What is generally described as the Stoppa distribution is the second of five types. Three of the five were also published by others, are better known under different titles and so described elsewhere in this book.
The Stoppa‐I distribution is commonly known as the power distribution, described later in Section 33.20.
The Stoppa‐II distribution is one of three generalisations of the Pareto‐I distribution, defined by adding the shape parameter (δ2). Its PDF is
The CDF is
Fitting to the NHV disturbance data gives values for β, δ1 and δ2 are respectively 0, 1.01 and 379. With RSS at 0.2108 the fit is an improvement on the standard Pareto distribution but is still poor – as shown by Figure 24.2.
Inverting gives the QF ...