Risk is a concept that denotes the precise probability of specific eventualities. Technically, the notion of risk is independent from the notion of value and, as such, eventualities may have both beneficial and adverse consequences. However in general usage the convention is to focus only on potential negative impact to some characteristic of value that may arise from a future event.
Scenario analysis matured during Cold War confrontations between major powers, notably the U.S. and the USSR. It became widespread in insurance circles in the 1970s when major oil tanker disasters forced a more comprehensive foresight. The scientific approach to risk entered finance in the 1980s when financial derivatives proliferated. It reached general professions in the 1990s when the power of personal computing allowed for widespread data collection and numbers crunching.
Governments are apparently only now learning to use sophisticated risk methods, most obviously to set standards for environmental regulation, e.g. "pathway analysis" as practiced by the United States Environmental Protection Agency.
Qualitatively, risk is proportional to both the expected losses which may be caused by an event and to the probability of this event. Greater loss and greater event likelihood result in a greater overall risk.
Frequently in the subject matter literature, risk is defined in pseudo-formal forms where the components of the definition are vague and ill-defined, for example, risk is considered as an indicator of threat, or depends on threats, vulnerability, impact and uncertainty.
In engineering, the definition risk often simply is:
Or in more general terms:
There are more sophisticated definitions, however. Measuring engineering risk is often difficult, especially in potentially dangerous industries such as nuclear energy. Often, the probability of a negative event is estimated by using the frequency of past similar events or by event-tree methods, but probabilities for rare failures may be difficult to estimate if an event tree cannot be formulated. Methods to calculate the cost of the loss of human life vary depending on the purpose of the calculation. Specific methods include what people are willing to pay to insure against death, and radiological release (e.g., GBq of radio-iodine). There are many formal methods used to assess or to "measure" risk, considered as one of the critical indicators important for human decision making.
Financial risk is often defined as the unexpected variability or volatility of returns and thus includes both potential worse-than-expected as well as better-than-expected returns. References to negative risk below should be read as applying to positive impacts or opportunity (e.g., for "loss" read "loss or gain") unless the context precludes.
In statistics, risk is often mapped to the probability of some event which is seen as undesirable. Usually, the probability of that event and some assessment of its expected harm must be combined into a believable scenario (an outcome), which combines the set of risk, regret and reward probabilities into an expected value for that outcome. (See also Expected utility.)
In information security , a risk is defined as a function of three variables:
If any of these variables approaches zero, the overall risk approaches zero.
The management of actuarial risk is called risk management.
... Uncertainty must be taken in a sense radically distinct from the familiar notion of Risk, from which it has never been properly separated. The term "risk," as loosely used in everyday speech and in economic discussion, really covers two things which, functionally at least, in their causal relations to the phenomena of economic organization, are categorically different. ... The essential fact is that "risk" means in some cases a quantity susceptible of measurement, while at other times it is something distinctly not of this character; and there are far-reaching and crucial differences in the bearings of the phenomenon depending on which of the two is really present and operating. ... It will appear that a measurable uncertainty, or "risk" proper, as we shall use the term, is so far different from an unmeasurable one that it is not in effect an uncertainty at all. We ... accordingly restrict the term "uncertainty" to cases of the non-quantitive type.
A solution to this ambiguity is proposed in "How to Measure Anything: Finding the Value of Intangibles in Business" by Doug Hubbard:
In this sense, Hubbard uses the terms so that one may have uncertainty without risk but not risk without uncertainty. We can be uncertain about the winner of a contest, but unless we have some personal stake in it, we have no risk. If we bet money on the outcome of the contest, then we have a risk. In both cases there are more than one outcome. The measure of uncertainty refers only to the probabilities assigned to outcomes, while the measure of risk requires both probabilities for outcomes and losses quantified for outcomes.
Risks in personal health may be reduced by primary prevention actions that decrease early causes of illness or by secondary prevention actions after a person has clearly measured clinical signs or symptoms recognized as risk factors. Tertiary prevention (medical) reduces the negative impact of an already established disease by restoring function and reducing disease-related complications. Ethical medical practice requires careful discussion of risk factors with individual patients to obtain informed consent for secondary and tertiary prevention efforts, whereas public health efforts in primary prevention require education of the entire population at risk. In each case, careful communication about risk factors, likely outcomes and certainty must distinguish between causal events that must be decreased and associated events that may be merely consequences rather than causes.
The central insight in the methodology for incorporating economic risks arise from the realization of the fact that however manifold and diverse might be the causes, or factors, of risks around a specific project or business (for instance, the hike in the price for raw materials, the lapsing of deadlines for construction of a new operating facility, disruptions in a production process, emergence of a serious competitor on the market, the loss of key personnel, the change of a political regime, natural contingencies, etc.), all of these are ultimately manifested under only two guises. According to CCF Conception the economic risk consists in that: "Actual positive conventional cash flows (income, inflows) turn out to be less than expected AND / OR Actual negative conventional cash flows (expenditures, outflows) turn out to be larger than expected (in absolute terms)".
Such lucid and unambiguous conceptual treatment of such a complex and multi-faceted notion as the economic risk emphasizes the very core of the question. The "economic risk is not an abstract ‘uncertainty’ or ‘possibility of failure’ or changeableness (variability) of the outcome… The economic risk – is a monetary amount which might be under-collected and/or over-paid." Just as in music, one must use musical notes and staves—not alphabet letters or colors—to render a melody, in describing economic risk, we must ultimately operate with monetary units and not with the percentages of discount rates, magnitudes of volatility or anything else. (See )
In the workplace, incidental and inherent risks exist. Incidental risks are those which occur naturally in the business but are not part of the core of the business. Inherent risks have a negative effect on the operating profit of the business.
Criticism has been leveled at the amoral ("rational") application of quantitative risk assessment.
The total risk is then the sum of the individual class-risks.
In the nuclear industry, consequence is often measured in terms of off-site radiological release, and this is often banded into five or six decade-wide bands.
The risks are evaluated using fault tree/event tree techniques (see safety engineering). Where these risks are low, they are normally considered to be "Broadly Acceptable". A higher level of risk (typically up to 10 to 100 times what is considered Broadly Acceptable) has to be justified against the costs of reducing it further and the possible benefits that make it tolerable—these risks are described as "Tolerable if ALARP". Risks beyond this level are classified as "Intolerable".
The level of risk deemed Broadly Acceptable has been considered by regulatory bodies in various countries—an early attempt by UK government regulator and academic F. R. Farmer used the example of hill-walking and similar activities which have definable risks that people appear to find acceptable. This resulted in the so-called Farmer Curve of acceptable probability of an event versus its consequence.
The technique as a whole is usually referred to as Probabilistic Risk Assessment (PRA) (or Probabilistic Safety Assessment, PSA). See WASH-1400 for an example of this approach.
In finance, risk has no one definition, but some theorists, notably Ron Dembo, have defined quite general methods to assess risk as an expected after-the-fact level of regret. Such methods have been uniquely successful in limiting interest rate risk in financial markets. Financial markets are considered to be a proving ground for general methods of risk assessment.
However, these methods are also hard to understand. The mathematical difficulties interfere with other social goods such as disclosure, valuation and transparency. In particular, it is often difficult to tell if such financial instruments are "hedging" (purchasing/selling a financial instrument specifically to reduce or cancel out the risk in another investment) or "gambling" (increasing measurable risk and exposing the investor to catastrophic loss in pursuit of very high windfalls that increase expected value).
As regret measures rarely reflect actual human risk-aversion, it is difficult to determine if the outcomes of such transactions will be satisfactory. Risk seeking describes an individual whose utility function's second derivative is positive. Such an individual would willingly (actually pay a premium to) assume all risk in the economy and is hence not likely to exist.
In financial markets, one may need to measure credit risk, information timing and source risk, probability model risk, and legal risk if there are regulatory or civil actions taken as a result of some "investor's regret".
"A fundamental idea in finance is the relationship between risk and return. The greater the amount of risk that an investor is willing to take on, the greater the potential return. The reason for this is that investors need to be compensated for taking on additional risk."
"For example, a US Treasury bond is considered to be one of the safest investments and, when compared to a corporate bond, provides a lower rate of return. The reason for this is that a corporation is much more likely to go bankrupt than the U.S. government. Because the risk of investing in a corporate bond is higher, investors are offered a higher rate of return."
Due to such cost and demand risks, cost-benefit analyses of public works projects have proved to be highly uncertain.
The main causes of cost and demand risks were found to be optimism bias and strategic misrepresentation. Measures identified to mitigate this type of risk are better governance through incentive alignment and the use of reference class forecasting.
Huge ethical and political issues arise when human beings themselves are seen or treated as 'risks', or when the risk decision making of people who use human services might have an impact on that service. The experience of many people who rely on human services for support is that 'risk' is often used as a reason to prevent them from gaining further independence or fully accessing the community, and that these services are often unnecessarily risk averse.
For instance, an extremely disturbing event (an attack by hijacking, or moral hazards) may be ignored in analysis despite the fact it has occurred and has a nonzero probability. Or, an event that everyone agrees is inevitable may be ruled out of analysis due to greed or an unwillingness to admit that it is believed to be inevitable. These human tendencies to error and wishful thinking often affect even the most rigorous applications of the scientific method and are a major concern of the philosophy of science.
All decision-making under uncertainty must consider cognitive bias, cultural bias, and notational bias: No group of people assessing risk is immune to "groupthink": acceptance of obviously wrong answers simply because it is socially painful to disagree, where there are conflicts of interest. One effective way to solve framing problems in risk assessment or measurement (although some argue that risk cannot be measured, only assessed) is to raise others' fears or personal ideals by way of completeness.
In The Gift of Fear, Gavin de Becker argues that "True fear is a gift. It is a survival signal that sounds only in the presence of danger. Yet unwarranted fear has assumed a power over us that it holds over no other creature on Earth. It need not be this way."
Risk could be said to be the way we collectively measure and share this "true fear"—a fusion of rational doubt, irrational fear, and a set of unquantified biases from our own experience.
The field of behavioral finance focuses on human risk-aversion, asymmetric regret, and other ways that human financial behavior varies from what analysts call "rational". Risk in that case is the degree of uncertainty associated with a return on an asset.
Recognizing and respecting the irrational influences on human decision making may do much to reduce disasters caused by naive risk assessments that pretend to rationality but in fact merely fuse many shared biases together.
Since Risk assessment and management is essential in security management, both are tightly related. Security assessment methodologies like BEATO or CRAMM contain risk assessment modules as an important part of the first steps of the methodology. On the other hand, Risk Assessment methodologies, like Mehari evolved to become Security Assessment methodologies. A ISO standard on risk management (Principles and guidelines on implementation) is currently being draft under code ISO/DIS 31000. Target publication date 30 May 2009.
Where AR is audit risk, IR is inherent risk, CR is control risk and DR is detection risk.