Uncertainty refers to epistemic situations involving imperfect or unknown information. It applies to predictions of future events, to physical measurements that are already made, or to the unknown. Uncertainty arises in partially observable or stochastic environments, as well as due to ignorance, indolence, or both. It arises in any number of fields, including insurance, philosophy, physics, statistics, economics, finance, medicine, psychology, sociology, engineering, metrology, meteorology, ecology and information science.
Value at risk (VaR) is a measure of the risk of loss of investment/Capital. It estimates how much a set of investments might lose, given normal market conditions, in a set time period such as a day. VaR is typically used by firms and regulators in the financial industry to gauge the amount of assets needed to cover possible losses.
Frank Hyneman Knight was an American economist who spent most of his career at the University of Chicago, where he became one of the founders of the Chicago School.
Common and special causes are the two distinct origins of variation in a process, as defined in the statistical thinking and methods of Walter A. Shewhart and W. Edwards Deming. Briefly, "common causes", also called natural patterns, are the usual, historical, quantifiable variation in a system, while "special causes" are unusual, not previously observed, non-quantifiable variation.
Nassim Nicholas Taleb is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist whose work concerns problems of randomness, probability, and uncertainty.
In decision theory, the Ellsberg paradox is a paradox in which people's decisions are inconsistent with subjective expected utility theory. Daniel Ellsberg popularized the paradox in his 1961 paper, "Risk, Ambiguity, and the Savage Axioms". John Maynard Keynes published a version of the paradox in 1921. It is generally taken to be evidence of ambiguity aversion, in which a person tends to prefer choices with quantifiable risks over those with unknown, incalculable risks.
Entrepreneurial economics is the study of the entrepreneur and entrepreneurship within the economy. The accumulation of factors of production per se does not explain economic development. They are necessary factors of production, but they are not sufficient for economic growth.
A fat-tailed distribution is a probability distribution that exhibits a large skewness or kurtosis, relative to that of either a normal distribution or an exponential distribution. In common usage, the terms fat-tailed and heavy-tailed are sometimes synonymous; fat-tailed is sometimes also defined as a subset of heavy-tailed. Different research communities favor one or the other largely for historical reasons, and may have differences in the precise definition of either.
George Lennox Sharman Shackle was an English economist. He made a practical attempt to challenge classical rational choice theory and has been characterised as a "post-Keynesian", though he is influenced as well by Austrian economics. Much of his work is associated with the Dempster–Shafer theory of evidence.
Financial risk modeling is the use of formal mathematical and econometric techniques to measure, monitor and control the market risk, credit risk, and operational risk on a firm's balance sheet, on a bank's trading book, or re a fund manager's portfolio value; see Financial risk management. Risk modeling is one of many subtasks within the broader area of financial modeling.
The ambiguity effect is a cognitive bias where decision making is affected by a lack of information, or "ambiguity". The effect implies that people tend to select options for which the probability of a favorable outcome is known, over an option for which the probability of a favorable outcome is unknown. The effect was first described by Daniel Ellsberg in 1961.
In decision theory and economics, ambiguity aversion is a preference for known risks over unknown risks. An ambiguity-averse individual would rather choose an alternative where the probability distribution of the outcomes is known over one where the probabilities are unknown. This behavior was first introduced through the Ellsberg paradox.
The black swan theory or theory of black swan events is a metaphor that describes an event that comes as a surprise, has a major effect, and is often inappropriately rationalized after the fact with the benefit of hindsight. The term is based on an ancient saying that presumed black swans did not exist, until they were discovered in Australia in 1697, and it then became reinterpreted to mean an unforeseen and consequential event.
The Black Swan: The Impact of the Highly Improbable is a 2007 book by Nassim Nicholas Taleb, who is a former options trader. The book focuses on the extreme impact of rare and unpredictable outlier events—and the human tendency to find simplistic explanations for these events, retrospectively. Taleb calls this the Black Swan theory.
In economics and finance, a Taleb distribution is the statistical profile of an investment which normally provides a payoff of small positive returns, while carrying a small but significant risk of catastrophic losses. The term was coined by journalist Martin Wolf and economist John Kay to describe investments with a "high probability of a modest gain and a low probability of huge losses in any period."
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value, often focusing on negative, undesirable consequences. Many different definitions have been proposed. The international standard definition of risk for common understanding in different applications is "effect of uncertainty on objectives".
Mathematical finance, also known as quantitative finance and financial mathematics, is a field of applied mathematics, concerned with mathematical modeling of financial markets.
The term kaleidics denotes the ever-changing shape and status of an economy. Uncertainty is the primary kaleidic factor. It is strongly associated with the work of George Shackle, who had a rather radical interpretation of Keynesian economic theory. He surmised that the uncertainty in a capitalist economy was due to the irrational nature of investment, which is often driven by irrational fears, rumors, and superstition, rather than what is traditionally assumed to be cold, hard, calculation. Such theories lead to the view, expressed in Viennese kaleidics, that the turbulence of markets cannot be smoothed through government interference, and must therefore be left to their own devices.
Antifragile: Things That Gain From Disorder is a book by Nassim Nicholas Taleb published on November 27, 2012, by Random House in the United States and Penguin in the United Kingdom. This book builds upon ideas from his previous works including Fooled by Randomness (2001), The Black Swan (2007–2010), and The Bed of Procrustes (2010–2016), and is the fourth book in the five-volume philosophical treatise on uncertainty titled Incerto. Some of the ideas are expanded on in Taleb's fifth book Skin in the Game: Hidden Asymmetries in Daily Life (2018).
Skin in the Game: Hidden Asymmetries in Daily Life is a 2018 nonfiction book by Nassim Nicholas Taleb, a former options trader with a background in the mathematics of probability and statistics.
