Notation  

Parameters 
μ ∈ R — location, σ > 0 — scale, ξ ∈ R — shape.  
Support 
x ∈ [ μ − σ / ξ, +∞) when ξ > 0, x ∈ (−∞, +∞) when ξ = 0, x ∈ (−∞, μ − σ / ξ ] when ξ < 0.  
where  
CDF  for x ∈ support  
Mean 
where g_{k} = Γ(1 − kξ), and is Euler’s constant.  
Median  
Mode  
Variance  .  
Skewness 
where is the sign function and is the Riemann zeta function  
Ex. kurtosis  
Entropy  
MGF  ^{[1]}  
CF  ^{[1]} 
In probability theory and statistics, the generalized extreme value (GEV) distribution is a family of continuous probability distributions developed within extreme value theory to combine the Gumbel, Fréchet and Weibull families also known as type I, II and III extreme value distributions. By the extreme value theorem the GEV distribution is the only possible limit distribution of properly normalized maxima of a sequence of independent and identically distributed random variables. Note that a limit distribution need not exist: this requires regularity conditions on the tail of the distribution. Despite this, the GEV distribution is often used as an approximation to model the maxima of long (finite) sequences of random variables.
In some fields of application the generalized extreme value distribution is known as the Fisher–Tippett distribution, named after Ronald Fisher and L. H. C. Tippett who recognised three different forms outlined below. However usage of this name is sometimes restricted to mean the special case of the Gumbel distribution. The common functional form for all 3 distributions was discovered by McFadden in 1978.^{[2]}
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Transcription
Contents
Specification
Using the standardized variable , where is the location parameter and is the scale parameter, the cumulative distribution function of the GEV distribution is
where is the shape parameter. Thus for , the expression is valid for , while for it is valid for . In the first case, at the lower endpoint, it equals 0; in the second case, at the upper endpoint, it equals 1. For the first expression is formally undefined and is replaced with the result obtained by taking the limit as in which case .
If then and ≈ whatever the values of and
The probability density function of the standardized distribution is
again valid for in the case , and for in the case . The density is zero outside of the relevant range. In the case the density is positive on the whole real line.
Since the cumulative distribution function is invertible, the quantile function for the GEV distribution has an explicit expression, namely
and therefore the quantile density function is
Summary statistics
Some simple statistics of the distribution are:^{[citation needed]}
 for
The skewness is for ξ>0
For ξ<0, the sign of the numerator is reversed.
The excess kurtosis is:
where , k=1,2,3,4, and is the gamma function.
Link to Fréchet, Weibull and Gumbel families
The shape parameter governs the tail behavior of the distribution. The subfamilies defined by , and correspond, respectively, to the Gumbel, Fréchet and Weibull families, whose cumulative distribution functions are displayed below.
 Gumbel or type I extreme value distribution ()
 Fréchet or type II extreme value distribution, if and
 Reversed Weibull or type III extreme value distribution, if and
The subsections below remark on properties of these distributions.
Modification for minima rather than maxima
The theory here relates to data maxima and the distribution being discussed is an extreme value distribution for maxima. A generalised extreme value distribution for data minima can be obtained, for example by substituting (−x) for x in the distribution function, and subtracting from one: this yields a separate family of distributions.
Alternative convention for the Weibull distribution
The ordinary Weibull distribution arises in reliability applications and is obtained from the distribution here by using the variable , which gives a strictly positive support  in contrast to the use in the extreme value theory here. This arises because the ordinary Weibull distribution is used in cases that deal with data minima rather than data maxima. The distribution here has an addition parameter compared to the usual form of the Weibull distribution and, in addition, is reversed so that the distribution has an upper bound rather than a lower bound. Importantly, in applications of the GEV, the upper bound is unknown and so must be estimated, while when applying the ordinary Weibull distribution in reliability applications the lower bound is usually known to be zero.
Ranges of the distributions
Note the differences in the ranges of interest for the three extreme value distributions: Gumbel is unlimited, Fréchet has a lower limit, while the reversed Weibull has an upper limit. More precisely, Extreme Value Theory (Univariate Theory) describes which of the three is the limiting law according to the initial law X and in particular depending on its tail.
Distribution of log variables
One can link the type I to types II and III the following way: if the cumulative distribution function of some random variable is of type II, and with the positive numbers as support, i.e. , then the cumulative distribution function of is of type I, namely . Similarly, if the cumulative distribution function of is of type III, and with the negative numbers as support, i.e. , then the cumulative distribution function of is of type I, namely .
Link to logit models (logistic regression)
Multinomial logit models, and certain other types of logistic regression, can be phrased as latent variable models with error variables distributed as Gumbel distributions (type I generalized extreme value distributions). This phrasing is common in the theory of discrete choice models, which include logit models, probit models, and various extensions of them, and derives from the fact that the difference of two typeI GEVdistributed variables follows a logistic distribution, of which the logit function is the quantile function. The typeI GEV distribution thus plays the same role in these logit models as the normal distribution does in the corresponding probit models.
Properties
The cumulative distribution function of the generalized extreme value distribution solves the stability postulate equation.^{[citation needed]} The generalized extreme value distribution is a special case of a maxstable distribution, and is a transformation of a minstable distribution.
Applications
 The GEV distribution is widely used in the treatment of "tail risks" in fields ranging from insurance to finance. In the latter case, it has been considered as a means of assessing various financial risks via metrics such as Value at Risk.^{[3]}^{[4]}
 However, the resulting shape parameters have been found to lie in the range leading to undefined means and variances, which underlines the fact that reliable data analysis is often impossible.^{[6]}
 In hydrology the GEV distribution is applied to extreme events such as annual maximum oneday rainfalls and river discharges. The blue picture, made with CumFreq, illustrates an example of fitting the GEV distribution to ranked annually maximum oneday rainfalls showing also the 90% confidence belt based on the binomial distribution. The rainfall data are represented by plotting positions as part of the cumulative frequency analysis.
Related distributions
 If then
 If (Gumbel distribution) then
 If (Weibull distribution) then
 If then (Weibull distribution)^{[citation needed]}
 If (Exponential distribution) then ^{[citation needed]}
 If and then (see Logistic_distribution).
 If and then (The sum is not a logistic distribution). Note that .
See also
 Extreme Value Theory (Univariate Theory)
 Fisher–Tippett–Gnedenko theorem
 Generalized Pareto distribution
 German tank problem, opposite question of population maximum given sample maximum
 Pickands–Balkema–de Haan theorem
Notes
 ^ ^{a} ^{b} Muraleedharan. G, C. Guedes Soares and Cláudia Lucas (2011). "Characteristic and Moment Generating Functions of Generalised Extreme Value Distribution (GEV)". In Linda. L. Wright (Ed.), Sea Level Rise, Coastal Engineering, Shorelines and Tides, Chapter14, pp. 269–276. Nova Science Publishers. ISBN 9781617286551
 ^ McFadden, Daniel (1978). "Modeling the Choice of Residential Location" (PDF). Transportation Research Record (673): 72–77.
 ^ Moscadelli, Marco. "The modelling of operational risk: experience with the analysis of the data collected by the Basel Committee." Available at SSRN 557214 (2004).
 ^ Guégan, D.; Hassani, B.K. (2014), "A mathematical resurgence of risk management: an extreme modeling of expert opinions", Frontiers in Finance and Economics, 11 (1): 25–45, SSRN 2558747
 ^ CumFreq for probability distribution fitting [1]
 ^ Kjersti Aas, lecture, NTNU, Trondheim, 23 Jan 2008
References
 Embrechts, Paul; Klüppelberg, Claudia; Mikosch, Thomas (1997). Modelling extremal events for insurance and finance. Berlin: Springer Verlag.
 Leadbetter, M.R., Lindgren, G. and Rootzén, H. (1983). Extremes and related properties of random sequences and processes. SpringerVerlag. ISBN 0387907319.CS1 maint: multiple names: authors list (link)
 Resnick, S.I. (1987). Extreme values, regular variation and point processes. SpringerVerlag. ISBN 0387964819.
 Coles, Stuart (2001). An Introduction to Statistical Modeling of Extreme Values,. SpringerVerlag. ISBN 1852334592.