Symposium 2001/34

13 July 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












Statement from Islamic Republic of Iran *

Abbas-Ali Zali **



A. Introduction. 2

B. Strategies for involving stakeholders in census activities. 2

D. Adapting new technologies to census operations. 4

E. Maintaining census-related activities during the intercensal years. 5

F. Identifying and resolving problems of census mapping. 5

G. Post-enumeration surveys: are they worth it or not?. 6


A. Introduction


1.                  The fifth census of the Iranian decennial national census of population and housing took place from 23 October to 16 November 1996. Compared with the previous ones, the 1996 census enjoyed some advantages, as follows:


1.      To enrich the national database, the identity card number and serial number were included among the items of the census questionnaire;

2.      To complete the allocation of 10-digit postal codes in cities, towns and villages, and to expedite the assigning of the national identity number to all nationals, the place-based listing forms of the post office were used in the census;

3.      To give equal training to everybody involved, an educational video cassette was prepared to teach the forms and instructions;

4.      To capture data from the filled-out questionnaires, the optical mark reader (OMR) method was used for the first time, which expedited the job;

5.      The census results were disseminated as printed materials and on CDs just six months after the field stage;

6.      The latest version of the International Standard Classification of Occupations ( ISCO-88 ) was used for the first time;

7.      Also, the imputation method was applied for some non-response data, which contributed to an early data dissemination. The reasonable relationships between different items of the questionnaire were determined and errors were diagnosed; then the incorrect data were replaced with the correct data, which was obtained after considering indices and expected logical relations.


B. Strategies for involving stakeholders in census activities


2.                  In the Islamic Republic of Iran, the Statistical Centre of Iran is by law responsible for implementation of the censuses. Every census is launched by the President’s decree. Since there is not a permanent and continuously working organization for carrying out the censuses, a headquarters is established consisting of a group of managers and senior experts from the Statistical Centre of Iran (SCI) and the representatives of the interested organizations for each census. The people gathered are then arranged in different groups and committees. The headquarters of the 1996 census was formed in the fall of 1994, two years prior to the field operation, and began work by discussing the census objectives, reviewing former censuses and recognizing the statistical topics. As the discussions began, the significance of considering the data users’ notions in all stages of the job, particularly in deciding on the census content—the topics and concepts and definitions—was deeply felt.


Accordingly the following organizations were called on:

        ·          Nomads Affairs Organization    

        ·          Islamic Republic of Iran Broadcasting

        ·          State Welfare Organization

        ·          Central Bank of Iran

        ·          Tehran City Hall

        ·          Ministry of Labour and Social Affairs

        ·          Ministry of Education

        ·          Ministry of Health

        ·          Social Security Organization

        ·          Ministry of Culture and Higher Education

        ·          Ministry of Housing and Urban Development

        ·          Plan and Budget Organization

        ·          Ministry of the Interior

        ·          Ministry of Jahad-e-Sazandegi

        ·          Plan and Budget Organizations of Ostans ( provinces)

        ·          Ministry of Cooperatives


C. Strategies for choosing among data-collection methods  as sources of demographic and social statistics


3.                  Proposals presented by the organizations and persons answering the call mostly included their intended items and, in some cases, presentation and modification of definitions and concepts as well as frames of results and tables. Altogether, 110 proposals were offered on the census items. In the first step, these items were classified at headquarters into three categories: general use, special use and non-statistical use.


4.                  The first two categories were compiled from three methods: census, registers and sample surveys. Investigation, classification and finally selection of the proposed topics were made according to the following criteria.


·                    Recognition of  main characteristics of the population, household and housing within the national boundaries so as to fill the existing statistical gaps as well as meet the current statistical needs for policy and decision making;

·                    Necessity of response to national priorities and fulfilment of the development plan needs for general information as well as information on specific groups of the population;

·                    Capability of representing results and comparing them at any geographical level and on the general and basic items with the results obtained from the previous censuses;

·                    Giving priority to the basic information;

·                    Achievement of international and regional comparability while giving full consideration to national needs; and

·                    Enjoying practical efficiency and reasonable costs during the implementation of census plans.


5.                  Moreover, other factors had to be taken into account, such as determination of the priorities of the census items, volume of the job, and administrative and operational limitations of the census, as well as the nature of the census, involving a large number of enumerators with average skills and capabilities.


6.                  It was necessary to prepare a plan while considering all of the above-mentioned principles and criteria. Several seminars and meetings were held at census headquarters with related groups and committees. Also present were representatives of the concerned organizations, researchers and lecturers at the universities. Each of the new statistical items was evaluated according to the intended criteria. During the meetings, discussions were held on preparation of definitions and concepts, needed classifications for some topics and items confirmed to be included in the census. Also discussed in collaboration with the concerned organizations was the process of presentation and dissemination of the census results. It was not necessary to persuade the concerned institutions of the reasons that some of their requested topics were not included in the census.


7.                  In general, the primary aim of the population and housing census in every country is to meet national needs in the area of specific demographic and housing characteristics. In some instances, when there is a discrepancy between national needs and international recommendations, the national needs should be given priority.


8.                  Additionally, in these meetings, international advisors and overseas university professors were consulted. Census plans available in some other countries—including Australia, Canada, China, France, India, Japan, Malaysia, Pakistan and the United States—were investigated.


1. Topics considered for the 1996 census


9.                  Some items discussed in these meetings, and the reasons for acceptance or rejection of them in the 1996 population and housing census are presented below.


a. Cause of migration


10.              This topic was not included in the census agenda for the following reasons, but it was to be included in the sample surveys:

·                    Cause of migration does not play a significant role in the population projections;

·                    Cause of migration can change over time; therefore, it lacks stability;

·                    In some instances, more than one factor is involved in the cause of migration; thus, it is difficult to determine the main reason for migration.


b. Information on fertility and mortality


11.              Collection of information on fertility and mortality is a time-consuming job and requires well-trained enumerators. Therefore, such data were to be collected in the sample surveys. After the end of census taking, a sample survey and a post-enumeration survey were immediately executed concurrently.


c. Enumeration of building instead of place of residence


12.              This topic was not approved owing to the complexity of the building definition and the additional burden on the enumerators.


d. Means of commuting


13.              This topic was first approved and included in the pilot census questionnaire. However, considering the pilot results obtained, and the fact that the traffic problems exist only in some large cities, inclusion of this topic in the main census questionnaire involving all areas of the nation was not cost-effective.


e. Mobile nomadic households


14.              The topic of mobile nomadic households and how to satisfy their needs covers only a small part of the country. Therefore, it should be investigated in the sample surveys. In the 1996 population and housing census, only basic questions were included in the questionnaire.


f. Radio and television coverage in villages


15.              Because of the needs of the Islamic Republic of Iran Broadcasting for this kind of information and lack of access to this information through other methods, questions on radio and television coverage were included in the 1996 census questionnaire.


g. Cause and type of physical and mental disabilities


16.              Considering the needs of the State Welfare Organization for basic information, and international recommendations in this regard, the question on households with disabled persons was discussed. After much consideration, this topic was approved, but questions on the cause of the disability and other details were left for sample studies.


17.              After summing up the main results of the comments, and development of the preparatory census plan in the autumn of 1995 (that is, a year following the formation of the census headquarters, and a year prior to the 1996 population and housing census), the primary census plan was tested.


18.              It is necessary to mention that when the census plan was being developed in the headquarters over a two-year period, some ad hoc tests were employed on some items in addition to the above test, and the probable inclusion of them in the questionnaire was discussed. The results obtained were very useful in the final development of the census plan.


19.              After conducting several tests and evaluating the results, discussions were held with the representatives of organizations, executive bodies of provinces, professors of the universities and researchers in different seminars and meetings. Following these discussions, the final selection of topics and finalization of the census plan began.


D. Adapting new technologies to census operations


20.              In general, there are many problems in collecting information, among them the speed of collecting information and the accuracy of the data collected. By developing new technology, traditional methods are being abolished and new methods are being applied to census operations. Completing paper questionnaires is a very time-consuming operation owing to the question-and-answer process and investigation of incorrect data.


21.              Because of the high volume of data in censuses, it might be impossible to employ the above-cited methods. Making the society aware of the importance of answering questionnaires is an issue which has been taken into account by advanced countries for many years. Results obtained have been successful. Therefore, the data collection is carried out without the aid of the interviewer in the censuses of such countries. However, what is important is the stage following completing the questionnaires—that is, what kind of methods are employed for data capture. They include traditional (keyboard) data entry, optical mark reading (OMR) and optical character recognition (OCR), depending on the type of the enumeration and the expenditure. Unfortunately, OCR is not commonly used in countries such as the Islamic Republic of Iran due to the local languages. However, despite the problems existing in the employment of OMR, the use of this method in the 1996 census decreased the data dissemination period, for the first time, to less than six months since the implementation of the census.


22.              In the traditional (keyboard) data-entry method, ready-made packages are used for designing questionnaires. However, the use of the packages in some questionnaires is impossible for certain reasons. Therefore, programming is called for.


1. Data processing


23.              After collection of data, it is necessary to edit, correct and process data generated in the census. The traditional method commonly uses conventional files. After collection and sorting of data in the cited files, the collected data are investigated. This is carried out through traditional programming and using ready-made packages. The data-capture operation is the next stage, and this is done by using traditional programming or software packages such as Integrated Microcomputer Processing System (IMPS).


E. Maintaining census-related activities during the intercensal years


24.              As mentioned before, the SCI usually establishes a provisional preparatory headquarters two years before the census. It comprises the experienced experts of the Centre who are responsible for the planning and administration of the census. The headquarters, by taking advantage of its different groups and committees, manages the pre-census and post-census activities, as well as the actual census.


25.              These activities consist of selection of topics, questionnaire preparation, cartographic work, planning for training and control, census publicity, staff recruitment, budgeting, and the like for pre-census training; fieldwork, control, and report on the progress of the work during the census; and finally the post-enumeration survey, preliminary review of the results, data entry and data processing, data capture, tabulation and dissemination after the census. Along with the above activities and as a part of them, a committee is organized for documentation and recording. Its main responsibility is to collect and classify all the documents related to various stages of the census and store them for future utilization by the Centre experts and other users.


26.              After the end of the census, the documentation group as well as other census divisions will be dissolved and its members will return to their previous duties in the Centre.  All documents prepared by the group are kept in the library of the Centre. Census information is released after the data processing as publications in various geographical regions for public use.


27.              After the completion of the census by the headquarters and its related groups and committees, all the related activities concerning the census, such as ad hoc studies using census information, are performed through the departments of the Statistical Centre of Iran which are concerned with socio-economic statistics.


F. Identifying and resolving problems of census mapping


28.              Major problems emerged in the mapping operations for the Iranian 1996 census, as described below:


·                    The first problem concerned base maps. Although the Statistical Centre of Iran is not legally in charge of developing maps at the national level, due to the difficulties and inefficiencies concerned with developing the base maps, the Centre is forced to produce, correct and update the maps required for implementation of censuses and surveys. In each case, however, some of the maps are provided by the National Cartography Centre, and the Statistical Centre merely adapts them to the project’s framework.

·                    There was a lack of adequate facilities, technical and financial support and expertise needed for developing the maps and updating them at different stages of surveys and censuses.

·                    The mapping project was unable to attracting professionals at the national and subnational levels because of recruitment restrictions.

·                    The lack of permanent geographic units resulted in the inability to compare collections of statistical data in different time series. In the 1996 census, delays were encountered in determining enumeration districts.

·                    Frequent changes in administrative divisions caused some problems and imposed a heavy burden on updating the maps accordingly.

·                    There is no accurate base map for developing a Geographic Information System (GIS), which could greatly contribute to the removal of problems concerned with updating and making use of maps in censuses and other statistical projects.

·                    Finally, map-related problems emerged in the operations stage, which were caused by inefficient updating of the maps and inadequate training of the enumerators. These difficulties, in turn, originated from the above-mentioned problems.


29.              Since the completion of the 1996 census, the Statistical Centre of Iran has been seeking strategies to overcome the problems encountered during the census, the most noteworthy of which is providing the preliminaries for development of a GIS. The project started six years ago and the progress is satisfactory with regard to the financial and technical potentials. One step taken is digitization of all rural maps in scales of 1:50,000 and 1:100,000.


30.              The mapping staff in the SCI are working hard to resolve all the problems they experienced in the last census and to get ready for the next one.


G. Post-enumeration surveys: are they worth it or not?


31.              In the 1996 population and housing census, a post-enumeration survey was conducted. It aimed at estimating underenumeration of population in terms of different factors, such as lack of complete coverage of places and household members. The results of the post-enumeration survey were not used for adjustment of the census results. However, analysis of the PES results helped to diagnose the factors contributing to the undercount, so as to prevent them from affecting the 2006 census. It should be noted that the following changes were made in the 1996 census compared with the previous ones:


·                    Decrease in the number of lines of the household questionnaire;

·                    Increase in the number of pages of the questionnaire (from one to two);

·                    Inclusion of the identity card number and serial number in the items of the census questionnaire; and

·                    Household lists existing in the post office of the Islamic Republic of Iran were used in most urban areas.


32.              Some of these changes increased the undercount of the population. Moreover, the undercount in urban and rural areas as well as in different areas varied. It seems that the analysis of the PES results may decrease the undercount of the population in the 2006 census. We hope that the post-enumeration survey plan is designed so that the results of the census could be adjusted.





*       This document was reproduced without formal editing.

**     Statistical Centre of Iran, Islamic Republic of Iran. The views expressed in the paper are those of the author and do       not imply the expression of any opinion on the part of the United Nations Secretariat.