12.6 Household address register#
12.6.1 Roles and benefits of address register#
A statistical household address register contains organized contact information for every household. It can be generated from census or administrative information, but it is most commonly generated by combining census with administrative address information.
Administrative address information, with official names of streets, is usually in the jurisdiction of the local government and only in rare cases is subject to central government intervention. Even though street/block names and numbers are administrative information, the degree to which they are standardised and encoded varies greatly between countries. Some countries do not have a database of street names, while other spatial units (including dwellings) are codified to the greatest detail and regularly updated.
Codifying spatial units generally depends on national practices and administrative traditions. Recent attempts for international standardisation have been made through the UN-GGIM by developing the Integrated Geospatial Information Framework (IGIF), aiming to bring a spatial component into every data layer of the government. The importance of spatial information and GIS systems for official statistics is emphasised and further elaborated in Chapter 9.4 — Geospatial data.
NSOs, particularly those in charge of census taking, have a direct interest in the quality of address information. Thus, they have (with different results) managed to influence administrative bodies to improve (and standardise) the address information systems. Key to maintaining a high-quality statistical address register is having access to administrative data that is regularly updated. Unfortunately, building registration is often a complicated administrative process that involves multiple institutions and involves different procedures (safety, administrative, cadastral, taxation, etc.) and may therefore be difficult to influence. Census preparation may provide an excellent opportunity to start the standardisation process between different institutions. Each standardisation usually requires many discussions, but the key to success is agreeing to use a common identification number. Presentation Building and dwelling register as a base for the production of geostatistical data (🔗) by Swiss Federal Statistics Office provides an illustrative overview of the path that has to be taken by an NSO that wishes to promote a standardised approach through government administration.
In most advanced countries an address register is geocoded, each entry has a unique ID and is a member of multiple spatial hierarchies (street & house number, census area, school district, court district, hospital jurisdiction, etc.). Further, in some countries, an address register contains information about every building and every dwelling (apartment) inside every building. In some countries (i.e., Ireland) unique postal codes are assigned to each dwelling. This is commonly referred to as buildings and dwellings register. Dwellings registers often contain other properties such as surface area, floor, number of rooms, utility access, number of occupants and others.
Having a reliable address register improves survey data quality and reduces the data collection costs, as it eliminates the need for area enumeration/household listing (which is usually performed before Census or other major surveys).
Countries that do not have access to high-quality administrative information on dwellings and their occupancy have sought to supplement address information with additional sources. This approach is often referred to as multi-source household address register where administrative information on addresses (that may or may not include dwelling (apartment) numbers) is supplemented with information from utility companies, tax returns or other sources of information. Household address registers provide a tabular list frame that can be used for household surveys and population censuses, it reduces the costs of the Census as it eliminates the need for address canvassing and increases quality of the data through increased coverage, particularly if Census is conducted via the mail-in method.
In preparation for the 2020 Census round, some countries have started using Big Data approaches to gather information needed to update the household address register. Through agreements with post offices, they have started processing postal address information to update their address registers. Further, most offices perform in-office address canvassing using satellite imagery, thus significantly reducing the number of addresses that have to be canvassed in-field before the Census. An overview of the approach used by the Australian Bureau of Statistics to maintain and update Address Register, including issues relating to the preservation of privacy can be found here.
Furthermore, one of the major recommendations of the 2020 World Population and Housing Census Programme, launched in 2015, refers to the advantages of geo-referencing individual housing units, resulting in a housing unit register that can be later reconciled with address register.
Albeit in some developing countries, the completeness of the address register does not usually extend beyond major urban areas. The housing unit register would then be used as a major sampling frame for subsequent surveys and other statistical data collection exercises.
12.6.2 Conceptual framework#
Even though neither a coherent conceptual framework nor an international standard for address registers exists, related concepts can be found in various places. Handbook on geospatial infrastructure in support of Census activities (🔗) provides guidance on organizing address information for census purposes, while the Integrated Geospatial Information Framework (IGIF) and its much more detailed European equivalent INSPIRE (Infrastructure for Spatial Information in Europe) Directive (🔗) and various national versions provide broader frameworks.
12.6.3 Sources and maintenance procedures#
Countries that have developed administrative dwellings registers define their setup and maintenance procedures through legislative measures. A setup procedure is usually based on updated cadastral information through a specified administrative process or field recording of dwellings. The update procedure is also defined by law and includes adding and deactivating identifiers with addition/removal of every dwelling from the registry. Countries that do not have administrative dwellings and/or population registers usually construct household address registers before the census by supplementing the administrative and postal list of addresses with contact information from other sources, but there are examples where this process is performed continuously.
Usual sources for updating the information are utility and phone companies’ information, tax forms, emergency services, tv licences and similar structured databases.
The process usually involves multiple phases, where data from multiple sources is connected, cleaned and geocoded by using algorithmic tools and then controlled and corrected on the field, either by local authorities, statistical offices or external contractors. A modern approach to the process is creating a web-based address interface that enables address control and correction.
The quality of the household address register depends not only on the quality of the administrative address information but also on the quality of supplementing information. Quality of data depends on the registration process’s quality but is often influenced by legal traditions, compliance and trust in institutions.
12.6.4 Generation of household survey frames#
Household address registers can be used as directly survey frames or used to generate frames for specific surveys. A household address register is basically a list frame that lists all units in the survey population. It also contains information from an area frame, meaning information on the hierarchy of geographical areas as units. This feature of a household address register allows for two-stage sample selection, in which units are first selected from the area frame and then from the list frame only for previously selected areas.
Household address registers can be used as frames for population censuses because they contain identifying information for all census units. Further, household address register can be an excellent aid in census preparation, as they allow efficient fieldwork planning.
Unfortunately, ordinary household address registers generally do not contain information about their occupants and can therefore rarely be used for sample stratification. Population registers, on the other hand, can also serve this purpose. They can support:
Specification of survey population;
Derivation of survey frames;
Selection of survey samples.
Fritz Scheuren - Administrative records and census taking, Survey methodology vol 25, DEC 1999 (🔗);
The creation of a Residential Address Register for Coverage Improvement in the 1991 Canadian Census (🔗);
ONS - compiling the address register for 2011 Census (🔗);
ONS – local authority partnership programme guide (🔗);
Building an address index for census and beyond - Alistair Calder, ONS (🔗);
Building the address register for the 2011 Census – England and Wales Guidelines on the use of registers and administrative data for population and housing censuses – UNECE (🔗);
Handbook on geospatial infrastructure in support of census activities – UNSD (🔗).