Starting from 2001 Population census data three files have been designed in order to study the total usually resident population constituted by “usually resident persons in Household” and by “usually resident persons in Institutional households”:
– the households file, in which each record represents a person belonging to a household. All the household members are included in the file. Each record is linked to a unique code/identification number that allows to piece together the household. The size of this file is about the 5.25 per cent of the population (2,969,561 individual records belonging to 1,146,868 households). The information is available at NUTS2 territorial level (Piemonte and Valle d’Aosta are merged);
– the dwellings file, with information about dwellings occupied by the households included in the households file. The file contains 1,146,382 records. Each of them represents a dwelling linkable to the matching household by a code linkage;
– the institutional households file, including 21,178 individual records without hierarchical relationships. So, the affiliation to the same institutional household is not possible.