General comparability of censuses

Edward Higgs

The censuses are the most important source for understanding the long-term development of the social, economic and demographic structures of Britain in the nineteenth and early twentieth centuries. Although each is a snapshot taken every ten years, their results, published in the various census reports, can be compared over time to show secular trends. Historians and social scientists can use them to study population growth, changes to the housing stock, shifts in household structures, changing migration patterns, evolving occupational structures, the use of various languages, and numerous other subjects. Since the Census reports give information by various administrative sub-units as well as nationally, local and regional patterns can be studied over time and compared. The original manuscript returns containing the information supplied by householders also survive and can be used to ask questions not covered in the published Reports. Without the source our understanding of the past would be greatly impoverished.

However, as with all historical sources, there are some problems of comparability over time. Those attempting to use information from differing censuses to identify trends need to be aware of these pitfalls, lest they confuse real changes with statistical artefacts. This is not to deprecate the attempt to study such trends, merely to urge caution, and attention to the secondary works of interpretation on the census records (e.g. Higgs, 1989; Lawton; Office of Population Censuses and Surveys, and General Register Office, Scotland; Wrigley). Given care, and an understanding of the limitations of the source, robust results can be produced. Many of the problems of comparability between the censuses fall under four main headings:

1) changes to the questions asked at the differing censuses;

2) changes to the coverage of certain topics in the census reports;

3) changes to the classification systems used to analyse certain heads of information in the census reports;

4) changes to the boundaries of the administrative units for which information is given in the census reports.

It is difficult to compare data in the censuses if the information sought changed over time. The censuses from 1801 to 1831, for example, asked for far less information than those from 1841 onwards (Higgs, 1989, 5–15). Thus, no information on where people were born was collected before 1841, and even then it was not until 1851 that the name of the place of birth was required. Employment status only appeared as a subject of enquiry in 1891. Questions could also disappear from the census, as in the case of those relating to medical disabilities after 1911. As the 1921 General report for England and Wales put it, the question on infirmities had been omitted, 'in view of the generally recognised fact that reliable information upon these subjects cannot be expected in returns made by or on behalf of the individuals afflicted' (Census of England and Wales 1921, General report with appendices, 2). More subtle changes in the questions asked could also have important implications. Thus, in the period 1851 to 1881 the instructions to householders indicated that the female relatives of farmers or lodging-house keepers were to be put down on the census schedule as having an occupation such as 'Farmer's Wife'. But this instruction disappeared in 1891, and may cause problems of comparability across these years (Higgs, 1987). Similarly, the instructions on how to define a 'lodger' changed over time, which may affect studies of household structure (Higgs, 1989, 58–60).

Even if the information was collected in the census, this does not mean that it was necessarily reported on in the same manner in the census reports for differing years. Thus the 1841 Census reports reported the data it collected in terms of the ancient counties, hundreds and principal towns, whilst in later years the main divisions used were based on the civil registration system – divisions, registration counties, districts and sub-districts. Some runs of data go down to levels of detail in one set of Reports that might not be replicated in subsequent censuses, and visa versa. Thus, the smallest area for which tables of birthplaces were given in the census reports was registration districts, but these only appeared in the Reports 1851 and 1861 (Lawton, 151).

The tabulation of data in the censuses, and their publication in the Census reports, often required some form of condensation. The manuscript census returns contained, for example, tens of thousands of individual occupational titles, which had to be grouped under headings in order to create tables that conveyed meaning. But the conventions used in this process changed over time as intellectual fashions, ideas and priorities changed (Higgs, 2004a). This can mean that the terms that appear in such tables do not cover the same sorts of workers in differing census years. Thus, the term 'scientific person' used in the mid-nineteenth century census tables meant something very different to what we mean by the term 'scientist' today, and was undergoing changes in the course of the late nineteenth century (Higgs, 1985). Similar problems can be found in the use of terms such as 'clerk', 'warehouseman', and 'carters' (Higgs, 2005, 159–63). The 1881 General report noted itself that the data on commercial clerks was not comparable between 1881 and 1871 (Census of England and Wales, 1881, General report 34). It is important, therefore, to study the existing interpretative guides to the census data, the footnotes to tables, and even the occupational dictionaries used to place occupations in categories, before making rash statements about occupational trends.

The administrative units in which census data was reported in the Census reports also changed over time. In part this reflected the changing administrative arrangements in the country as a whole. Thus, urban and rural sanitary districts only appeared in the Census reports for 1881 because they had only been set up by the Public Health Acts of 1874 and 1875. But they were, in turn, abolished by the 1894 Local Government Act, which transformed them into general-purpose urban districts and rural districts within the framework of administrative counties. However, even administrative units of the same type and name could change over time as parcels of land were taken from them, or added, according to administrative convenience. In the period 1894 to 1898, for example, the General Register Office (which administered the census) noted 797 changes to registration districts; 1,603 changes to parochial boundaries; and 211 changes to urban districts (Higgs, 2004b, 112). When establishing local trends it is important, therefore, to consult the footnotes in tables and local gazetteers to determine if administrative boundaries have changed.

REFERENCES

Census of England and Wales, 1881, Vol. IV. General Report BPP 1883 LXXX.583. [View this document: England and Wales, Vol. IV. General report, 1881]

Census of England and Wales, 1921. General report with appendices (London: HMSO, 1927). [View this document: General report, England and Wales, 1921]

Edward Higgs, 'Counting heads and jobs: science as an occupation in the Victorian census', History of Science, 23, 1985, 335–49.

Edward Higgs, 'Women, occupations and work in the nineteenth-century censuses', History Workshop Journal, 23, 1987, 59–80.

Edward Higgs, 'The linguistic construction of social and medical categories in the work of the English General Register Office', in S. Szreter, A. Dharmalingam and H. Sholkamy, eds, The qualitative dimension of quantitative demography (Oxford, 2004a), 86–106.

Edward Higgs, Life, death and statistics: civil registration, censuses and the work of the General Register Office, 1837–1952 (Hatfield, 2004).

Richard Lawton, ed., The Census and Social Structure: an Interpretative Guide to Nineteenth Century Censuses for England and Wales (London, 1978).

Office of Population Censuses and Surveys and the General Register Office, Edinburgh, Guide to Census Reports, Great Britain 1801–1966 (London, 1977).

E. A. Wrigley, ed., Nineteenth-century Society (Cambridge, 1972).