[Forum SIS] Seminario di Stefano Favaro, CNR IMATI, Milano

[Antonio Pievatolo]

Il prof Stefano Favaro terrà un seminario al CNR-IMATI, sede di Milano, 
mercoledì 13/6/2018 alle 14:30, via Alfonso Corti 12, aula A. Chi 
intendesse partecipare è pregato di comunicarlo a 
simona.milani at mi.imati.cnr.it per ragioni organizzative.

Cordialmente

A. Pievatolo

%%%%%%%%% titolo e abstract %%%%%%%%%%%

A Bayesian approach to disclosure risk assessment

Protection against disclosure is a legal and ethical obligation for 
statistical agencies releasing microdata files for public use. Given a 
cross classification of sample records by categorical key variables, any 
decision about release is supported by measures of disclosure risk, the 
most common being the number $\tau_{1}$ of sample uniques cells that are 
also population uniques. In this paper we depart from the dominant 
literature that infers $\tau_{1}$ by modeling association among key 
variables, and we consider modeling directly sample records. We develop 
a novel nonparametric Bayesian approach under the minimal assumption of 
a generalized Dirichlet prior for the random partition induced by the 
cross-classified sample records. This allows to derive an explicit, and 
simple, expression for the posterior distribution of $\tau_{1}$, as well 
as a large sample Binomial approximation of it. Such a closed-form 
results, combined with an estimator for prior parameters designed in 
such a way to recognizes a primary role of small cells, make inference 
on $\tau_{1}$ exact, of easy implementation, computationally efficient 
and scalable to massive datasets. The proposed approach is tested on 
benchmark data from the U.S. 2000 census for the state of California, 
showing the same good performance of recent semiparametric Bayesian 
models for key variables.

-- 
Dr Antonio Pievatolo
IMATI-CNR
http://www.imati.cnr.it/joomla/index.php/people?layout=edit&id=101