dreifingarbreytingar
Dreifingarbreytingar is a term used in Icelandic statistics and related fields to describe changes in the distribution of a variable. It covers any alteration in the probability distribution, including shifts in location (mean), changes in scale (variance), and changes in shape (skewness and kurtosis), as well as more complex alterations such as mixing of distributions or changes in the entire functional form.
In practice, dreifingarbreytingar are analyzed by comparing distributions across time, groups, or conditions. Common approaches include
Mathematically, if X has a distribution F, a dreifingarbreyting can occur through a transformation Y = g(X)
Applications of dreifingarbreytingar include assessing the impact of policies on income or wealth distributions, tracking epidemiological
See also: Probability distribution; Transformation of random variables; Kolmogorov–Smirnov test; quantile regression; GAMLSS.