摘要：The current literature on so-called ‘skew-symmetric distributions’ is closely linked to the idea of a selection mechanism operated by some latent variable. We illustrate the pioneering work of Fernando de Helguero who in 1908 put forward a formulation for the genesis of non-normal distributions via a selection mechanism, which perturbs a normal distribution, hence employing a closely connected argument with the one now widely used in this context. Arguably, de Helguero can then be considered the precursor of the current idea of skew-symmetric distributions. Unfortunately, a tragic quirk of fate did not allow him to pursue his project beyond the initial formulation and his work went unnoticed for the rest of the 20th century.
关键词：Hidden truncation model · History of statistics · Selection models;· Selective sampling · Skew-normal distribution · Weighted distributions.tions.
