.edu/radsafe/9512/msg00061.html . . . Mr. Vitalis apparently has concluded that the nuclear option is 'orders of magnitude' less risky than the coal option from his examination of the data, and perhaps this is indeed the case, even when the psychological aspects are factored in. However, while we can do all the risk analyses we wish, and indeed as health physicists we should continue to do this type of activity, we also need to keep in mind that if the American public does not favor the nuclear option, this is their privilege in our relatively free and democratic society, no matter what conclusions we scientists come to regarding risks. . . . Part of a thread, including the following: . . .
. . . Coal vs. Nuclear: http://www.vanderbilt.edu/radsafe/9512/msg00051.html . . . Just because the answer comes up that nuclear power (including the ultimate disposal of the wastes and the potentials for accidents are factored in) is orders of magnitude less risky than mining and burning coal doesn't make it a biased study. When you say 'we will not try to justify nuclear power', it sounds like nuke plants are some kind of terrible mistake that the nuclear industry is trying make look benevolent. Nuclear power needs no more justification. The only thing wrong with it is that it's costly and the only reason its costly is that people somehow believe that radiation risk is far worse than any other kind. . . .
Eureka County Nuclear Waste Page: http://www.yuccamountain.org/faq.htm
What is the role of perceived risk?
The New Mexico Supreme Court case in August 1992 held that governments must pay damages for loss of a person's property value if fear (regardless of whether it is well-founded) of nuclear waste transportation affects the property's market value.
In the case, justices said the city of Santa Fe must compensate a couple $337,815 in loss of value to property they own near a bypass the city planned to build to be used to transport nuclear waste to the Waste Isolation Pilot Project (WIPP) near Carlsbad. . . .
What are other countries doing about their nuclear waste from power plants?
Canada generates about 15% of it electricity from nuclear power. The 19 reactors are owned and operated by the provincial government utilities which have the primary responsibility for the management of the wastes, which are stored at the reactors. The federal government is funding the development of technology for the permanent disposal of nuclear fuel at the Underground Research Laboratory in Manitoba. Upon completion scientists there should have a better understanding of the behavior of waste packages stored in a granite rock repository.
Currently, an independent commission is conducting a four year study of the government's plan to bury the waste in granite. A unique feature of Canada's program is the government's pledge that the research facility will not become the repository, and that the provinces producing the waste must dispose of it. . . .
NUCLEAR ENERGY A WITCH TRIAL - In defense of nuclear energy: http://mnsgi.ulb.ac.be/pub/pel/devooght_bns/WITCH_part14.htm 14. IN DEFENSE OF NUCLEAR ENERGY
Let us summarize our findings.
Given the foreseeable cost of renewable energies, nuclear power is the only alternative for a sizeable share of this carbon free power.
Nuclear energy is fully compatible with a sustainable world’s development, much more than fossil fuel energies and at least as well as renewable energies.
External costs for nuclear energy are much smaller than for all fossil fuels with nuclear < gas < oil < coal.
External cost for wind alone is greater than for nuclear.
To use external cost for wind alone is incorrect if market penetration is not marginal since backup should be considered; even with gas backup the total external cost becomes comparable to gas and significantly higher than for nuclear.
Internal and external costs of photovoltaics exclude its consideration for large scale production in North-Western Europe.
Nuclear phaseout is an economic nonsense and an ecological crime.
Contrary to fossil fuel energies, all costs of nuclear fuel cycle are taken into account.
Pricing electricity at its true total cost, for all generating options, will leave nuclear power as the best option for base load electricity production.
I started this talk with the statement that nuclear energy was the subject of a witch trial. I cannot do better to illustrate this fact than to quote from the book «Higher Superstition» of P. Gross and N. Levitt [36] : «...in any discussion of the greenhouse effect, alternatives to CO2 emitting energy technologies such as nuclear power or hydroelectric projects are immediately ruled out of court because they have been assigned a place by the environmental left in its fixed demonology. Unchanging casts of devils completely exclude the careful, unemotional weighting of costs and benefits, of relative risks and relative certainties that is a necessary part of making pragmatic judgments. This is wrily illustrated by the fact that radical advocacy of «solar» power never puts hydroelectricity into that category... To a true believer however, it is far easier to abandon a saint than a demon, and hydroelectric power is rife with demons.»
See also the prececing chapter (13) of this document for comments on unreasonable costs imposed on nuclear power per death avoided, as follows:
NUCLEAR ENERGY A WITCH TRIAL - The regulatory ratchet.
Nuclear Energy Institute: http://www.nei.org/doc.asp?catnum=3&catid=493 Statement of Corbin A. McNeill, Jr., Chairman, President and Chief Executive Officer, PECO Energy Company, National Energy Policy: The Future of Nuclear Energy Before the Committee on Commerce Subcommittee on Energy and Power U.S. House of Representatives, Washington, DC, June 8, 2000. . . .
Current Federal Policy
The Federal government's existing policy toward nuclear energy can best be described as one of neglect, bordering at times on open hostility. . . .
* With few exceptions, Federal policy makers completely disregard the role of nuclear energy in meeting the nation's energy needs. It is a constant source of amazement and frustration to read or listen to speeches by the nation's leading energy policy makers -- both within the Administration and within Congress -- which address energy and electricity policy without once mentioning the word "nuclear." As recently as May 24, . . . the Department of Energy's written statement, which was 20 pages long, mentioned nuclear energy only once, and then only as part of a laundry list . . .
* In nuclear power, we have a mature baseload technology that generates billions of kilowatts of electricity annually without emitting any of the pollutants associated with acid rain, smog, haze, ozone, or global climate change. Yet, nuclear power is rarely credited with its role in emissions avoidance or cited as a source of future avoided emissions. To put the role of nuclear power in perspective, if the U.S. closed all 103 nuclear plants and replaced them with fossil fired plants, we would have to remove 90 million cars from America's highways just to maintain the air quality at its current level. . . .
* . . . In fiscal year 1998, not a single Federal dollar was spent on research and development for an energy source that provides over 20 percent of the electricity generated in the U.S. . . .
* The nation's management program for used nuclear fuel is at least 12 years behind schedule. The Federal government's failure to meet its contractual and statutory deadline to begin accepting used fuel by 1998 threatens the continued operation of some of the nation's best run nuclear power plants. The Clinton Administration has failed to offer a concrete plan for addressing the crisis faced by these plants, while Congress has failed to reform a flawed funding process . . . President Clinton's veto of recently-passed used fuel legislation ignored what has traditionally been broad, bipartisan support . . .
Given these facts, it is hard to argue that Federal policy toward nuclear energy can be characterized as anything but neglectful at best. . . .
Continued Operation of Existing Plants
Contrary to conventional wisdom just a few years ago, the future for the existing fleet of nuclear reactors in the United States is bright. . . .
the Federal government must treat nuclear power like any other electric generating technology and should not make arbitrary distinctions that disadvantage nuclear energy (this includes the recognition in Federal environmental policies the non-emitting benefits of nuclear energy) . . .
The federal government can and should play an important role in educating the public about the very low and manageable risks related to commercial nuclear power as compared other endeavors in society. . . .
Radiation Resources: http://newnet.lanl.gov/radresource.asp Los Alamos National Laboratory Newnet Neighborhood Environmental Watch Network. Radiation Resources. Excellent links!
RADIATION RISKS AND LINEARITY SOUND SCIENCE?: http://www.gr.is/nsfs/mossman.htm Kenneth L. Mossman, Arizona State University, Tempe, Arizona.
Abstract-Significant questions have been raised about the appropriateness of the linear, no-threshold (LNT) theory as a predictive model to estimate health effects at low radiation doses and as a theoretical foundation for radiation protection standards and practices. The LNT model is based on three fundamental assumptions: ( 1 ) adverse health outcomes (e.g., cancer) might result from a single ionizing event in a critical cell, i.e., any radiation dose, no matter how small, is potentially harmful, (2) the probability of adverse health outcomes is linearly related to absorbed dose, and (3) radiation damage is not repairable. It is now well-known that the dose-response curves for some, but not all, health effects are non-linear in the low dose range, that radiation-induced damage (to DNA) can be repaired, and that cellular DNA is in a dynamic state in which damage, due to metabolic processes, is constantly occurring and being repaired. This paper explores some of the scientific issues at the heart of the LNT debate including limits of radioepidemiology studies, repair of radiation injury , and hormesis. It is concluded that the validity of the LNT model must be seriously questioned and that alternative approaches to regulatory decision making must be identified.
First, regulatory compliance costs too much. . . . there is little epidemiological evidence to show that reducing exposure to environmental carcinogens leads to a reduction in cancer risk. In a comprehensive analysis of the costs and benefits of federal social regulation, Hahn and Hird ( 1991 ) found that regulations aimed at reducing occupational safety and health risks have imposed costs of about $9 billion annually for negligible risk reduction benefits (Table 1 ). Nuclear power regulations are also very costly. Although it has not been possible to estimate benefits of nuclear power regulations directly, such benefits are not likely to be much greater than those for occupational health and safety (Table 1). . . .
Table 1. Costs and benefits of regulation . . . Table 2. Lowest Doses of Low Let Radiation Associated with Cancer . . . Table 3. Extrapolating Health Risks . . . Table 4. Intrinsic DNA Damage . . .
In the past, the LNT model provided a reasonable, conservative approach to risk assessment for the purposes of standard setting and radiation protection practices. The assumptions underlying the model were consistent with the scientific knowledge of the time. Substantial new information about human cancer, carcinogenesis, molecular biology of cancer, and human radiobiology at low doses now call into question the validity of the LNT model assumptions. Although much is yet to be learned about cancer at low doses of radiation, sufficient information is available now to apply less conservative predictive models with reasonable assurance that public health will not be compromised.
A socio-psychological model for analyzing risk communication processes: http://www.massey.ac.nz/~trauma/issues/2000-2/rohrmann.htm The Australasian Journal of Disaster and Trauma Studies ISSN: 1174-4707 Volume : 2000-2. A/Prof Bernd Rohrmann, Dept. of Psychology, Univ. of Melbourne, Parkville, Victoria, Australia. In this conceptual article, a theoretical framework for the socio-psychological process underlying risk information, communication and education efforts is outlined. The model identifies a set of message features (e.g., content clarity and acceptance), person characteristics (e.g., prior experience, cognitive biases, attitudes), social influences (e.g. , peers, media) and context factors (e.g., societal safety culture) which determine whether, and if so, how a particular risk communication regarding a hazard (i.e., a health & safety threat) influences individual risk assessment and management (i.e., risk appraisal, decision for preventive action and actual risk behavior and disaster preparedness). Three overlapping processes need to be considered and linked: how people deal with hazards, how risk information is processed and evaluated, and how accepted information affects risk perception, evaluation and behavior. As interactive risk communication is far more likely to be effective, two-way communication pathways are looked at as well. . . .
Perrow, C. Normal Accidents Living with High Risk Technologies: .http://pup.princeton.edu/titles/6596.html Normal Accidents Living with High Risk Technologies Charles Perrow Paper | 1999 | $22.50 / £15.95 386 pp. | 6 x 9.
Normal Accidents analyzes the social side of technological risk. Charles Perrow argues that the conventional engineering approach to ensuring safety -- building in more warnings and safeguards -- fails because systems complexity makes failures inevitable. He asserts that typical precautions, by adding to complexity, may help create new categories of accidents. (At Chernobyl, tests of a new safety system helped produce the meltdown and subsequent fire.) By recognizing two dimensions of risk -- complex versus linear interactions, and tight versus loose coupling -- this book provides a powerful framework for analyzing risks and the organizations that insist we run them.
The first edition fulfilled one reviewer's prediction that it "may mark the beginning of accident research." In the new afterword to this edition Perrow reviews the extensive work on the major accidents of the last fifteen years, including Bhopal, Chernobyl, and the Challenger disaster. The new postscript probes what the author considers to be the "quintessential 'Normal Accident'" of our time: the Y2K computer problem.
Charles Perrow is Professor of Sociology at Yale University. His other books include The Radical Attack on Business, Organizational Analysis: A Sociological View, Complex Organizations: A Critical Essay, and The AIDS Disaster: The Failure of Organizations in New York and the Nation.
"[Normal Accidents is] a penetrating study of catastrophes and near catastrophes in several high-risk industries. Mr. Perrow ... writes lucidly and makes it clear that `normal' accidents are the inevitable consequences of the way we launch industrial ventures.... An outstanding analysis of organizational complexity." -- John Pfeiffer, The New York Times. . . .
Normal Accidents by Charles Perrow: http://oak.cats.ohiou.edu/~piccard/entropy/perrow.html Book Review Normal Accidents by Charles Perrow.
Perrow investigates normal accidents in high-risk systems. He uses these and a number of other words in a technical sense . . . High-Risk, Normal Accidents, Discrete Failures, Redundant Sub-systems, Interactive Complexity, Tight Coupling, Incomprehensibility, Operator Error, For want of a nail ..., Transformation, Organizations. . . .
OCF Paper: http://www.wvi.com/~vic/wou/Ed%20Psych%20512/OCF%20Paper/OCFFinalDraft.htm Open Canopy Fatalities and Risk Homeostasis: A Correlation Study. By: Vic Napier, Under Direction of: M. Wangeci Gatimu, Western Oregon University.
. . . technical improvements in sport skydiving have resulted in a dramatic decrease in skydiving fatalities related failure to activate a parachute. During the same time, there has been a dramatic increase in the number fatalities related to landing. Total annual fatalities have remained about the same during this period.
Although a connection between these trends has been suspected for some time, a relationship between the two trends has never been the topic of academic research. . . .
This paper will establish that a relationship exists between the increase in Open Canopy Fatalities and decrease in No Pull/Low Pull fatalities that is explainable by risk homeostasis theory.
See also Nuclear power.
Culture of Fear Why Americans Are Afraid of the Wrong Things: http://hallentertainment.com/pop_culture/19.shtml Book by Barry Glassner, Ph.D.. 'Excellent': reviews.
Skeptics Society--Book Reviews: http://www.skeptic.com/review01.html The Fearful Angels of Our Nature. Michael Shermer. A review of The Culture of Fear: Why Americans Are Afraid of the Wrong Things, by Barry Glassner. New York: Basic Books.
. . . Religions play on our fears by hyping up the doom and gloom of this world to make the next world seem all the more appealing. On May 17, 1999, an evangelical Christian friend of mine insisted that we are in the “end times” because the Bible prophesied an increase in immorality and malfeasance. Since everyone knows crime is an epidemic problem in America that worsens by the year (“just look at the recent Colorado shooting,” he enthused), the end is nigh. I remember the date because it was the same day the FBI released its findings that we are in the midst of the longest decline in crime rates since the bureau began collecting data in 1930.
In other words, says Glassner, we are confronted with the paradox of being more fearful than we have ever been at the same time that things have never been so good. . . .
“million to one odds happen eight times a day in New York.” In America, million to one odds happen 266 times a day, and of those the most sensational dozen make the evening news, especially if captured on video. . . .
Not surprising, drug use, the lowest ranking risk factor associated with serious illness and death, received as much attention as the second-ranked risk factor, poor diet and lack of exercise. From 1990 to 1998, America’s murder rate decreased by 20 percent while the number of murder stories on network newscasts increased by an incredible 600 percent (and this doesn’t count O.J. stories) . . . .
NUCLEAR ENERGY A WITCH TRIAL - The regulatory ratchet: http://mnsgi.ulb.ac.be/pub/pel/devooght_bns/WITCH_part13.htm 13. THE REGULATORY RATCHET AND THE COST OF DEATH AVOIDED.
Most of the opposition of the public to nuclear energy may in general be traced to three factors:
-- a perception of risk at variance with the reality of the risk,
-- a disregard for comparisons with alternative solutions,
-- an omission of the fact that all human activities have costs associated to benefits.
This is the source of regulatory and legislative measures that lead to outright waste of money. . . .
to avoid one death, we should of course choose the cheapest, because money saved can be used to save a life in another field. The cost to avoid one death must be compared to the value of life: roughly speaking we should act every time the cost is smaller than the value currently given by society to one life. But if we compare different regulations, for instance the US Federal limits on public radiation exposure (table 13.1) we observe . . . that they are completely inconsistent: the estimated lifetime risk varies from 1/40 to1/36000. Exposure limits are much more severe for radiation than for fossil fuel pollutants for instance, but even within the radiation exposure rules, we have widely ranging limits. Obviously the geological containment limit is much too stringent.
TABLE 13.1: DIFFERENT FEDERAL LIMITS ON PUBLIC RADIATION EXPOSURE
Nuclear industry is, all over the world, the prey of regulatory ratcheting: norms are always being strenghtened, in a way out of proportion with norms in other industries. Some people argue that nuclear industry being a «new» industry, it should be an example. But this is plainly absurd because if we allocate a finite budget among different options the strenghtening of radiation norms at a cost greater than the value of life does not save additional lives but on the contrary is responsible for additional deaths. . . .
unreasonable norms burden the cost of nuclear power, erodes its competitiveness (but maybe is it the true motive?) and therefore favors fossil fuel energies, with the result that deaths and morbidities are indeed increased. . . .
See also the subsequent chapter (14) of this document for arguments in favor of nuclear power, as follows:
NUCLEAR ENERGY A WITCH TRIAL - In defense of nuclear energy.
Stephen Moore on flying-terrorism on National Review : http://www.nationalreview.com/balance/balance091701.shtml Don’t Fear Flying. Flying is a lot safer than most Americans think. Mr. Moore is president of the Club for Growth. Sep 17, 2001.
. . . Even accounting for the four hijackings last week, . . . airplane travel is now the safest form of transportation ever devised. In 1998, for example, there were 14 million commercial airline flights carrying 615 million passengers. There were zero crashes and zero fatalities. In 1999 and 2000 there were less than five in each year. According to the research organization STATS, "your odds of dying in a plane crash [based on recent experience from the 1990s] and based on flying 100,000 miles a year on large commercial jets, are about 1 in 500,000." STATS also finds that if you fly just 2,000 miles a year, your odds of dying in a plane crash are roughly equivalent to your odds of being hit on the head by a plane falling on you.
I have talked to many people in recent days, including my wife, who say that they will from now on drive or take the train, whenever they have those options, rather than fly. This is the height of irrationality. The death rate from flying on commercial airlines is at least four times lower per mile traveled than driving a car. Train crashes are far more common than airplane crashes. In other words, if you are you are motivated by fear to drive to your out-of-town destination, your chances of dying are much, much higher than if you fly. . . .
Risk: http://www.enviroliteracy.org/risk.html . . . Environmental Literacy Council. Studies show, though, that public perceptions of risks rarely reflect the actually likelihood of the potential harm. . . . FURTHER READING "Perception of Risk" In this now-classic 1987 Science article, Paul Slovik finds that the public generally rates as more risky those things over which they have no control (nuclear power) than over behaviors which are actually more likely to result in harm but are voluntarily undertaken.
Risk Books Risks in Everyday Life: http://www.riskworld.com/BOOKS/topics/everyday.htm
Risk Homeostasis Theory by Wilde
See also Professor Wilde (Queen's U.) and Literature Review.
Risk HomeostasisOverview: http://www.wvi.com/~vic/wou/Ed%20Psych%20512/OCF%20Paper/References/RiskHomeostasisOverview.htm . . . presentation by Dr. Gerald Wilde to the Wilderness Risk Manager's Conference (Snowbird, Salt Lake City, Utah, Oct. 12-14), organized by NOLS (National Outdoor Leadership School) in Wyoming condenses Dr. Wilde's theories. I believe these theories could form the foundation of future safety initiatives in kayaking and canoeing and lead to greater enjoytment and safety in paddlesports. . . .
Introduction
Two safety policies that may well be pursued by the same accident prevention agency are the following. The first aims to reduce the severity of the consequences risky behaviour and takes the form of seatbelt installation . . . The second policy is to increase the severity the consequences of imprudent behaviour, and includes things such as speed bumps . . .
Apart from noting that these two policies seem logically contradictory, we will see that neither is likely to reduce the accident rate per head of population, because people adapt their behaviour to changes in environmental conditions. We will present theory and data to indicate that the loss in per capita safety and lifestyle-dependent health is unlikely to diminish, unless the amount of risk people are willing to take is reduced.
The choice of denominator in the calculation of accident rates
In any discussion about accident prevention the criterion of success should be clearly specified. What is is that we want to achieve, fewer accidents per unit distance driven, per hour of exposure to traffic, or per head of population per year . . .
The effect of the business cycle on accident frequency.
In the absence of a clear downward trend, traffic accident rates per capita show major fluctuations from one time period to another, and . . . these fluctuations go hand in hand with the business cycle . . .
The accepted level of accident risk
. . . other factors that influence the level of accepted risk; these are of a cultural, social or psychological kind. In general, the amount of risk that people are willing (in fact, prefer) to take can be said to depend on four utility factors: it will be greater to the extent that Factors 1 and 4 are higher, and Factors 2 and 3 are lower:
1. The expected benefits of risky behaviour alternatives (examples: gaining time by speeding, . . .
2. The expected costs of risky behaviour alternatives (examples: automobile repair expenses, . . .
3. The expected benefits of safe behaviour alternatives (examples: insurance discounts for accident-free periods, . . .
4. The expected costs of safe behaviour alternatives (examples: using an uncomfortable seatbelt . . .
The level of accident risk at which the net benefit is expected to maximize is called the target level of risk in recognition of the realization that people do not try to minimize risk (which would be zero at zero mobility), but instead attempt to optimize it. Risk homeostasis theory posits that people . . . compare the amount of risk they perceive with their target level of risk and will adjust their behaviour to attempt to eliminate any discrepancies between the two.
. . . This homeostatic mechanism . . . constitutes a case of circular causality: a change in the degree of caution displayed in behaviour brings about a change in the accident rate, while the accident rate also leads to a change in behaviour. The mechanism is similar to a thermostat . . . Similarly, the target level of risk is seen as the controlling variable in the causation dynamic of the per capita accident rate and it follows that the art of accident prevention is the art of reducing the level of risk that people are willing to accept. Becasue of the closed-loop nature of the control process, all other variables, such as variations in skill or environmental conditions can only produce minor and/or short-term fluctuations, and these are often eliminated through anticipatory adaptation by road users ("feed-forward control").
Evidence of risk homeostasis
In the fall of 1967 Sweden changed over from left-hand to right-hand traffic. This was followed by a marked reduction in the number of traffic fatalities per capita. About a year and a half later, the accident rate had returned to the pre-change-over trend. . . . The level of perceived risk dropped and less often exceeded the target level of risk. Consequently, road users opted for less cautious behaviour alternatives and the accident rate rose again. . . .
Numerous other findings can be explained by means of risk homeostasis theory. In road sections where the accident rate per km driven is low, drivers move faster. Mandatory wearing of seatbelts reduces the likelihood of death or injury in case an accident happens, but does not reduce the death rate per capita. . . .
The introduction of child-proof medicine vials has failed to limit the number of accidental poisonings . . .
Incentives for safety
. . . incentive systems for accident-free operation have shown to be a very powerful method for the reduction of the accident rate per person. Incentives, defined as rewards contingent upon fulfilling a future condition) increase the perceived benefits of safe behaviour alternatives (utility Factor 3 above). . . .
Epilogue
The theory of risk homeostasis (also known as "risk compensation") was primarily developed and validated in the area of road traffic. We have seen, however, that some of the supporting data come from quite different behaviour domains including smoking and settling in flood-prone territories. . . . the mechanisms that are involved in risk homeostasis are probably universal. . . .
G. S. Wilde (1988). Risk Homeostasis Theory and Traffic Accidents: Propositions, Deductions, and Discussion of Dissension in Recent Reactions, Ergonomics, 31, 441-468.
nmc - driving safety - sorta: http://list.miata.net/miata/1998-05/2836.html Miata Mailing List: May 1998, Message #2836. > . . .
from Dr. Wilde's book: "one's increased belief in personal skills increases risk taking out of proportion to real risk."
. . . This quote seems somewhat out of context, at least as a statement of a general proposition. For example, Wilde points out that the most skilled drivers of all -- racing drivers -- have higher accident rates (on public roads) than less skilled drivers. He rejects, however, the explanation that this is due to overconfidence, prefering instead to attribute the result to differences in risk targets: "In our view, the increased accident frequency of the racing drivers is not due to their superior driving skill -- since accident frequency in RHT [Risk Homeostasis Theory] is regarded as ultimately independent of skill -- but can more likely be attributed to a greater-than-average acceptance of risk, which induced them to pick up the activity of car racing to begin with. At their level of skill, driving like the average driver may be intolerably boring."
This is precisely what I suspect to be true of skilled paddlers. To the extent that they have higher accident rates, it may reflect different attitudes toward the optimal level of risk (as opposed to overconfidence). Elsewhere in the book Wilde provides yet another possible explanation. He suggests that those with fewer skills may tend to OVERestimate risk, which implies that they have lower accident rates than they would if their risk estimates were unbiased. As they become more skilled and better informed about an activity, their accident rates will tend to rise. Such individuals increase their exposure disproportionately with their improvement in skills. The resulting increase in accident rates is **desirable**, however, in the sense that such individuals are converging on their target levels of risk. Finally, if you are to be consistent in your application of Wilde's analysis, you should acknowledge that all of your talk of grave dangers awaiting ill-informed paddlers may contribute to the problem. Warnings can be counterproductive if they exaggerate the risk. As Wilde explains: "This is why over-use of warnings may be dangerous. A warning that is not perceived as needed will not be heeded -- even when it is needed. .. Similarly, 'a warning can increase danger when it overstates danger', meaning that a person's behaviour may become less cautious if that person has learned that the danger is usually less great than stated in the warning." The bottom line is that warnings are useful and productive only to the extent that the danger is not overstated. This is something that we should all keep in mind. Dan Hagen Bellingham, Washington . . .
Gerald J. S. Wilde: http://pavlov.psyc.queensu.ca/faculty/wilde/wilde.html Gerald J. S. Wilde Professor of Psychology Department of Psychology, Queen's University at Kingston, Kingston, Ontario. . . .
Ph.D. Faculty of Mathematics
& Physical Sciences, University of Amsterdam, 1962.
M.A. Psychology, University of Amsterdam, 1959.
B.A. Psychology, University of Amsterdam, 1955. . . .
Sleep Centre Projects: http://www.unisa.edu.au/sleep/projects/project_risk.html Young Men in a Hurry. Young people are over-represented in Australian road accident statistics. It has been suggested that this over-representation is due to a lack of driving skill. As a result, some accident countermeasures targeted at young drivers are based on making them more skilful. Such targeted accident countermeasures have been largely unsuccessful, which is difficult to account for if it is assumed that more skilful drivers are safer drivers. Wilde (1982) provides an explanation for this phenomenon with risk homeostasis theory (RHT). According to Wilde, raising the level of driving skill will have no effect on the accident rate because drivers have a target level of accident risk (usually greater than zero) where the net benefit of various driving behaviours are maximised. Wilde argues that in order to reduce the accident rate of young drivers, it is necessary to introduce countermeasures that reduce target levels of risk rather than increase skill levels. One factor that may influence accident risk is licensing method. In South Australia, young people may obtain a driver's licence by completing one of two methods: (a) competency-based training, or (b) a practical examination. It has been suggested that these two methods produce drivers with different attitudes and behaviours. . . .
Target Risk book: http://psyc.queensu.ca/target/ Target Risk. Dealing with the danger of death, disease and damage in everyday decisions. by Gerald J.S. Wilde (http://pavlov.psyc.queensu.ca/faculty/wilde/wilde.html ) HARDCOPY AVAILABLE FROM PDE Publications, 1994 . . .
Volume3, Number1: http://www.ualberta.ca/~envrisk/news.dir/vol3no1.html Eco-Research Chair in Environmental Risk Management Newsletter. April 1996 Vol. 3, No. 1. Scroll down about 70% of the page for the following:
Wilde presents an intriguing perspective, which he calls "risk homeostasis theory" as a generalized explanation for how individuals deal with danger in their everyday decisions. The essence of Wilde's theory is that individuals manage their own risk by a feedback control loop which seeks to maintain the risk they perceive near a target risk level, . . .
Wilde presents strong arguments for the utility of his theory. These range from some striking anecdotal commentary to convincing interpretations of some major behavioural studies which have shown that individuals will engage in more dangerous behaviour when they perceive conditions to be safer. . . . controlled experiment with Munich taxi drivers found that drivers with antilock breaking systems (ABS) drove more aggresively than those without and that equipping taxis with ABS failed to reduce accidents. However, accident rates were reduced when drivers were made responsible for paying part of vehicle repair costs, a motivation for reducing their target risk.
Illustrations of risk homeostasis theory were most clearly demonstrated for driving behaviour and traffic safety, but analogies to other risks seem plausible, provided there is risk information feedback to the individual. Because risk homestasis theory raises questions about the utility of engineering measures to reduce risk, it has received considerable critical commentary, including one description of the theory as "Wilde's law of conservation of misery."
Wilde's conclusion that substantial and sustainable improvements in public safety can only be achieved if individuals collectively seek lower target risk levels has profound implications for risk managers and public health disciplines like health promotion. This entertaining book is essential reading for those disciplines.
Telematics - Report: 4. http://www.kfv.or.at/gadget/wp1/report.htm Research steps conducted in the work-packages and achieved results. Implementing various telematic in-vehicle safety devices (SDs) will influence the driving task which is composed of task components at three different hierarchical levels: strategic, tactical and control tasks. The task demands imposed on the driver are met by also three levels of driver control (behaviour): knowledge-based, rule-based and skill-based. They form the repertoire of driving skills which have to be adapted to the requirements of an implemented SD. A huge literature survey revealed that there is no sufficient empirical basis of evaluating the effects SDs might have on road safety in general and on driving behaviour in particular. . . .
4.1.3. How safe are safety devices?
What are we actually doing when driving? What human abilities are necessary to perform the task and which factors influence the behaviour? The four chapters of work-package 1 are outlining possible effects of introducing different types of SDs from a psychological point of view, as well as methodological requirements to enable the assessment of the safety potential of SDs . . .
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