21 December 2001


                                                                                                           English only


Symposium on Global Review of 2000 Round of

Population and Housing Censuses: 

Mid-Decade Assessment and Future Prospects

Statistics Division

Department of Economic and Social Affairs

United Nations Secretariat

New York, 7-10 August 2001







Report on the Symposium on Global Review of 2000 Round of Population and Housing Censuses:

Mid-decade Assessment and Future Prospects


New York: 7-10 August 2001




Summary. 1

A. Introduction. 4

B. Strategies for involving stakeholders in census activities. 4

C.  Strategies for choosing among data collection methods. 5

D. Funding for population and housing censuses. 7

E. Adapting new technologies to census operations. 8

F. Identifying and resolving problems of census mapping. 10

G. Maintaining census-related activities. 11

H. Census data evaluation. 12



Report of the Symposium


1.                  The Symposium on Global Review of the 2000 Round of Population and Housing Censuses addressed the question: “When and under what circumstances do censuses succeed?” It considered problems that have arisen in the current round of censuses (1995-2004) and solutions to overcome these problems, and it discussed how these experiences might guide countries in the planning of the next round of censuses (2005-2014). Discussions focused on several main issues: strategies for involving stakeholders in census activities; strategies for choosing among data-collection methods; funding for censuses; adapting new technologies to census operations; identifying and resolving problems of census mapping; maintaining census-related activities during the intercensal years; and methods of evaluating censuses.


2.                  Census stakeholders are a large and diverse group of data users who may be involved in all aspects of census activity. The key stakeholder groups are government ministries and agencies; provincial, municipal and local governments; private-sector companies and secondary distributors of census data; academic researchers; libraries; non-governmental organizations; media and the general public. Stakeholders help to ensure that relevant data are collected and produced; that the census is understood and supported by the public; that census products are useful and accessible; and that data are of high quality. At the same time, stakeholders have different needs and priorities, which should be balanced against available resources and the suitability of the census to meet specific data needs.


3.                  Participants stressed the importance of identifying key stakeholders and prioritizing their needs. Client requests must be consistent with census procedures in terms of such items as concepts and definitions, transparency, maintaining confidentiality and so forth. Ongoing discussions between stakeholders and the census organization are essential, but, according to a Canadian participant, it is important to keep attention focused on areas where feedback is critical. Stakeholders may contribute to the cost of collecting data for their specific requirements, as is the case in Zambia, as long as the census organization maintains control over census activities. The role of the media is important in creating positive attitudes towards the census, although some countries found that the national media tended to focus on controversial issues. Some topics—for example, HIV/AIDS, illegal activities and disabilities—are sensitive and may not yield satisfactory results when the question is first introduced. In Brazil, a question on disability was asked in the 1991 census. To improve results, data users were consulted early in the process to help frame a more suitable question in 2000.


4.                  The three main sources of demographic and social data are censuses, household surveys and administrative records. In some ways, the census is the primary source because it provides a sampling frame for sample surveys and supplies the population figures that serve as a denominator when calculating vital rates from a civil registration system. Because censuses are expensive and complicated to conduct, there is pressure to limit the basic questionnaire to a few  items and collect more information from a sample of the population. Asking questions on additional topics from a sample of households during a census is a cost-effective way to widen the scope of the census and improve data quality.


5.                  Participants noted the importance of each country’s assessing its particular sources of data and identifying the best method for meeting data needs. When the possibility of linking data from different sources is explored, the use of the same concepts and definitions in different data-collection activities was emphasized to ensure reliability and compatibility of data. Countries with small populations have particular problems in maintaining confidentiality. Alternatives to the census, such as rolling samples and population registers, could also be examined. Development of a population register is a major undertaking and requires reasonably complete registration of births, deaths and other vital events. It also requires a large investment, enabling legislation and the support of the population.


6.                  Technical expertise and financial assistance from international organizations have played an important part in census taking for many developing countries in the past and will continue to be needed in the future. However, as censuses become more expensive and donor funding declines, some countries have been unable to hold censuses on schedule. The discussion centred on identifying new sources of funding, such as public and private national agencies, and conducting more research on ways to reduce the cost of censuses. At the subregional level, participants noted the possibility of coordinating and sharing census activities among groups of neighbouring countries with similar data needs. For example, census organizations could work together to develop core census questionnaires; prepare training manuals; share appropriate data-processing technology; and coordinate dissemination strategies.


7.                  Census technology changes rapidly. When new technology is adopted, an important consideration is ensuring the integrity and continuity of existing census systems. Census managers could avoid choosing the newest or “immature” products, especially if they require extensive pre-testing or if the requisite documentation is unavailable. A good starting point is to examine the most recent census and consider what procedures were successful and which ones could be improved. Census managers agreed on the need for caution about replacing an approach that has worked well in the past. Making decisions about adopting new technologies means having technical awareness, a sense of what can realistically be accomplished, a methodical approach and ample preparation time. Census managers may also learn a great deal from the experiences of other census organizations. Some participants questioned whether census organizations are really adapting new technologies to census taking or whether the new technologies are changing the nature of the census operation.


8.                  Technology can improve the management of census tasks in many areas, from the use of mobile telephones for better communication in the field to bar codes on census materials to facilitate and track their movement. Intelligent Character Recognition (ICR) technology has seen widespread use during the current census round, but some countries have reported problems with scanning hand-written characters. Participants noted that even with extensive training, sufficient supplies and appropriate printers and scanners, ICR technology can sometimes be difficult to implement. Online dissemination of census data via the Internet is also becoming popular, although demand for printed publications is still strong. The Internet may be increasing awareness of and demand for census data. Another area of census operations that has benefited from new information technology is data archiving and storage.


9.                  Census mapping has also seen rapid advances in technology, including Geographic Information System (GIS), digital remote sensing and Global Positioning System (GPS). But many countries still lack up-to-date base maps, which are crucial for a census-mapping programme. Some cartographic units underestimated the time and resources required to produce enumeration maps. GIS technology has widened the scope of census work, and census managers need to consider what standards of accuracy to apply in the maps they produce for census operations.


10.              Census organizations in most countries have established permanent, self-contained cartographic units, but in a few cases, the unit virtually ceases to exist after enumeration is complete. Maintaining and updating maps is vital to the success of a census and is necessary to produce a national master sampling frame for sample surveys. New technology can enhance the versatility and usefulness of census data; census information can be combined with underlying base maps, which permit users to generate thematic maps to meet their own requirements. Participants expressed interest in continuing to share experience and information on developments in mapping technology through web linking and other means.


11.              Census-related activities during the intercensal years provide a smooth transition from one census to another and maintain an institutional memory. Intercensal activities include providing services to data users; updating administrative boundary changes; carrying out methodological studies; maintaining a census library; preserving maps and records; documenting census activities and keeping copies of all essential census information; promoting a continuing dialogue with stakeholders; updating the census frame for sampling and conducting intercensal demographic household surveys. Such activities also retain and improve the capacity of the census organization to conduct the census, and they help to create awareness of the availability and usefulness of census data. Census organizations can use the intercensal period to produce popular versions of official census reports to make census information more readily understood by the general public. The intercensal period is also an ideal time to investigate and test new technologies for interviewing, data capture, storage and dissemination. Unfortunately, financial constraints often limit the size and scope of intercensal activities.


12.              Evaluation of census results was the final topic addressed at the Census Symposium. Participants noted that evaluation and quality management should be an integral part of the census programme. They agreed that some kind of evaluation is necessary to identify problem areas and strengths in the census and that the credibility of the census is improved when evaluation results are shared with users. A number of evaluation methods have been developed, including comparing census results with administrative records, demographic analysis and the post-enumeration survey (PES). The PES is a valuable tool, but its results can be compromised if maps are inadequate; if the PES is not independent of the census operations; if probability sampling is not adhered to; and if the survey is poorly managed or executed. Many techniques for demographic analysis are also available, such as comparing data from successive censuses; examining census data for internal consistency; and using simple indexes of regularity in the age-sex distribution. 


13.              Both a PES and demographic analysis may be usefully employed if resources permit. In some countries, the PES is important because no other sources of data exist for comparison with the census. If a PES is to be conducted, and if it is to be successful, it is best conducted as soon as possible after census enumeration. It is important to maintain operational independence between the census and the PES, and the scope of the PES should be modest and manageable. Some participants felt that a country should not undertake a PES unless it could meet the methodological prerequisites.


14.              Censuses in the foreseeable future will continue to be the main source of demographic data, particularly for small-area data. The continuity of census programmes, however, is threatened by the rising costs due both to increases in population and to the amount of data collected. It is clear that detailed data on economic and social characteristics of the population could be more cost-effectively collected through regular household survey programmes. It is therefore recognized that census planners and managers would benefit from a serious reconsideration of which topics are essential for complete coverage on a small-area basis and which can be limited to a sample.


15.              The census is the most expensive data-collection exercise a country undertakes. However, the data are exploited only on a limited basis, because of delays in processing the results and the limited access to data by the public. Use may be limited also because many people don't know how to use census data or don't know how valuable they can be. One way of increasing use of census results is to get the public to be active stakeholders in the census enterprise. Modern technology has considerably improved the timeliness of data. In addition, publication of census results, together with metadata, is essential but infrequently accomplished. Metadata in this formulation is taken to include concepts, sample frames, editing procedures and assessment of census coverage and quality.


16.              Most census organizations have limited technical expertise for evaluating the census data quality. Many countries do conduct a PES, but seldom use the results for adjusting the data or indicating the level of coverage in the published volumes. Under the circumstances it is important that census organizations should bring in the technical expertise from outside to undertake the evaluation of census data. This will require not only sharing the information with outsiders but also trusting their judgement. A balance needs to be reached in this area to avoid unnecessary complications and unanticipated disputes.


17.              The emerging technologies have facilitated census taking. However, due to limited in-house expertise and poor documentation by the vendors, in appropriate languages, and, at times, adoption of technologies not fully developed, there is wastage of time and resources causing unnecessary delay in the publication of results. To avoid such problems, the Symposium participants emphasized that there is a need to produce technical guidelines and to organize training programmes that address these issues and equip statistical offices to make informed choices in selecting and implementing appropriate technologies.


A. Introduction

18.              The Symposium on Global Review of the 2000 Round of Population and Housing Censuses addressed the question: “When and under what circumstances do censuses succeed?” The Symposium addressed the issues and problems that emerged in the current census round (1995-2004) and discussed modalities countries have adopted to overcome some of the challenges faced by the countries in implementing the census programme. Some of these experiences may serve to guide census planning by countries that will conduct censuses during the next round (2005-2014).


19.              The Director of the United Nations Statistics Division (UNSD) introduced the purpose of the Symposium. He emphasized the importance of censuses in providing a snapshot of the population of a country, complete with its distribution and socio-economic characteristics. Censuses are the only data source that can provide small-area data, and censuses provide the basis for conducting intercensal surveys and activities.


20.              The Director of the Technical and Policy Division of the United Nations Population Fund (UNFPA) said she was pleased to cosponsor this symposium together with UNSD. She emphasized the need for proper and timely allocation of resources for census taking by both governments and international agencies. She recognized that, although countries have been able to absorb a much more substantial part of the census cost, the rising costs of census taking are putting very heavy burdens on countries’ limited resources. In this regard, UNFPA is organizing a seminar to discuss census costs to identify practical measures that can reduce these costs.


21.              In the Symposium, realizing that the population census was the main source of demographic and social statistics, the focus of the discussion was mainly on strategies to improve the census methodologies, including involving stakeholders in census activities, application of technologies, census-related activities during the intercensal period, census evaluation and demographic analysis. The application of new technologies in census activities from beginning to end was discussed. It was apparent that the application of technology varies considerably among countries and between developed and developing countries.

B. Strategies for involving stakeholders in census activities

22.              Population and housing censuses rely on a large and diverse group of stakeholders to fulfill the mission of informing citizens, businesses and governments about the benefits of the census. Many of these stakeholders are important census data users. Clearly, interest in census activities varies among stakeholders so that the census organization must categorize them according to their levels of interests. Stakeholder interests are also different at various stages of census activities. The involvement of census stakeholders in all aspects of census activity is crucial to ensuring a successful census that meets the needs of all data users. The key census stakeholders include government ministries and agencies, provincial, municipal and local governments, private-sector companies, secondary distributors, academics, libraries, non-government organizations, media and general public.


23.              The quality of census data is of major interest to stakeholders. It is therefore extremely important that statistical offices make every effort to involve stakeholders at all stages—from content determination to dissemination—to assure quality. Throughout the process it is important to continue to provide feedback to stakeholders on decisions made and the rationale for incorporating or not incorporating changes.


24.              Feedback gathered during consultation is then analysed and evaluated with internal partners in light of financial and operational constraints and other related considerations. Priorities are discussed, options are eliminated and viable alternative solutions are proposed. In order to facilitate consensus-building, major data users and stakeholders are regularly kept informed on the progress of the planning activities (content or dissemination) in various presentation forums. Thematic meetings regrouping stakeholders from different sectors have proven to be a very effective means of facilitating consensus as participants get a direct opportunity to expose and discuss their diverging views and underlying rationale.


25.              Ongoing consultation on data needs will ensure that relevant data are produced. Consultation and testing activities are essential to a user-oriented dissemination strategy, maximizing the accessibility and interpretability of census data. Consultation with stakeholders also gains support from respondents in collection activities.  Moreover, testing on the content of the questionnaire also contributes to the success of the census. Stakeholders’ involvement in the census is not only required to assess the socio-economic conditions in the country but is also a critical element in stimulating broad public debate on social issues, an essential element of democracy.


26.              Most statistical organizations established advisory committees to gather advice on topics such as demography, social conditions and health. Since many members of these advisory committees often come from the academic community, this forum has proven to be an effective means of getting feedback from this group. During the content determination stage, the census should also work closely with international organizations, to share professional expertise and to promote common concepts and practices to maximize the comparability of socio-economic data.


27.              Once it has been determined that the census is the best way to fulfill a specific data need, all potential new questions and changes to the questionnaire must be carefully tested with respondents before being adopted. The role of the national statistical office is to produce statistical information relevant to current and emerging needs of data users.  In order to reach the different groups of stakeholders, many different consultative mechanisms should be adopted.


28.              The Symposium focused on the value of involving stakeholders at every stage of census planning and implementation but noted that engaging stakeholders may raise problems as well. Sometimes stakeholders disagree with each other, and it is often not possible to forge a consensus. This may be particularly true when political issues are involved. While efforts to bring ownership of census operations to the stakeholders may bring positive results, the census organizations should also be very cautious in working closely with stakeholders that want to have a greater role in the census. For example, local governments and communities often want to have greater control in the recruitment of enumerators and management of census field operations.


29.              Any consultation process creates expectations regarding the amount of influence participants have in determining the content of the census questionnaire or defining the characteristics of a dissemination programme. Thus it becomes extremely important to set up a framework whereby stakeholders’ attention gets focused on specific points of discussion. This can be done during the consultation process or in the consultation guide provided to participants prior to the sessions.


30.              User expectations can also be managed by positioning the census in the context of the overall statistical programme as one means of fulfilling users’ needs. Such consultation activities will invite users to discuss all of their socio-economic data needs pertaining to census themes. This will maximize the full range of socio-economic data sources to meet users’ needs, instead of focusing on the census as the sole means of satisfying their current and future data needs. This should lower users’ expectations regarding the extent to which they can influence the content of one specific element of the statistical programme.


31.              Census data collection activities depend heavily on the willingness and cooperation of respondents. In order to make the public aware of the importance of participating in the census, it is essential to establish a public communications programme. This programme should emphasize the measures being adopted by the census organization to protect the privacy and confidentiality of the information provided. Many census stakeholders, including central and local governments, as well as other organizations, provide voluntary support to promote the census. The media also play a very important role in promoting the census to the public.


32.              The advice of stakeholders is essential in planning the dissemination strategy. This ensures that the dissemination strategy and the products and services suit the needs of data users. Some stakeholders also become critical partners in disseminating census data to ensure the widest possible use. When planning the components of the census products and services line and output media, the range of users’ abilities to access and use the information has to be taken into consideration because of the diversity of data users. Users should also be consulted on such other dissemination issues as user-friendliness of the products, searching and indexing features, pricing and licensing conditions and accessibility of the metadata (i.e., information about the data).


33.              Once the data are ready to be released, partnerships formed with numerous key sectors are vital to wider dissemination of census data. Public and private-sector organizations, libraries and the media are critical in ensuring broad dissemination. Dissemination partnerships should also be established with provincial and local statistical focal points. Partnerships with secondary and elementary schools as well as with school boards to encourage classroom use of census data will also be beneficial.


C.  Strategies for choosing among data collection methods

as sources of demographic and social statistics

34.              It is well known that there are three main sources of demographic and social statistics: censuses, household surveys and administrative records. These three data sources should complement each other as part of an integrated programme of statistical data collection which provides a comprehensive source of statistical information for policy formulation, development planning, administrative purposes, research and for commercial and other uses. It is essential that countries develop a national statistical data collection programme that determines which particular data sources are most appropriate for collecting certain statistics.


35.              A population and housing census is necessary to provide data to meet data users’ needs, provide a sampling frame and other population figures for household surveys, and also provide the base population needed in the computation of vital rates for data produced from a civil registration system. While population censuses are the ideal method of providing information on size, composition and small-area distribution of the population, including their demographic and socio-economic characteristics, population censuses are also the most extensive, complicated and expensive statistical operation for any country to undertake.


36.              The only alternative to conducting periodic population censuses is having a population register. However, for many countries, development of a population register is a long way off, since the prerequisite for developing such a register is having a complete civil registration system. Therefore, for the foreseeable future, in most developing countries, there is no substitute for continuing to conduct periodic population censuses.  Countries should also maintain a continuing programme of household surveys to obtain information that cannot be collected through censuses. In addition, efforts should be continued to improve the civil registration and other administrative records to fill the data gaps.


37.              To keep the census operation cost-effective, census organizations are usually under strong pressure to limit census questionnaires to the most basic items. Nevertheless, the topics to be covered in the census should be determined upon balanced consideration of (1) needs of data users in the country; (2) availability of information on the topics from other data sources; (3) national and international comparability; (4) willingness and ability of the public to give adequate information on the topics; and (5) available resources for conducting the census.


38.              Many countries carry out a sample enumeration in conjunction with the census to collect more detailed information on a separate questionnaire (long form). Collecting data on additional topics from a sample of population or households during the census operation is a cost-effective way to broaden and deepen the scope of the census and improve the quality of data collected.


39.              The household survey is the second main data source, and it is the most flexible of the three data sources. Many countries have instituted a continuing survey programme, which includes periodic surveys and ad hoc surveys to meet specific statistical data needs. Although ad hoc surveys may satisfy immediate purposes, they do not ordinarily provide a framework for a continuing database and time series. Continuing periodic surveys, on the other hand, are normally carried out to investigate a highly important phenomenon that needs to be monitored frequently. Other advantages of a continuing household survey programme include the opportunity for capacity-building and increasing the cost-effectiveness of the available resources.


40.              An adequate sample survey design is usually possible only with the availability of detailed population or household lists, enumeration area maps, and various control figures or other inputs which can be obtained only from a census. In this sense, the census is the major source for preparing a survey sample design.


41.              The third data source is administrative records. The statistics compiled from various administrative processes can be very valuable to the overall national statistical system. Many social statistics are produced as a by-product of these administrative processes. The reliability of the statistics depends upon the completeness of the administrative recording process and the reporting system. Unfortunately, in many developing countries, administrative records are not well developed. Administrative records are often limited in content and do not usually have the adaptability of household surveys or censuses from the standpoint of concepts or subject detail. While the administrative processes are continuing for the purposes of record keeping and administration, the compilation of statistics is secondary.


42.              One of the most important administrative records is a civil registration system. Civil registration is a major foundation for a legal system for establishing the rights and privileges of individuals in a country and the main source of vital statistics. However, in order that vital rates and other demographic indicators can be computed, it is necessary that population figures be available as a denominator, which normally can be provided only from censuses or complete registers.


43.              A reasonably complete civil registration system can further be developed into a population register system, which can provide demographic and social statistics of the population in a defined area. A population register system maintains central databases of every individual in the country that are continuously updated when there are changes in the characteristics of the individual. Countries that have established a central population registry (CPR) develop a unique personal identification number (PIN) for each individual.


44.              Development of a population register should not begin until the country achieves a reasonable completeness in the registration of births, deaths and other vital characteristics. In addition, developing a population register is not a short-term project. It requires a large investment and must be supported by the population at large, with established legislation, infrastructure and national budget. The use of the register for other purposes, including maintaining public security, will result in the lack of cooperation from the general population.

45.              Once such a system is established, the need to conduct the traditional decennial census becomes less important, since the country can carry out a register-based census. It is important to note, however, that only the information that is recorded in the register can be compiled and produced as a register-based census. The flexibility of asking about emerging issues is no longer available as in the case of a traditional census. Except for a few countries with relatively small populations, no developing country has a comprehensive population register system.

D. Funding for population and housing censuses

46.              Technical cooperation and assistance from multilateral agencies have played a major role in the success of past censuses. Given the limited budgets available and the limited capacity in many national statistical offices, there is a continuing need for such cooperation and assistance. New sources of funding will need to be tapped, including greater involvement of non-profit foundations and the private sector. Yet from both a supply and demand perspective, census data are largely a public good. So for the foreseeable future international technical and financial assistance for census taking will be required to complement national inputs.


47.              Developing countries are at different levels of statistical capability, and this is reflected in the quantity and quality of data they produce. Some countries lack financial resources and have limited human resource capacities, especially technical and managerial, compounded with institutional weaknesses. The high and growing cost of censuses, coupled with shrinking public-sector budgets in many developing countries, has posed a serious question about the future of censuses. Reduction in funding for international development assistance, which in the past has been a major source of funding for censuses, has exacerbated the situation.


48.              Several countries, especially in sub-Saharan Africa, have postponed their censuses, thereby increasing the interval of time since the previous census to more than 10 years. Other countries have secured funding at a very late stage in their census preparations, while others are experiencing funding gaps. Funding delays and uncertainty almost inevitably lead to delays in data processing and affect the range and quality of census results.


49.              Censuses need to be more cost-effective. The time is ripe to consider cost-saving strategies, including coordinating international census data requirements; sharing of experiences between countries; and sharing of selected census activities among groups of neighbouring countries with similar data needs. This might include having a common census year, absolute minimum core questionnaires, sharing of questionnaires, manuals, training, data processing, analysis and dissemination activities. It still requires considerable technical and financial support from the international community. UNFPA, in collaboration with UNSD and other partners, has supported a number of workshops to promote this strategy.


50.              Several countries stressed the importance of applying appropriate technologies as a way to make the census cost-effective, particularly in reducing the time to disseminate the census results. However, there are differing opinions as regards whether national census organizations should apply a cost-recovery policy in providing census results to data users. Some countries stated that cost recovery gives census organizations a bad reputation. Others suggested that cooperation with different line ministries (e.g., survey and mapping agency, government printing service, press and media organizations) might also help in reducing census costs.


51.              For more than three decades UNFPA has played a leadership role in supporting census programmes in developing and transition countries. However, with competing demands on its limited resources, coupled with reductions in core income over the past five years, supporting countries’ census-taking activities has become ever more difficult. Funding constraints have seriously affected the 2000 census round, especially in the least developed countries.


52.              UNFPA continues to play a pivotal role in helping to mobilize resources for censuses in most developing countries. Donors are conscious of the critical need for census data for many purposes and of the consequences of not having such data. Sometimes there is donor fatigue with the idea of having to support yet another census. The amounts requested from donors are often relatively large in relation to their budgets for particular countries. In many cases, requests to donors for support for their censuses are received late and the budget is overly ambitious.


53.              Developing countries need the requisite skills to negotiate with, and coordinate, a large number of donors. They also need to make an early start in trying to bridge the budget gap between what resources are available from the government and the estimated census costs. Moreover, donor guidelines on what they are prepared to fund can give rise to costing distortions and inefficiencies. Thus some donors will support the purchase of expensive technology but are not able to meet local costs of a census.


54.              In order to avert a funding crisis and ensure future stability, there is a need to systematically assess funding problems that have arisen in the current census round and to conduct research into census costs and operational methods to determine what practical measures can be taken to reduce costs. In addition, much effort needs to be made by line ministries (as stakeholders) to support the national statistical offices in making the case to the government for securing funding support for national censuses. International agencies who use national census data for a variety of purposes should also provide support for censuses.

E. Adapting new technologies to census operations

55.              In choosing the appropriate technology, census planners need to acquaint themselves with the state of the art, at both national and international levels. They should preferably travel to comparable countries that have recently used methods and technology that may be of interest. In deciding the parameters for a new census, one should look first at the preceding census. What worked well and what could be improved? If an approach was satisfactorily applied the last time, the arguments to replace it with something else need to be twice as strong.


56.              The conditions under which censuses are conducted differ greatly between countries. Technical awareness, a sense of the realistic, a methodical approach, and plenty of preparation time are the principal requirements for census planners. Census technology changes much more rapidly than the underlying statistical methods and principles. As new technologies are developed and become available, census managers must provide the balance needed in making difficult decisions between the commercially available off-the-shelf products, keeping in mind the proper role and function of census organizations. New technology should never endanger, and if possible should reinforce, the continuity of existing systems.


57.              In order to be successful, a new information technology (IT) project should be part of the wider process and related organizational changes rather than an end in itself. Census managers are in charge of the census process and should not be in charge of the development and implementation of wider IT projects. This is a focus that often gets lost as a large IT project develops. When considering the technological options before them, census offices face a number of questions, including how to make an informed choice in selecting appropriate technology; how to maintain the integrity of the existing statistical and census systems; how to deal with the option of outsourcing and management of outsourced tasks; and how to deal with confidentiality concerns.


58.              Even for countries that have a solid technology management process in place, it is still a challenge to choose appropriate technologies to lead to a successful census project.  Generally, it is best to avoid application of new or “immature” technologies, because new and emerging technologies are notoriously difficult to assess in terms of when, or if, they will mature and become mainstream products. Learning from the experience of other countries that have adapted the technology for similar applications and comparing their results can be very helpful. Carefully inspecting the adaptations necessary to operate in another environment can make the difference between success and failure during implementation.


59.              A population and housing census differs in many respects from day-to-day statistical work. It may be necessary to recruit professional management, experienced in dealing with large but temporary organizations. A census operation requires efficient communication between thousands of persons, as well as procurement and storage of a large variety of items, most of which have to be distributed to all parts of the country, and then recollected. Recent developments in mobile telephone technology (cellular phones) have made person-to-person communication easier, even in countries with extensive and reliable fixed-line networks. But complete mobile coverage has not been accomplished in most developing countries.


60.              Improved computer software and wide availability of personal computers (PCs) have made managing the movement of goods much easier. Bar-coding is the most common example of automated information collection and tracking technology. Using bar codes instead of printed numbers has advantages in avoiding transcription errors and speeding up processing. At the point where the materials are sent out, the codes will be scanned, allowing automatic update of a database of items forwarded. The same process can be used to maintain a database of items retrieved from the field.


61.              The current census round has seen the breakthrough of intelligent character recognition (ICR) technology. Nearly all developed and many developing countries are applying imaging technology through scanners and recognition software for their censuses in the 2000 round. ICR offers a promise of greater efficiency but requires elaborate pre-testing before using it. The fundamental problem is still recognizing the poor hand-written characters, which have made some countries limit the automatic recognition to marks or numeric digits only.


62.              Experiences from countries using this technology show that the ICR process does not always work as smoothly as anticipated. At a recent meeting among countries in the ESCAP (UN Economic and Social Commission for Asia and the Pacific) region, some countries reported problems of varying degrees in their data capture using this technology. The Symposium agreed that despite the problems encountered, scanning technology has helped in speeding the census process. The application of ICR in censuses has certainly not become an off-the-shelf technology; rather it requires careful design and extensive pre-testing. The Symposium concluded that ICR technology is still not a mature field and is due to change significantly over the next five to ten years.  Census managers should carefully scrutinize proposals for new applications of this technology over the next several years.


63.              Census data entry is a potential candidate for outsourcing, since it is a one-time high-volume application. In outsourcing the ICR application, it may be advantageous to contract only one company to print the questionnaires and capture the information to avoid ambiguity of responsibility if scanning problems occur. It should be noted that outsourcing brings responsibilities of contracting and monitoring that also require resources. Quality assurance, which is a major consideration in any census, becomes even more crucial if outside contractors are involved. Controlling outsourced work requires different kinds of skills for census managers. In a census operation, one may end up in a situation where the contractor is in control, since the census organization, even though unhappy with the services provided, cannot afford to turn away. The better approach will be to make the outsourced company understand the mutual benefits they will obtain if the project succeeds.


64.              Whereas in the previous census round the use of the Internet for data collection was still unusual, attention has recently been focused on the Internet as a gateway into an increasing number of homes. Using “push” technology, it is possible to deliver a uniquely identified electronic questionnaire to each Internet-connected household, possibly already pre-filled with basic data obtained from the civil register. Several problems that hold back electronic data collection from households include authenticity; incomplete coverage; bias (Internet access is more common in affluent and younger households); unstructured address system; fraud; and security of the information. 


65.              Despite these difficulties, several countries, including Switzerland, the United States of America and Singapore, have allowed electronic responses during the 2000 round of censuses. Since it is unlikely that printed questionnaires could be abandoned soon, census data collection via the Internet requires seamless integration of the two data streams. Several participants raised the use of hand-held computer devices as new and promising technology that needs to be further investigated for the next round of censuses.


66.              While printed publications remain important, online dissemination via the Internet has become more and more in demand. The capability of a statistical organization’s web site is becoming even more important. Statistical and census organizations nowadays are not only assessed on the quality and timeliness of the printed information, but also on the effectiveness of their web presence. While data users expect statistical organizations to make full use of new media, there continues to be a substantial demand for paper publications. One of the dangers of this increase in efficiency is to lose the quality control and coherence brought by more careful management that was established in the old publication process.


67.              Information dissemination on non-rewritable high-capacity media also remains an important delivery channel, especially for massive data that are not highly time-sensitive, such as most census information. Censuses nowadays routinely result in the production of many CDs, and the first DVD (digital video disk) products of much higher capacity have appeared.


68.              There have been concerns with the privacy of microdata and the potential inference of private information from direct electronic access to census information. A delicate balance must therefore be established between the ability to provide detailed electronic information products, which can be analysed and correlated with other diverse information, and at the same time to provide adequate protection for the privacy and security of the raw data sources.

F. Identifying and resolving problems of census mapping

69.              For the 2000 round of population and housing censuses, most statistical offices have had the strategic advantage of an accumulated knowledge base as well as maps and materials inherited from the past censuses. During the past decade, the scope and methodologies of census mapping have also been greatly affected by rapid advancements made in Geographic Information System (GIS), digital remote sensing and Global Positioning System (GPS). However, implementation of cartographic activities for the current census round has been fraught with numerous challenges and problems.


70.              Viable and self-contained cartographic units and services have been established in most countries. But in several countries these units are still not maintained on a continuous basis. In a few countries these units even become practically non-existent after the census enumeration. Factors that seem to have adversely affected the sustainability and technical capacities of cartographic units are the high staff turnover, further depletion of technical capacities, and non-availability of adequately qualified personnel to fill positions. Countries should take remedial measures and strategies to sustain cartographic units and redress staff inadequacies by the formulation of a comprehensive cartography programme right at the outset. A cartographic component should be included in the budget, and a work programme for individual sample surveys and other intercensal data-collection activities should be established.


71.              Availability of appropriate base map and resource materials at affordable costs is also crucial to successful implementation of the census-mapping programme. Lack of appropriate base maps still poses a serious constraint in developing countries, mainly because the available maps are outdated and lack coverage on adequate scales. They are often either out of stock or available in limited quantities and contain parameters that are not fully matched with those adopted in the new technologies (GIS and GPS). To rectify these deficiencies, countries have to carry out intensive field-mapping exercises consuming a considerable amount of resources and time. Some countries adopted good practices by formulating cost-effective and area-specific strategies of field mapping based on the assessment of gaps and deficiencies in available base maps.


72.              In many developing countries, implementation of pre-census cartographic activities, including the production of enumeration maps, has often experienced delays, due to the unrealistic assessment of time, manpower and resources required, as well as because of lack of support from local administration. To avoid such delay, it is necessary that countries carry out a thorough assessment of the field-mapping requirements, closely monitor the progress rates and motivate field staff to work according to plan. 


73.              To meet the operational requirements of household surveys, a national master sampling frame should be developed based on a correct census frame and reliable population estimates from the census final totals.  The enumeration area (EA) frame should be developed to be comparable with the past census frame, capable of producing data for smaller areas, flexible to produce data for various systems of administrative and statistical areas, suitable for sample surveys and other data-collection activities, and compatible with GIS development requirements. The census frame also needs to be harmonized with other systems of social and political subdivisions by establishing realistic and commonly used place names with the help of local administration.


74.              Automated mapping has been adopted by many statistical offices since the previous census rounds but, in many countries, its applications were limited to production of publication of maps and production of enumeration maps using computerized mapping systems. The value of census information is enhanced if it is combined with the underlying base maps, which permit users to generate thematic maps of their choice.


75.              With rapid advancements in digital mapping and GIS, many countries have embarked on the development of comprehensive GIS applications. In many countries, this development has been made possible because of the involvement of multiple national stakeholders supplemented with external assistance. Electronic maps have become indispensable and cost-effective tools for a wide range of operations in censuses and statistics. The main problems encountered in developing GIS to produce census enumeration maps are the lack of up-to-date base maps, lack of trained staff and the high cost.  Other problems are coping with the large volumes of data needed to depict geographic information and choosing effective storage and data manipulation formats and standards.  The industry is still changing algorithms and technologies for storing and manipulating large-scale GIS data.


76.              The use of GIS technology for producing census enumeration maps should be planned with sufficient lead time, involving other national stakeholders and potential GIS data users. In addition, application of GIS has created a new dilemma for census managers since it has widened the scope of census work itself. Statistical and census organizations need to decide how much work in correlating base map information, physical structures, road networks, and the like are appropriate for a statistical/census organization, and how much should be left to others. It is important to note that the development of GIS is a long-term process and therefore should be implemented in a progressive manner.


77.              Outsourcing of census mapping/GIS projects has not become a common practice, especially in developing countries, due to inadequacy of resources and non-availability of competent private GIS companies. Experiences have shown that implementing a GIS project jointly with the private contractors has not been as smooth as conceived initially. It is necessary to verify thoroughly the track record of the company, particularly from the clients who have received services in the past. The contract should clearly indicate the precise specifications of the final outputs, including explicit deadlines. In addition, issues relating to copyright and ownership of data must be clearly spelled out in the contract.

G. Maintaining census-related activities

during the intercensal years

78.              Census-related activities during the intercensal years provide a smooth transition from one census to another and optimize data utilization. They serve as an important link between the censuses. They need as much attention and careful planning by census management as the main census itself. Above all, they help retain and improve national capacity built at a great cost, in some cases with external technical assistance.


79.              Activities during the intercensal years lend continuity to census operations and contribute towards an effective and efficient programme for the next census. The main activities during these years include (1) provision of services to data users; (2) continuous updating of administrative boundary changes as advance preparation for the next census; (3) carrying out methodological studies; (4) maintaining a census library containing census publications and electronic products; (5) preservation of essential maps and records; (6) documenting census activities in administrative reports and retaining multiple copies of all essential census instructions, circulars and questionnaires for reference and guidance in the next census; (7) continuously updating digitized maps for use in the next census; and (8) updating the census frame for the purpose of sampling.


80.              The Symposium agreed that in every country there is a need for a permanent census office, usually within the national statistical organization, even if it is on a modest scale. This will go a long way towards maintaining institutional memory and archiving of census activities after the main census project is over. It is true that some countries may not be able to afford a census office on a continuous basis; however, at least a nucleus office should be maintained retaining essential professional/technical staff and equipment procured for the census. The absence of a continuous census office may also result in underutilization of census data.


81.              The rapid build-up of staff prior to a census and reduction of staff following fieldwork and data processing are management challenges. These personnel shifts also provide useful opportunities to management, however. Promising staff members may be given promotions or more responsibility. Staff members may be rotated so that they gain experience in a number of census functions. Field staff may be given assignments in the central office. More time is available for long-term training of census staff members.


82.              Clearly, intercensal functions will be more valuable and effective if adequate human and financial resources are allocated to them.  In this connection, it is important for the census office to maintain continuing dialogue and cooperation with data users so that a demand for census data and services exists.


83.              A data users’ service centre should form an integral part of the census office during the intercensal period. Its staff may have to deal with a wide range of customers—ministries and government departments, universities, banks, large companies, and individuals like members of Parliament, researchers and students. The census office may develop small-area databases or intranet services to make census data available to other government departments. For example, census data have proved valuable for disaster management. A census office library has to be maintained to hold all published reports and census electronic products. It is also necessary for the staff to ensure that census publications are available in leading libraries (including state/provincial libraries).


84.              There is a need to develop a comprehensive post-census communication strategy. The census office needs to perform many functions to continue to serve stakeholders during the intercensal period.  It may need to reprint publications, produce more copies of CD-ROMs and maintain the Internet site for census data. Apart from the publication of general census reports, tables and research monographs on particular topics, simpler and more target-oriented reports or illustrated folders should be brought out during the intercensal period. Popular versions of census reports would make census results more easily understood by the average citizen.


85.              During the intercensal period, the census office may carry out analytical studies, perhaps in collaboration with research institutes and other concerned agencies. Census offices should maintain research and analysis units.  The census office will normally wish to carry out methodological studies of various census procedures or on particular census questions, concepts or definitions. This period is also an ideal time to investigate and test new technologies for interviewing and for data capture, storage and dissemination.


86.              During the intercensal period maps have to be not only maintained but also updated. It is necessary to monitor boundary changes made by the government from time to time so as to effect the changes in the maps and records for use in the next census. As far as possible, countries should digitize all census maps so that changes in the boundaries of Districts/Communes/Villages/EAs can be updated more efficiently. If this is not done during the intercensal period, it may give rise to administrative problems, delays and omission of areas.


87.              Once GIS has been developed with census data integrated into it, continuous updating of GIS databases is a must whenever new information is available. During the intercensal period, it is also necessary to update GIS with information from other sources of data. Updating the GIS is possible only with coordination and cooperation among the different data-collecting agencies. The staff should verify the accuracy of the incoming data before entering them into the system. Missing information has to be imputed with care in consultation with the agency concerned.


88.              The intercensal period should also be used to complete full documentation of the census, including of the electronic systems, of planning and evaluation activities and of computer programme specifications. The census data and metadata (information about the census data) need to be archived for long-term storage and retrieval. As technology for data storage changes rapidly, it is usually necessary to maintain microdata from earlier censuses in forms that will permit continued retrieval. Tapes from mainframe computers deteriorate over time and the data need to be transferred to other storage devices. The Intergrated Public Use Microsample (IPUMS) project can provide funding and technical assistance to census offices for the purposes of maintaining microdata and metadata from earlier censuses.


89.              Generally an administrative report is written after the census by the project management. It incorporates the census methodology and should contain such information as how concepts were developed, procedures adopted to enumerate the population, staffing pattern and organizational problems that cropped up and how they were solved. In addition to the administrative report, it is necessary to keep copies all of important internal circulars containing instructions, specimen forms prescribed to monitor and control the census, publicity material and important correspondence with field agencies. All these will serve as useful reference material in the successive censuses. For permanent reference, it would be desirable to store the administrative report and the documents mentioned in CD-ROM or similar media.

H. Census data evaluation

90.              It is generally agreed that census results should be evaluated and that census evaluation should be an integral part of the census programme. Owing to the massive nature and complexity of the census operations it is inevitable that some inaccuracies arise, including coverage and content errors.


91.              A number of methods of evaluating censuses have been developed and used by countries. Such methods include demographic analysis, comparing census totals with figures from other sources and the post-enumeration survey (PES). Some of these methods can be used as a complementary source or independently. The choice of which method to use depends on the country’s preferences and feasibility of the method in terms of data availability and resource and methodological requirements.


92.              The Symposium agreed that both a PES and demographic analysis were valuable tools for assessing the quality of a census. Both should be applied to the extent that resources permit. Such evaluation or analysis is important for the census organization to identify problem areas or strengths in the census. The census organization can also increase the credibility of census results by making available to users the findings of the PES and demographic analysis.


1. Post-enumeration surveys


93.              The PES is a method commonly used by many countries for census evaluation. In a PES, an independent and relatively small sample of households is selected. The census and survey results are then matched to measure the coverage and/or content errors in the census. There is an assumption that the survey operations are more fine-tuned compared with the census. The PES operation normally involves sample design, listing, interviewing, matching, in some cases field reconciliation and estimation.


94.              PES results have a number of uses. For example, countries have used the results to uncover defective methodologies or operations, to adjust census results and to evaluate area frames. Many participants at the Symposium felt that a PES was an important tool in the evaluation of census results. Suggestions were therefore made that it should be considered as an integral component of the census and that a handbook should be prepared on the subject. 


95.              It was, however, stated that census results should be subjected to evaluation methods in addition to the PES. Others argued that with adequate quality assurance measures taken during the census, it was not necessary to carry out a PES in view of resource constraints and failure of such surveys, mostly in developing countries, in the past.


96.              While a PES can be a valuable tool for evaluating census results, its usefulness can be compromised if one or more of the following problems exist: poor cartographic work; lack of operational independence between the PES and the census; failure to adhere to probability sampling; and poor management and execution of the survey.


97.              In the discussions which ensued, participants, in addition, alluded to some problems associated with the PES, such as difficulties in matching; lack of qualified staff both to design and execute the PES; hurdles of carrying out the PES to capture special populations such as nomads; practical difficulties of maintaining independence between census and PES operations; response burden (because the survey is usually carried out immediately after the census) and problems of sampling errors.


98.              For a PES, therefore, to serve its useful purpose, it must be carefully planned and carried out within the operational and statistical constraints. The following were some of the suggested steps to be taken in order to make PES results meaningful as a tool of census evaluation: developing good area and household listing frames; designing good probability samples; maintaining, to the extent possible, independence between the PES and the census; harmonizing definitions and concepts used in both the census and the PES; using qualified and well-trained staff for the PES; keeping the operation as simple as possible and allocating adequate funds for the survey as part of  the census strategic plan.


99.              The Symposium agreed that in most cases PES results should not be used to adjust census data, but should be made available to users to assist them in interpreting and utilizing the data. If analysts are confident in the PES results, they could be used to adjust the base population in making population projections, as has been done in several countries.

2. Demographic analysis


100.          Census results should also be evaluated by demographic analysis. A wide range of methods of demographic analysis has been developed. The age-sex pyramid may be examined for regularities or anomalies. Many simple indexes of regularity in the age-sex distribution have also been developed. Many methods of estimation require the use of stable population techniques, but few national populations currently have constant fertility or mortality levels.


101.          Much can be learned about the quality of the census by comparing its results with data from previous censuses or from such other sources as vital registration, civil registration, population surveys or administrative records. Two censuses may be compared by examining intercensal cohort survival, for example. The data from a single census can be examined for internal consistency.


102.          Several computer packages exist for such demographic analysis, but it is important that experienced demographers apply them in collaboration with persons knowledgeable about the history and culture of the population concerned. Careless application of computer programs for demographic analysis can lead to erroneous conclusions. In some developing countries, adequate analytical expertise is not available in the national statistical office. UNFPA/CST’s and the United Nations regional commissions can provide such expertise if the statistical offices have staff members with sufficient training to be able to absorb such technical assistance.


103.          It is especially important that thorough analysis of census data be carried out before they are used for population projections. Particular attention should be paid to the age group 0-4 years and to recent levels of fertility (and these two indicators should be consistent with each other, when taking into account infant and child mortality). The population aged 0-4 and recent fertility rates are critical data for education and health planning, and errors in their measurement would greatly reduce the utility of census data.