RECOMMENDATIONS FOR THE 2000 CENSUSES OF POPULATION AND HOUSING IN THE ECE REGION

1.  The recommendations for the year 2000 round of population and housing censuses in the ECE region set out in this document were drawn up at joint ECE/Eurostat meetings on population and housing censuses convened over the 1995-96 period under the programmes of work of the Conference of European Statisticians, the Committee on Human Settlements of the Economic Commission for Europe and Eurostat.  The conclusions reached by these meetings concerning the contents of the '2000' recommendations for the ECE region were endorsed by the Conference of European Statisticians at its forty-fifth plenary session in June 1997 and by the Committee on Human Settlements at its fifty-eighth session in September 1997.  The Conference also authorized the publication of the recommendations in its Statistical Standards and Studies series jointly with Eurostat.  The recommendations were also approved by Eurostat for use as a guide by the EU countries.

2. The aims and objectives of the Recommendations are I) to provide guidance and assistance to ECE Member States and other interested countries in planning the content of their census; and ii) to facilitate and improve international comparability through the harmonisation of data, definitions and classification of topics. Some countries may also wish to consult the World Recommendations^1/() when planning the content and tabulations of their census. The Recommendations are also useful for assisting EU countries in providing various types of data that Eurostat needs. ^2/()

3. The recommendations for the ECE region were developed within the framework of the 2000 World Population and Housing Census Programme, pursuant to resolution 1995/7 adopted by the Economic and Social Council of the United Nations on 19 July 1995.  In the operative paragraphs of this resolution the Council:

4. Censuses covering the total population and housing are indispensable for providing statistical information on the population, labour force and housing situation on a uniform basis for small areas and sub-groups of the population.  Registers and other administrative sources are an alternative to the traditional census as far as they contain the relevant topics, definitions and classifications and cover the entire population. Sample surveys used alone cannot provide equivalent data but they can be used in combination with a census or to supplement census information on specific topics.

5. The scope of the ECE/Eurostat joint recommendations is limited to the following three elements: (a) a list of "core" topics which countries should cover in their censuses, and recommended definitions and classifications for each of the core topics; (b) a list of "non-core" topics which countries may wish to consider including in their censuses, and suggested definitions and/or classifications for some of the non-core topics and 8 a recommended basic tabulation programme, with illustrative sketches of the scope and contents of the recommended tabulations.  The ECE recommendations do not cover in detail such questions as the definition and essential features of a census; the planning, organization and administration of a census; or the use of sampling in a census.  The World Recommendations ^1/() cover these issues more fully.

6. There are three ways of collecting census data, namely:

7. The present recommendations are intended to apply to all countries, whichever method of data collection is to be used.  The selected method - traditional or register based - should take into account a wide range of issues such as (a) the users' needs, (b) the quality of the data, 8 completeness of the count, (d) data protection and security, (e) comparability of the results between the countries and over time, (f) the burden on the respondents, (g) timeliness of outputs and (h) financial and political implications.

8. Censuses covering the total population and housing stock are indispensable for providing statistics on the population, family, household and housing situation on a uniform basis for small areas and sub-groups.  The characteristics of the population include geographic, demographic, economic, educational and household and family characteristics.  For many countries, a traditional census is vital for providing such information: that is, at present, they have no viable alternatives.

9. The traditional method of using a census questionnaire can vary.  Especially designated enumerators can be used to complete the questionnaire or the self-enumeration method (by the household or the person being enumerated) can be used.  The questionnaire should be designed to take into account the method used and to comply with the recommended definitions and classifications.  The enumerator is a key person, filling in the questionnaire or giving advice and answering questions, as required.  Particular attention should be given to the local situation, and it may be useful to translate the questionnaires and instructions into different languages, and to use enumerators from the various national or ethnic groups who can speak the main languages of the country.

10. The data collection could involve both a short form (with selected questions) and a long form (with more questions).  The long form is completed for a sample of households or people.  Alternatively, one form could be used, but when this is done, a sample is often selected for processing certain questions: for example, those which could be costly to process, such as industry and occupation.

11. Some countries are using registers and other administrative sources, together with information from sample surveys, to provide census statistics.  Some countries have the possibilities to collect all relevant information by combining data from different registers.  Other countries can get part of the information from registers and other administrative sources - often information on persons - but have to supplement these by using questionnaires, particularly as there are difficulties in putting new items required for statistical purposes into administrative registers.

12. It is recommended that countries carry out a quality control programme.  This should cover each step in the census operation, from planning and data collection, through processing, to outputs.  Such measures could include, for example, checks on the enumerators' work, completeness of registers, independent/dependent sample checks on coding and keying, and follow-up surveys/comparisons with other sources on coverage and quality of answers.  A plan covering the whole programme should be produced and the results published.  It is recognized that, when basing information on the direct use of administrative records, the concepts may not correspond exactly to the definitions given in the recommendations. Some difficulties may occur in particular with concepts such as economic activity, contributing family members or cohabiting couples which are phenomena not directly covered by registers. When administrative records are used, one of the objectives of the quality control programme should be to document the extent to which the variables correspond to the recommendations.

13.  Six units of enumeration may be used in carrying out population and housing censuses:

In statistical terms, these concepts are clearly distinguishable, and the terms are not themselves interchangeable.  Some households contain more than one family, several households may live together in a housing unit and, exceptionally, a single household may occupy more than one housing unit as its usual place of residence. Similarly, a building may contain several housing units and a housing unit may, exceptionally, be located in more than one building, e.g. in the case of dwellings comprising a main building and a room or rooms above a detached garage that are clearly designed to be used as part of the dwelling.

14. Each of these units requires to be clearly defined, and definitions are set out in Part IV below (see paragraphs 182-191 () for definitions of household and family nucleus, paragraphs 229-235 () for living quarters and paragraph 270 () for building).

15. Living quarters and buildings have fixed locations and information on where they are is needed.  Information on households, however, and on the persons in households, can be collected and entered on the census questionnaire at the place of their usual residence and/or at the place where they are found on the day of the census. The procedure to be followed in the case of persons who are away from their usual residence at the time of the census is discussed in paragraphs 30-39 () below.

16.  One of the essential features of a census is that the population and the housing units etc. for the whole country are enumerated as nearly as possible in respect of the same well-defined point of time. Where this is a single census day, this is usually achieved by fixing a census moment at midnight at the beginning or end of census day.  However, the time of enumeration is sometimes used and this could cover several days.  New dwellings which have been completed and are ready for use at that moment should be included even though the completion of a census form for them does not take place until after the census moment, but dwellings in buildings which are in the course of construction should be included only if they are occupied at the time of the census. Housing units being demolished at the census moment should be excluded.

17. Similarly, each person alive up to the census moment should be included and counted as part of the total population, even though completion of the census form does not take place until later and the person has died in the interim. Infants born after the census moment should be excluded.

18. The data collected on the characteristics of living quarters and people should relate to a well-defined point in time or reference period but this need not be the same for all the data collected. For most items it will be "census day" or "census moment" but for items such as "rent" or economic characteristics it may be a specified period.

19. It is recommended that users in the public and private sectors be fully consulted about their needs on the content and outputs from the census.  Such consultations can cover many approaches, such as advisory committees, user surveys, and workshops.  While some basic statistics should be made widely available and free of charge, dissemination policies and practices will need to recognize any constraints imposed by national legislation and targets for income generation.

20. Outputs for users can vary from aggregate statistics to anonymised individual records, from standardized products to meeting ad hoc special needs, and from output on paper, such as published reports, to electronic dissemination.  Electronic dissemination can itself cover a wide range of types such as diskettes, CD-ROMs and databases which can be readily accessed by customers.  Further, census outputs are an important input to Geographical Information Systems.

21. It is recommended that full documentation on the outputs be provided for the users, including, where appropriate, metadata.  The documentation should cover such items as the questions, definitions, classifications, quality checks, methods etc.

22. The public needs to be assured of the confidentiality of the information collected in the census.  The confidentiality requirement encompasses the whole census operation, ranging from information on topics that the public provides to the content of census outputs, particularly for small areas or population groups.

23. The term "topic" is used to refer to the characteristics of persons or of groups of persons (households or family nuclei), or of living quarters or buildings containing dwellings for which data are collected in censuses. In any country the list of topics to be covered has to be considered in relation to other sources of data on the population and the housing situation, but in general the topics covered should be determined upon a balanced consideration of:

24. The list given below is divided into core topics and non-core topics. The list of core topics comprises those of basic interest and value to countries of the region, and it is recommended that countries cover these topics in their 2000 round of population and housing censuses (unless the data are available from other sources). The list of non-core topics will be dependent upon priorities which each country places on the information to be collected and the other factors described in para 23.  It will therefore be more difficult to obtain international comparability.

25. The list of core and non-core topics includes some topics which are referred to as derived topics.  Derived topics are generally those for which information is deduced from the inter-relationships between the replies given by a person to two or more questions in the questionnaire, from the replies to a particular question given by two or more persons, or from another source such as a register.  Such derived topics may, perhaps, be more correctly considered as tabulation components but they are included in the list of topics in order to emphasize the fact that the questionnaire should in some way yield the information needed to compile the recommended tabulations in which these variables appear. The derived topics are listed after the topics from which they are derived (or mainly derived, in those cases where a derived topic is derived from a combination of two or more topics), and are designated by means of letters in italics.  Icon following a topic name provides a link to the position in this document where that topic can be found.  Click on the icon to get to the text and use your browser's "back" button to come back.  However, it should be noted that not all topics have an accompanying descriptive text.

26. There may be additional topics that countries wish to collect information on in their censuses but which are not included in the ECE/Eurostat Recommendations, for example, impairments, disabilities and handicaps, and the informal sector.  Therefore, countries are invited to consult the World Recommendations^1/ for guidance concerning such topics.

27. Recommended definitions and classifications are given below for each of the core and derived core topics. Classifications are set out in detail and in some cases both basic and optional levels are indicated.

28. Suggested definitions and classifications are also given for many of the non-core and derived non-core topics, for the guidance of countries which may wish to include some of the topics in their censuses.

29. If necessary, the extra category "unknown" may be added to each classification, but in most cases this is not explicitly stated in the detailed recommendations.

30. Place of usual residence is the geographic place where the enumerated person usually resides; this may be the same as, or different from, the place where he/she actually is at the time of the Census; or it may be his/her legal residence. A person's usual residence should be that at which he/she spends most of his/her daily night-rest (but see paragraph 36 () for particular population subgroups).

31.  The new recommendations on international migration statistics^3/(), adopted at the 1997 session of the Statistical Commission, define a migrant as a person who changes his or her country of usual residence.

32.  A long-term international migrant is a person who moves to a country other than that of his or her usual residence for a period of at least a year (12 months), so that the country of destination effectively becomes his or her new country of usual residence.

33.  From the perspective of the country of departure, the person will be a long-term emigrant and from that of the country of arrival the person will be a long-term immigrant.  (This corresponds with place of usual residence one year prior to the Census (core topic 2)).

34.  A short-term migrant is a person who moves to a country other than that of his or her usual residence for at least three months but for less than a year.  Since these persons have their usual place of residence in another country, they should not be included in the count of the total population that usually resides in the country. However, if a country intends to obtain data from the census on short-term immigration flows, for that particular purpose countries should consider the country of usual residence of the short-term migrants to be the country of destination during the period they spend in the country.

35. In general, a person who is absent from his or her previous place/country of usual residence for one year or more should not be considered as temporarily absent.

36.  Although most persons will have no difficulty in stating their place of usual residence, difficulties may be encountered in a number of special cases. In particular, problems may arise in dealing with the following groups of persons:

The treatment of all these cases should be set out clearly in the census instructions and, if possible, objective rules should be formulated for dealing with them.  The treatment of each of these groups of persons should also be described in the census report and, where feasible, counts or estimates of the number of persons in each group should be given.

37. This topic is included in order to obtain the information needed for determining the total usually resident population of the country and for classifying the population by territorial divisions and by household status.

38. Where possible separate information should be collected for each household and for each person in a household, and for each person in an institutional household concerning:

39.  Information on place of usual residence should be collected in enough detail to enable tabulations to be made for the smallest geographic or administrative subdivisions required to meet users' needs for information on this topic.

40. A total usually resident population count for each territorial division would normally be compiled by adding groups 38(a) and 38(b). However, it is not always possible to collect information about persons absent from their place of usual residence (group 38(b)), particularly if a whole household is temporarily absent at the time of the census. Provision must therefore be made to collect information about such persons at the place where they are found at the time of the census (group 38(c)), and if necessary "transfer" them to their place or territorial division of usual residence.

41. The composition of the figure compiled for the total usually resident population (and other population totals compiled on other concepts) should be described in detail in the census report. The total usually resident population should usually include the following groups of persons:

The following groups should not normally be considered part of the total usually resident population but countries may wish to collect data on them to produce alternative population counts:

(j) foreign military, naval and diplomatic personnel and their families, temporarily located in the country;
(k) civilian aliens temporarily working in the country;
(l) asylum seekers. (Countries may wish to refer to chapter V - Recommendations on Asylum Statistics, of the Recommendations on Statistics of International Migration^1/()
(m) civilian aliens who cross a frontier daily to work in the country;
(n) civilian aliens other than those in groups (k) and (m) temporarily in the country e.g. tourists;

If feasible, the magnitude of groups (a) to (n) should be shown.

42. Each country should compile a figure for the total usually resident population on the basis of the national definition of this concept, and the detailed tabulations should in general be provided on this basis. In those countries where the total population figure has been corrected for under- or over-enumeration (usually measured by use of a post-enumeration survey or by comparison with other sources), both the enumerated figure and the estimated corrected population figure should be shown and described. The detailed tabulations will normally be based only on the population which was actually enumerated.

43. Some countries may wish to compile for national purposes one or more additional figures for the population such as the total present-in-area population, the total legally resident population or the population working in the country.

44. For census purposes, a locality is defined as a distinct population cluster, that is, the population living in neighboring buildings which either:

45. In applying this definition certain land-use categories should not be regarded as breaking the continuity of a built-up area (and accordingly should not be counted in applying the 200-metre criterion above). These categories are: industrial and commercial buildings and facilities, public parks, playgrounds and gardens, football fields and other sports facilities, bridged rivers, railway lines, canals, parking lots and other transport infrastructure, churchyards and cemeteries, etc.

46. This definition is intended to provide general guidance to countries in identifying localities and in determining their boundaries, and it may need to be adapted in accordance with national conditions and practices. The population not living in clusters as defined above may be described as living in scattered buildings. The definition of a locality adopted for the census should be given in detail in the census report.

47. Localities as defined above should not be confused with the smallest civil divisions of a country. In some cases, the two may coincide. In others, however, even the smallest civil division may contain two or more localities. On the other hand, some large cities or towns may contain two or more civil divisions, which should be considered only segments of a single locality rather than separate localities.

48. Countries are recommended to develop their census statistics for localities in accordance with national needs and possibilities. In doing so, they should try to approach as closely as possible the concept of the population cluster as defined above. Countries which tabulate statistics only for civil divisions should, as a minimum, endeavour to compile data on the total population of each part of a civil division containing a population cluster, or part of a population cluster, of at least 2,000 inhabitants and so provide a basis for making a more clear-cut distinction between urban and rural areas and populations (see paragraph 55 () below).

49. It is recommended that the population be classified by size of locality according to the following size-classes:

50. For national purposes as well as for international comparability, the most appropriate unit of classification for distinguishing urban and rural areas is the locality as defined in paragraph 39 () above. However, it is left to countries to decide whether to use the locality or the smallest civil division as the unit of classification.

51. Countries which use the smallest civil division as the unit are encouraged to endeavour to obtain results which correspond as closely as possible with those obtained by countries which use the locality as the unit. The approach to be adopted to achieve this aim depends mainly on the nature of the smallest civil divisions in the countries concerned. In some countries the smallest civil divisions are relatively small in area and in average number of inhabitants and generally do not contain more than one population cluster (or part of a larger population cluster). If it is not feasible for some of these countries to use the locality as the unit, they are encouraged to make use of the concept of the multi-communal agglomeration (i.e. to treat as single units groups of two or more contiguous minor civil divisions which form part of the same population cluster). It is also suggested that minor civil divisions at the periphery of such an agglomeration be included in the agglomeration if the major part of their resident populations live in areas belonging to the continuous built-up area of the agglomeration, and that minor civil divisions containing one or more isolated localities be classified according to the number of inhabitants of the largest population cluster within the unit.

52. The situation is different, however, in the case of countries in which the smallest civil divisions are relatively large in area and in average number of inhabitants and often contain two or more population clusters of varying sizes. If it is not feasible for some of these countries to use the locality as the unit, they should endeavour to use units smaller than minor civil divisions for this purpose, e.g. parishes, enumeration districts, grid squares, etc. They should endeavour to use these smaller units as building blocks and to aggregate them so as to correspond as closely as possible with the boundaries of localities in the same way as described above in the case of multi-communal agglomerations. If it is not feasible for some countries to adopt this approach, they should endeavour to develop new approaches to the classification of entire minor civil divisions in ways which will yield results that are as comparable as possible with those obtained by using the locality as the unit.

53. It is suggested that localities or similar units be grouped into the following five categories:

54. Countries are also encouraged to develop typologies of localities or similar areas based on additional criteria that could be used to distinguish different types of areas within particular categories of the suggested classification. For example, some countries may wish to subdivide category 1.0     (and in some cases category 2.0     as well) to distinguish agricultural localities from other types of small localities. Some countries may wish to subdivide one or more of the intermediate categories to distinguish market towns, industrial centres, service centres, etc. Some countries may wish to subdivide the large urban agglomerations included in categories 4.0     and 5.0     to distinguish various types of central and suburban areas. Extensions of the classification in these and other ways would enhance its analytical usefulness.

55. It is suggested that for purposes of international comparisons, countries define urban areas as localities with a population of 2,000 or more, and rural areas as localities with a population of less than 2,000 and sparsely populated areas. Some countries might also wish to consider defining urban areas in other ways (e.g. in terms of administrative boundaries, of built-up areas, of the area for which services such as shops, educational facilities, recreational facilities, employment, etc., are provided, or in terms of functional areas). Whatever approach is taken should be clearly described in the census report.

56. Place of usual residence one year prior to the census is intended to be the smallest civil division relevant for information on this topic in which the enumerated person's place of usual residence was located one year prior to the census.

57. This topic is included because the cross-tabulation of the population by place of usual residence at the time of the census and place of usual residence one year prior to the census will provide more information on internal migration within a country and immigration from abroad than is usually available from other sources. This applies, in particular, to data on the characteristics of the migrants. Although most countries in the region would probably collect information on this core topic through the census questionnaire, some might be able to obtain it from registers instead.

58. For the purpose of tabulating the population by migration status, persons under 1 year of age should be excluded and persons one year of age and older residing in a given area at the time of the census and those who resided in that area one year prior to the census should be classified as follows:

59. Duration of residence is the interval of time up to the date of the census, expressed in completed years, during which each person had usual residence in (a) the minor (or smallest relevant) civil division which is his usual residence at the time of the census and (b) the major civil division in which that minor civil division is located.

60. Information on duration of residence is only meaningful if it is cross-classified with usual residence at the time of the census. In collecting information on duration of residence, it should be made clear that the concern is mainly with length of residence in the major civil division and the minor civil division.

61. In addition to the place of usual residence one year prior to the census (core topic 2), some countries may ask for previous place of usual residence.  For tabulation purposes, the classification recommended in paragraph 58 () for core topic 2 is also applicable to this topic.

62. The sex of each person should be recorded in the census. If the information is missing from the questionnaire (or register), an allocation based on other entries for the individual should be made.

63. The need for further development of statistics analysed by gender has been identified by many countries in the region.  It is therefore important that countries ensure that the various definitions and classifications for data on educational attainment, economic activity status, occupation, position in the family and household, etc. are appropriately used in the census. Parallel data for both men and women should be provided for all appropriate topics.

64. To obtain information on age, it is recommended to collect information on date of birth. Collecting information on the date of birth has the advantage of permitting the tabulation of data in two ways - by year of birth and by completed years of age.

65. Persons whose age is not stated should generally be classified as a separate group. However, if the number of such persons is small, ages selected at random within a range that is appropriate to the other characteristics of the individual may be allocated to them in order to simplify the tabulation. Another useful approach would be to allocate the missing age by referring to another individual with similar characteristics and for whom age is stated. When such imputations are made, it is important to clearly describe both the method used and the number of imputations made in the census report.

66. Recommendations concerning the classification by age to be used in each of the relevant tabulations are given in section V.C. of the Recommendations. A classification by single years of age is recommended for some tabulations and a classification by five-year age groups for other tabulations.

67. Children, youth and the elderly have been identified by many countries in the region as special population groups for which various types of census data will be required. The types of data on children and youth that are likely to be of interest to countries include topics such as age, sex, marital status, and school attainment and/or educational attainment. For the elderly, data on age, sex, marital status, economic activity status, position in the family and household and type of living quarters are illustrations of some of the topics that are likely to be of interest to countries. It is recommended that countries ensure that the definitions and classifications that are planned to be used in the census for these and other topics of interest are appropriate for the types of data on children, youth and the elderly that will be required.

68. Marital status is defined here as the (legal) conjugal status of each individual in relation to the marriage laws (or customs) of the country (i.e. de jure status).

69. Information on the legal marital status of each person should be collected at least for persons aged 15 and over. However, since the minimum legal age (or the customary age) for marriage varies between countries and since the population may also include young persons who have been married in other countries with lower minimum ages, some countries may find it useful to collect the data for persons under 15 as well.

70. The following classification of the population by marital status is recommended:

71. It should be noted here that insofar as this recommended classification of legal marital status is concerned, all persons living in consensual unions should be classified as single, married, widowed or divorced in accordance with their de jure (legal) status.

72. The treatment of persons whose only or latest marriage has been annulled depends upon the relative size of this group. Where the group is substantial in size, it should be shown, if possible, as a separate basic category; if its size is insignificant, the individuals should be classified according to their marital status before the annulled marriage took place.

73. The census report should explain clearly the definitions of each tabulated marital status category, taking into account the enumeration procedures and the data-processing procedures. The explanation should also specify how groups such as the divorced, legally separated, de facto separated, consensually married and with an annulled marriage were treated.

74. Countries which have experienced increases in the number of persons living in consensual unions may wish to collect information not only on the de jure status but also on the de facto status. De facto marital status is defined here as the marital status of each individual in terms of his or her actual living arrangements. It is suggested that information on this topic be collected for persons of the same age categories as those for whom information on the legal status was collected.

75. It is to be noted that information on de facto marital status can also be derived from information collected on topics related to household and family characteristics of persons, characteristics of family nuclei and characteristics of private households.

76.  Place of birth is defined as the place of residence of the mother at the time of birth.  For persons born outside the country, it is sufficient to ask for the country of residence of the mother at the time of birth.  Place of birth is an important indicator for estimates of internal and international migration.  Information should be collected for all persons born in the country where the census is conducted as well as for all persons born outside the country.

77.  For purposes of international comparability as well as for internal use, information on country of birth should be collected on the basis of international boundaries existing at the time of the census.  It is recommended that the information on this topic be collected and coded in as detailed a manner as is feasible, based on the three-digit alphabetical codes presented in International Standard, ISO 3166-1:1997: Codes for the Representation of Names of Countries, (5th ed., Berlin 1997), published by the International Organization for Standardization. The use of these standard codes for the classification of country of birth will enhance the usefulness of such data for various purposes including an international exchange of foreign-born population statistics among countries.

78.  The following classification of birth place is recommended:

79.  Information on the country/place of birth of the father and the mother can also be collected.  This information is essential to understand processes of integration of immigrants and is particularly relevant in countries with high immigration rates or much concern about integration.  The question will, however, be difficult to apply in regions where boundaries have undergone many changes during the time period concerned.

80.  Citizenship is defined as the particular legal bond between an individual and his/her State, acquired by birth or naturalization, whether by declaration, option, marriage or other means according to the national legislation.  Information on citizenship should be collected for all persons and coded in as detailed a manner as is feasible, based on the three-digit alphabetical codes presented in International Standard, ISO 3166-1:1997: Codes for the Representation of Names of Countries, (5th ed., Berlin 1997), published by the International Organization for Standardization.

81. Persons with dual or multiple citizenship should declare all.  Separate data should be obtained for stateless persons.  Separate data should also be obtained for persons whose citizenship has not yet been clarified, following dissolution, separation or unification of States.

82. In countries where the population includes a significant proportion of naturalized citizens, it may be desirable to distinguish citizenship by birth or naturalization and other means according to the national legislation.  Some countries may also wish to include, for naturalized citizens, questions on previous citizenship, method of naturalization and year of acquisition.

83. Some countries may wish to collect information on the ethnic and/or national composition of their population.  Ethnic groups (and/or national groups) are made up of persons who consider themselves as having a same origin and/or culture, which may appear in linguistic and/or religious and/or other characteristics which differ from those of the rest of the population.  It depends on the historical and political circumstances whether countries consider such groups as ethnic groups and/or national groups.

84. Persons should be free to declare to which ethnic group and/or national group they belong.

85. Some countries may wish to collect data on languages.  Most relevant are:

86.  Some countries may wish to collect data on religion.  Most relevant are:

87. If this topic is included in the census it is suggested that information on total number of live-born children be collected for all women.

88. The data collected on total number of live-born children should, in principle, include all children born alive during the lifetime of the women concerned up to the census date (i.e. excluding foetal deaths). The number recorded should comprise all live-born children whether born of the present or prior marriage(s), whether born of consensual or other unions or by a single mother, and regardless of whether they are living or dead at the time of the census, or where they may be living. It is recognized that it may not be possible to specify in the enumeration instructions that children not born in a marriage or in a consensual union should be included.

89. Information on duration of marriage is valuable for fertility statistics and extends the knowledge that can be derived from data on number of live-born children. In the case of women who have been married more than once, it is suggested to obtain information on the dates of both the first marriage and the current marriage.

90. The "economically active" population comprises all persons who provide the supply of labour, as employed or as unemployed, for the production of goods and services^4/().  Economic activities, i.e. production, in the present context, include: (i) the production of all individual or collective goods or services that are supplied to units other than their producers, or intended to be so supplied, including the production of goods or services used up in the process of producing such goods or services (intermediate inputs); (ii) the own-account production of all goods that are retained by their producers for their own final use (final consumption or gross fixed capital formation); and (iii) the own-account production of domestic and personal services by employing paid domestic staff.

91. In principle, the production of all goods falls within the SNA production boundary, irrespective of whether the goods are intended for supply to other units or for the producers' own final use.  In practice, however, the production of a good for own final use within households should be recorded only if the amount of the good produced by households for their own final use is believed to be quantitatively important in relation to the total supply of that good in a country, and persons engaged in the production of goods for own final use within the same household should be considered as economically active only if such production comprises an important contribution to the total consumption of the household.  Examples of common types of household production include the production of agricultural products and their subsequent storage; production of dairy products such as butter or cheese; (note that the preparation of meals for immediate consumption is excluded); weaving cloth; dress making and tailoring; and construction of dwellings, and major renovations (e.g. replastering walls, repairing roofs) or extensions to dwellings.  For more details, see System of National Accounts, 1993 ^4/().

92. Domestic or personal services provided by unpaid household members for final consumption within the same household are excluded from the production boundary and, hence, are not considered to be economic activities i.e. production, in the present context.  (Examples are: (a) the cleaning, decoration and maintenance of the dwelling occupied by the household, including small repairs of a kind usually carried out by tenants as well as owners; (b) the use, cleaning, servicing and repair of household durables or other goods, including vehicles used for household purposes; 8 the preparation and serving of meals; (d) the care, training and instruction of children; (d) the care of sick, infirm or old people; and (e) the transportation of members of the household or their goods).  Persons engaged in such activities may be included among providers of non-paid social and personal services, see non-core topic 15 () (para 115 () below).

93. The "economically active" population can be measured in different ways: (a) the "currently active" population (or, equivalently, the "labour force"), measured in relation to a short reference period such as one week or one day; and (b) the "usually active" population measured in relation to a long reference period such as a year.

94. Information on activity status should be collected for each person at or above a minimum age set in accordance with the conditions in each country.  The minimum school-leaving age should not automatically be taken as the lower age limit for the collection of information on activity status.  Countries in which, normally, many children participate in agriculture or other types of economic activity (e.g. mining, weaving, petty trade), will need to select a lower minimum age than countries where employment of young children is uncommon. Tabulations of economic characteristics should at least distinguish persons under 15 years of age and those 15 years of age and over; and countries where the minimum school-leaving age is higher than 15 years and where there are economically active children below this age should endeavour to secure data on the economic characteristics of these children with a view to achieving international comparability at least for persons 15 years of age and over.  Use of a maximum age limit for measurement of the economically active population is not recommended, as a considerable number of elderly persons beyond retirement age may be engaged in economic activities, either regularly or occasionally.

95. To have a complete set of data compiled on the basis of both current and usual activity has advantages for a number of important uses, but this may be difficult in a census because of expense, limitations of questionnaire space and the burden of coding and processing.  Countries are recommended to collect information based on current activity first and if possible supplement this information with data based on usual activity.  However, it is recognized that some countries may prefer to collect information on the basis of the usual activity.  Countries using the concept of "usual activity" should endeavour to also obtain data covering at least the size of the "labour force" during a one-week period.

96. The "not economically active" population comprises all persons, irrespective of age, including those below the age specified for measuring the economically active population, who were not "economically active" as defined in paragraphs 90-92 () above.

97. Some "not economically active" persons may be classifiable to more than one category of the population not economically active.  It is recommended that in such situations, priority should be given to that of the possible categories which is listed first in paragraphs 104 () or 112 () below.

98. Current activity status is the current relationship of a person to economic activity, based on a brief reference period such as one week or one day. The use of the "current activity" is considered most appropriate for countries where the economic activity of people is not influenced much by seasonal or other factors causing variations over the year, and it is recommended that countries in the ECE region collect information in the census on activity status based on this concept (i.e., the "labour force" concept).  A time-reference period of one week should preferably be used, which may be either a specified recent fixed calendar week, or the last complete calendar week or the last seven days prior to enumeration.

The "currently active population" (i.e. the labour force)

99. The "currently active population" (the "labour force") comprises all persons who fulfil the requirements for inclusion among the employed or the unemployed as defined in paragraphs 100 () and 102 () below.

Employed persons

100. "'Employed' persons comprise all persons above a specified age who during the short reference period of preferably one week performed some work for pay or profit, in cash or in kind, or were temporarily absent from a job in which they had already worked and to which they had a formal attachment or from a self-employment activity such as a farm, a business enterprise or a service undertaking.  The census documentation and tabulations should clearly describe the time limit chosen as cut-off for considering persons to be 'at work'. According to the present international recommendations, the notion of 'some work' should be interpreted as work for at least one hour during the reference period. The one-hour criterion is an essential feature of the labour force framework embedded in the international definitions of employment and unemployment, and a prerequisite for the consistency of employment statistics with national accounts data on production. Countries concerned about the usefulness of the one-hour criterion for other users of census results should also collect data on 'time worked', following the recommendations of paragraphs 116-119 () below."

101.  Treatment of specific groups: The following treatment of certain groups of individuals is recommended:

• Persons in paid employment temporarily not at work because of illness or injury, holiday or vacation, strike or lock-out, educational or training leave, maternity or parental leave, reduction in economic activity, temporary disorganization or suspension of work due to such reasons as bad weather, mechanical or electrical breakdown, or shortage of raw materials or fuels or other temporary absence with or without leave should be considered as in paid employment provided they had a formal job attachment.  (This formal job attachment should be determined on the basis of one or more of the following criteria: a continued receipt of wage or salary; an assurance of return to work following the end of the contingency, or the agreement as to the date of return; or the elapsed duration of absence from the job which, wherever relevant, may be that duration for which workers can receive compensation benefits without obligations to accept other jobs)^5/();
• Self-employed persons (excluding contributing family workers) should be considered as "with enterprise, but not at work" if their absence from work is temporary and their enterprise meanwhile continues to exist;
• Contributing family workers should be considered to be at work on the same basis as other "self-employed" persons, i.e. irrespective of the number of hours worked during the reference period.  Countries which prefer for special reasons to set a minimum time criterion for the inclusion of contributing family workers among the "employed" should identify and separately classify those who worked less than the prescribed time, to be able to provide internationally comparable data;
• Persons engaged in economic activities in the form of own-account production of goods or services for own final use within the same household should be considered as in "self-employment" if such production comprises an important contribution to the total consumption of the household, (cf. paragraph 91 () above);
• Apprentices and trainees who received pay in cash or in kind should be considered in paid employment and classified as "at work" or "not at work" on the same basis as other persons in paid employment;
• Participants in job training schemes should be considered to be "employed" if the training took place within the context of an enterprise and in connection with its production, or if the participants could be said to retain a formal job attachment to an enterprise in which they had formerly been employed, even if the training was outside the context of the enterprise or without connection to its 'production'.  (Other participants in job training schemes may be considered to be 'unemployed'.)
• Students, homemakers and others mainly engaged in non-economic activities during the reference period, who at the same time were in "paid employment" or "self-employment" as defined above should be considered as employed on the same basis as other categories of employed persons and be identified separately, where possible;
• All members of the armed forces should be included among persons in paid employment.  The "armed forces" should include both the regular and the temporary members as specified in the most recent revision of the International Standard Classification of Occupations (ISCO).^6/()

Unemployed persons:

102. The "unemployed" comprise all persons above a specified age who during the reference period were:

(i) "without work", i.e. were not in paid employment or self-employment as defined above in paragraph 100 ();
(ii) "currently available for work", i.e. were available for paid employment or self-employment during the reference period; and
(iii) "seeking work", i.e. had taken specific steps in a specified recent period to seek paid employment or self-employment.  (The specific steps may include registration at a public or private employment exchange (for the purpose of obtaining job offers); application to employers; checking at work sites, farms, factory gates, market or other assembly places; placing or answering newspaper advertisements; seeking assistance of friends or relatives; looking for land, building, machinery or equipment to establish own enterprises; arranging for financial resources; applying for permits and licenses, etc).

103.  Treatment of specific groups: Some groups of persons require careful treatment to be properly included among the "unemployed".  The following treatment is recommended:

• Persons without work and currently available for work who had made arrangements to take up paid employment or undertake self-employment activity at a date subsequent to the reference period should be considered as "unemployed", irrespective of whether or not they recently sought work;
• Persons temporarily absent from their jobs with no formal job attachment who were currently available for work and seeking work should be regarded as "unemployed" in accordance with the standard definition of "unemployment".  Countries may, however, depending on national circumstances and policies, prefer to relax the seeking work criterion in the case of persons temporarily laid-off.  In such cases, persons temporarily laid-off who were not seeking work but classified as "unemployed" should be identified as a separate sub-category;
• Persons mainly engaged in non-economic activities during the reference period (e.g. students, homemakers), who satisfy the criteria for unemployment laid down in paragraph 102 () above should be regarded as "unemployed" on the same basis as other categories of "unemployed" persons and be identified separately, where possible.

The population not currently active (i.e. persons not in the labour force)

104. The "population not currently active" or, equivalently, "persons not in the labour force", comprises all persons who were neither "employed" nor "unemployed" during the short reference period used to measure "current activity".   It is recommended that this population be classified into the following four groups:

(a) "Students": persons not "currently economically active", who for most of the reference period attended any regular educational institution, public or private, for systematic instruction at any level of education. (See also non-core topic 'School attendance' (), paragraphs 174-176)
(b) "Pension or capital income recipients": persons, not "currently economically active", who receive income from property or investments, interests, rents, royalties or pensions from former activities.
(c) "Homemakers": persons, not "currently economically active", who for most of the reference period were engaged in unpaid household duties in their own home, for example, housewives and other relatives responsible for the care of the home and children.  (Domestic and personal services produced by domestic employees working for pay, however, are considered as economic activities in line with paragraph 90 () above).
(d) "Others": persons, not "currently economically active", who are receiving public aid or private support, and all other persons not falling into any of the above categories (e.g. children not attending school).

105. Usual activity status is the usual relationship of a person to economic activity based on a long reference period such as a year.

106. In countries where the economic activity of people varies widely over the year and where people are likely to be engaged in more than one type of economic activity during the year or to be seasonally unemployed, the "current activity" concept may not be considered as appropriate.  In such countries, the economic activity of people should be measured with reference to a longer period i.e. on the basis of the "usual activity" concept rather than on the basis of the "current activity" concept only.  If the concept of "usual activity" is adopted, a specified twelve-month period should be used as the reference period.  A long reference period such as the preceding 12 months will provide information on the year as a whole and thereby provide an opportunity for collecting information needed not only on the principal activity but also on any secondary activity.  It is also possible to obtain useful information on the intensity of activity over the year and relate it to household income for that period (if collected).  The main drawback of the usual activity approach is that it is susceptible to recall errors.  Another drawback is the problem of ascertaining the principal occupation and industry over a long period such as a year, unless an appropriate question or series of questions are introduced to identify a main job, which may be defined in terms of time worked or income earned.  Difficulties are also often encountered in measuring the "usual activity" status of persons who, though not usually active, have worked or were available for work at some time during the year.

The usually active population

107. The "usually active population" comprises all persons above a specified age whose main activity status, as determined in terms of number of weeks or days during a long specified period (such as the preceding 12 months) was "employed" or "unemployed" as defined in paragraphs 100 () and 102 () above with respect to the current activity during a short reference period.

108. In applying the above definitions of employment and unemployment in respect of the usual activity during a long reference period, it is necessary to determine the "main activity status" of each person above a specified minimum age.  For this purpose, one's main activity status may be conceived as a summary measure of the variable statuses of each person during the 52 weeks or the 365 days of the specified 12-month period.  The main activity status could be different as pointed out in the following paragraph depending on whether it is based on weeks or days as the unit of measurement.

109. In countries where employment is mostly of a regular and continuing nature and hence a week of employment generally means a week of full time employment or, at any rate, employment for a major part of the working time, it is suggested to base the main activity status on weeks of employment or unemployment.  The main activity status could also be determined on the basis of days of employment or unemployment, and this would be considered more appropriate for countries where employment is largely of an irregular nature and where a week of employment does not generally mean a week of full-time employment or even employment for a major part of the working time.

110. Two procedures may be followed to determine the main activity status of each person.  One is to interpret it as that status, usually active or not usually active, which prevailed over most of the 52 weeks (or most of the 365 days) during the specified reference year.  Another is to set a specific number of weeks (or days) as the cut-off point and classify anyone with at least that many weeks (or days) of employment and unemployment as belonging to the "usually active population".

111. Where the concept of "usually active population" is considered useful and feasible, the "usually active population" may be subdivided as "employed" and "unemployed" in accordance with the situation which prevailed most of the time, i.e "usually active" persons should be classified as "employed" if the number of weeks (or days) of employment is larger than or equal to the number of weeks (or days) of unemployment, and as "unemployed" if the number of weeks (or days) of employment is smaller than the number of weeks (or days) of unemployment.  As the subdivision as "employed" and "unemployed" is made among "usually active persons", the resulting classification by usual activity status may differ from a classification directly by main activity status during the reference year (i.e. when the distinction between "employed", "unemployed", and "not economically active" is made directly).  It is therefore recommended to construct the questionnaire in a way which makes it possible to dstinguish between "usually active" and "usually inactive" persons and among the former between "usually employed" and "usually unemployed" persons.

The population not usually active

112. The "population not usually active" comprises all persons whose main activity status during the long reference period used to measure usual activity was neither employed nor unemployed.  It is recommended that this population be classified into the following four groups:

(a) "Students": persons not "usually economically active", who for most of the reference period attended any regular educational institution, public or private, for systematic instruction at any level of education.   (See also non-core topic "school attendance" (), paragraphs 174-176).
(b) "Pension or capital income recipients": persons not "usually economically active", who receive income from property or investments, interests, rents, royalties or pensions from former activities.
(c) "Homemakers": persons not "usually economically active", who for most of the reference period were engaged in unpaid household duties in their own home, for example, housewives and other relatives responsible for the care of the home and children.  (Domestic and personal services produced by domestic employees working for pa