Observational errorObservational error (or measurement error) is the difference between a measured value of a quantity and its true value. In statistics, an error is not necessarily a "mistake". Variability is an inherent part of the results of measurements and of the measurement process. Measurement errors can be divided into two components: random and systematic. Random errors are errors in measurement that lead to measurable values being inconsistent when repeated measurements of a constant attribute or quantity are taken.
Parametric modelIn statistics, a parametric model or parametric family or finite-dimensional model is a particular class of statistical models. Specifically, a parametric model is a family of probability distributions that has a finite number of parameters. A statistical model is a collection of probability distributions on some sample space. We assume that the collection, P, is indexed by some set Θ. The set Θ is called the parameter set or, more commonly, the parameter space.
Resale price maintenanceResale price maintenance (RPM) or, occasionally, retail price maintenance is the practice whereby a manufacturer and its distributors agree that the distributors will sell the manufacturer's product at certain prices (resale price maintenance), at or above a price floor (minimum resale price maintenance) or at or below a price ceiling (maximum resale price maintenance). If a reseller refuses to maintain prices, either openly or covertly (see grey market), the manufacturer may stop doing business with it.
Generalized chi-squared distributionIn probability theory and statistics, the generalized chi-squared distribution (or generalized chi-square distribution) is the distribution of a quadratic form of a multinormal variable (normal vector), or a linear combination of different normal variables and squares of normal variables. Equivalently, it is also a linear sum of independent noncentral chi-square variables and a normal variable. There are several other such generalizations for which the same term is sometimes used; some of them are special cases of the family discussed here, for example the gamma distribution.
Equity derivativeIn finance, an equity derivative is a class of derivatives whose value is at least partly derived from one or more underlying equity securities. Options and futures are by far the most common equity derivatives, however there are many other types of equity derivatives that are actively traded. Option (finance) Equity options are the most common type of equity derivative. They provide the right, but not the obligation, to buy (call) or sell (put) a quantity of stock (1 contract = 100 shares of stock), at a set price (strike price), within a certain period of time (prior to the expiration date).
Mann–Whitney U testIn statistics, the Mann–Whitney U test (also called the Mann–Whitney–Wilcoxon (MWW/MWU), Wilcoxon rank-sum test, or Wilcoxon–Mann–Whitney test) is a nonparametric test of the null hypothesis that, for randomly selected values X and Y from two populations, the probability of X being greater than Y is equal to the probability of Y being greater than X. Nonparametric tests used on two dependent samples are the sign test and the Wilcoxon signed-rank test.
Passive managementPassive management (also called passive investing) is an investing strategy that tracks a market-weighted index or portfolio. Passive management is most common on the equity market, where index funds track a stock market index, but it is becoming more common in other investment types, including bonds, commodities and hedge funds. The most popular method is to mimic the performance of an externally specified index by buying an index fund.
Exchange-traded fundAn exchange-traded fund (ETF) is a type of investment fund and exchange-traded product, i.e. they are traded on stock exchanges. ETFs own financial assets such as stocks, bonds, currencies, futures contracts, and/or commodities such as gold bars. The list of assets that each ETF owns, as well as their weightings, is posted on the website of the issuer daily, or quarterly in the case of active non-transparent ETFs. Many ETFs provide some level of diversification compared to owning an individual stock.
Nassim Nicholas TalebNassim Nicholas Taleb (ˈtɑːləb; alternatively Nessim or Nissim; born 12 September 1960) is a Lebanese-American essayist, mathematical statistician, former option trader, risk analyst, and aphorist whose work concerns problems of randomness, probability, and uncertainty. Taleb is the author of the Incerto, a five-volume philosophical essay on uncertainty published between 2001 and 2018 (notably, The Black Swan and Antifragile).
Model riskIn finance, model risk is the risk of loss resulting from using insufficiently accurate models to make decisions, originally and frequently in the context of valuing financial securities. However, model risk is more and more prevalent in activities other than financial securities valuation, such as assigning consumer credit scores, real-time probability prediction of fraudulent credit card transactions, and computing the probability of air flight passenger being a terrorist.
