CoViD--19: An Automatic, Semiparametric Estimation Method for the Population Infected in Italy

Livio Fenga

The bootstrap scheme adopted proved to be a real asset for the problem at hand. Given the pivotal role played it will be briefly presented. In essence, the choice of the most appropriate resampling method is far from being an easy task, especially when the identical and independent distribution iid assumption (Efron's initial bootstrap method) is violated. Under dependence structures embedded in the data, simple sampling with replacement has been proved -see, for example Carlstein et al. (1986) -to yield suboptimal results. As a matter of fact, iid-based bootstrap schmes are not designed to capture, and therefore replicate, dependence structures. This is especially true under the actual conditions (small sample sizes). In such cases, selecting the "right" resampling scheme becomes a particularly challenging task. Several ad hoc methods have been therefore Page 3 of 14 . CC-BY-NC-ND 4.0 International license It is made available under a author/funder, who has granted medRxiv a license to display the preprint in perpetuity.