Ricerc@Sapienza

Handling populations' heterogeneity is a common issue in capture-recapture problems. To correctly estimate a target population's size, the possibility of heterogeneity, i.e. that capture probabilities vary among individuals, must be considered. Such difference in capture probabilities might be due to different "weights" the groups within the target populations have in the various capture occasions. Noncentral Hypergeometric (NH) distributions arise naturally in situations where units in the population that are sampled without replacement have different probabilities of being drawn. Such distributions have been underemployed in the statistical literature mainly because of the computational complexity given by their densities. Nevertheless, modern computational tools allow for the exploitation of such distributions, that are easily applicable in a variety of contexts. This project's aim is to give Fisher's NH distribution a new vest, using it in an official statistics context.