5 Marzo 2007 INNOVATIONS IN CENSUS MAPPING AND CENSUS DATA GEOCODING Fabio Crescenzi Istat, Central Directorate on General Censuses Joint UNECE/Eurostat Meeting on Population and Housing Censuses (Astana, 4-6 June 2007)

New approaches in census methodologies 2/19 Several Countries moved from traditional to new approaches, as: -Register-based -Combination of conventional census and sample survey, -Combination of register based census and sample survey, -Rolling sample, Etc. etc.

Istat Reorganization 3/19 The Board of the National Institute of Statistics of Italy, in occasion of the 2006 reorganisation of the Institute, established a new directorate, the Central Directorate for General Censuses (DCCG). Mandate of DCCG: The mandate of DCCG, is to determine pros and cons of new approaches, emerging census methodologies and techniques, organizational options, to allow to take the most appropriate decisions for the next census round in Italy.

Critical factors in explaining the quality of census data 4/19 Demographic size of municipalities emerged as one of the most important risk factor in recent census round. Offices of the larger-sized municipalities, in a relatively short period, have to face a huge increase in human resources to be trained and employed in census fieldwork.

Classification by demographic size 5/19 Large size municipalities: At least inhabitants (including all major city of province also if < inhabitants). 159 municipalities, 36% of Italian population Medium size municipalities: At least inhabitants, excluding large size municipalities 953 municipalities, 31% of Italian population Small size municipalities: Others municipalities municipalities, 33% of Italian population

Tasks of Municipality Offices 6/19 According to the Regolamento Anagrafico (D.P.R. n.223 del 30 maggio 1989), Istat, Metodi e Norme serie B – n , have the task to maintain: a)the boundaries and codes of census mapping units (enumeration areas and localities) in the latest version validated by the National Institute of Statistics; b)a list of address numbers. The Italian law on population registers. Contents, formats and quality of these data are highly variable

Actions to reduce census burden in large- sized municipality 7/19 -Use in census operations geocoded lists of address numbers -To introduce new areal units in census mapping to allow a Long- Short form approach

Tools available from other National Authorities or private companies 8/19 I case National Address Point System in which each building address is represented by a coordinate in a proper geographic reference system II case National Street Network + Address numbers archive

What it is available in Italy 9/19 - A National Address Point System it is not available -National Street Network are available only from commercial sources. -Many large-sized municipalities developed Local Address Point Systems and Local Street Networks.

10/19 In advance of enumerators fieldwork using local Address Point Systems or local information on addresses, to produce, at least in the larger-sized municipalities, a comprehensive list of address numbers geocoded to Eas First possible innovation for the next census round

What we are doing 11/19 Pilot projects. Launch of pilot projects of local and commercial sources integration to build experimental integrated archives. In 2006 Firenze, Bologna. In 2007 several municipalities, as Cuneo, Milano, Palermo, Pesaro, Trapani, etc Web survey. A web survey on large and medium sized municipalities was recently launched to know precisely contents, formats, and characteristics of geographical data, including lists of georeferenced addresses, street network, etc, available at municipality level.

Geoocoded addresses employ 12/19 a)to find EA in which at least a pre-determined number of new address numbers have been created after last census and consequently need to be redesigned in the census mapping update; b)to keep under control the expected number of buildings in each EA; c)to preprint lists of address numbers for enumerators; d)to allow enumerators to find, to enumerate and to survey statistical units; e)to allow fieldwork and centralized check of coverage.

Census Mapping 13/19 Defining the census mapping is a crucial pre- enumeration work having big consequences on census management and enumerators fieldwork Main objective of this work are: to define lists of territorial units included in the census geographic hierarchy, to delineate their borders, to define the coding schemes, to code each unit. Usually the census geographic hierarchy includes three level: 1) Administrative borders (Country, Regions, Provinces, Municipalities); Localities (Morphological Areas); 3) Enumeration Areas (EAs)

Innovations of the last two decades 14/19 1)A comprehensive census mapping databases in digital format was built; 2)Census mapping was improved using as possible new available images, other cartographic sources and Gis applications.

Next round census mapping innovations 15/19 delineate Census Areas in large and medium sized municipalities to allow in the main locality of large and medium sized municipalities the use of Long and Short Forms sampling techniques. Employ as possible web in census mapping delineation

Census Areas 16/19 -will represent a new unit in the mapping hierarchy between the main locality of the municipality, and the EAs. -will be delineated in partnership with municipalities offices and will be compatible as possible with areas defined at municipality level (Municipality Areas), as wards, functional zones, etc. -the target population size is inhabitants, the target expected range in population sizes is inhabitants.

Steps to build Census Areas 17/19 First step: Basic Areas definition. Basic Areas are obtained by overlay of first order natural features and municipality areas boundaries. Second step: From Basic to Census Areas. It is verified if a Basic Area may be taken as a Census Area, an area in which is possible to employ sampling techniques, or if it is possible to merge contiguous Basic Areas to form a Census Area,.

Census area employ 18/19 The Census Areas, so delineated, may allow: -the adoption of sample strategies as Long-Short form. -in fieldwork organization, could be employed as supervisory area, a set of contiguous EAs to be assigned to one supervisor. -may be employed as output areas or reporting zones in census data dissemination. -in a medium term perspective may be target zones on which, starting from census outputs, increase local data availability integrating existing data from local sources.

What we are doing 19/19 Pilot projects. Launch of pilot projects to build experimental Census Areas. Firenze, Bologna, Milano, etc Web survey. Some questions to large-medium sized municipalities to know areas defined at municipality level (Municipality Areas), as wards, functional zones, etc.