In
probability theory
Probability theory is the branch of mathematics concerned with probability. Although there are several different probability interpretations, probability theory treats the concept in a rigorous mathematical manner by expressing it through a set o ...
,
statistics and
econometrics
Econometrics is the application of statistical methods to economic data in order to give empirical content to economic relationships.M. Hashem Pesaran (1987). "Econometrics," '' The New Palgrave: A Dictionary of Economics'', v. 2, p. 8 p. 8� ...
, the Burr Type XII distribution or simply the Burr distribution is a
continuous probability distribution for a non-negative
random variable
A random variable (also called random quantity, aleatory variable, or stochastic variable) is a mathematical formalization of a quantity or object which depends on random events. It is a mapping or a function from possible outcomes (e.g., the p ...
. It is also known as the Singh–Maddala distribution and is one of a number of different distributions sometimes called the "generalized
log-logistic distribution". It is most commonly used to model
household income, see for example:
Household income in the U.S. and compare to
magenta
Magenta () is a color that is variously defined as pinkish- purplish- red, reddish-purplish-pink or mauvish- crimson. On color wheels of the RGB (additive) and CMY (subtractive) color models, it is located exactly midway between red and bl ...
graph at right.
The Burr (Type XII) distribution has
probability density function
In probability theory, a probability density function (PDF), or density of a continuous random variable, is a function whose value at any given sample (or point) in the sample space (the set of possible values taken by the random variable) c ...
:
:
and
cumulative distribution function
In probability theory and statistics, the cumulative distribution function (CDF) of a real-valued random variable X, or just distribution function of X, evaluated at x, is the probability that X will take a value less than or equal to x.
Ev ...
:
:
:
Related distributions
* When ''c'' = 1, the Burr distribution becomes the
Pareto Type II (Lomax) distribution.
* When ''k'' = 1, the Burr distribution is a
log-logistic distribution sometimes referred to as the
Fisk distribution, a special case of the
Champernowne distribution.
* The Burr Type XII distribution is a member of a system of continuous distributions introduced by
Irving W. Burr (1942), which comprises 12 distributions.
[See Kleiber and Kotz (2003), Table 2.4, p. 51, "The Burr Distributions."]
* The
Dagum distribution, also known as the inverse Burr distribution, is the distribution of 1 / ''X'', where ''X'' has the Burr distribution
References
Further reading
*
{{DEFAULTSORT:Burr Distribution
Continuous distributions