Under-enumeration in the census

Edward Higgs

It is probable that there was under-enumeration in the British censuses of the nineteenth and early twentieth centuries. However, in the absence of another source to check it against it is difficult to say how great this under-enumeration was, or how far it was compensated for by double counting. This is especially true of the censuses of 1801 to 1831 undertaken by John Rickman. He sent census schedules to overseers of the poor, clergymen, and schoolmasters in Scotland, and asked them to place the numbers of people in their parishes in various categories (Higgs, 1989, 5–7, 114–19). This might have led to under-enumeration, but also to a possible exaggeration of populations, and to double counting. The overseers would have had a quite accurate idea of parish populations, at least in the countryside, but the results must have been fairly rough and ready.

In the early censuses taken by the General Register Office (GRO) from 1841 onwards, certain groups, usually those not living in conventional households, were simply not enumerated by name. These included the members of the Royal Navy on board ship in 1841, and possibly 1851; all members of the merchant marine in 1841, and various sections of it thereafter; all fishermen afloat in 1841, and sections of this group thereafter; the crews of vessels engaged in inland navigation in 1841 and 1851; and in theory all itinerants, travellers and nightworkers in 1841, and probably a considerable number of them in later years. Soldiers serving abroad were not enumerated by name in the Victorian period (Higgs, 1989, 37–46). It is likely that some categories of people were under-enumerated, such as the very young aged under one year, middle-aged women, or foreign nationals (Census of England and Wales, 1881, Vol. IV. General Report, 17; Census of England and Wales, 1891, Vol. IV General Report, 28, 64). But this would be compensated for by over-enumeration in categories elsewhere — of children aged one year, young female adults, naturalised citizens (Higgs, 1989, 67–70, 74).

In all probability some people and households that should have been enumerated slipped completely through the census net. Some of these omissions might be due to clerical error as enumerators and householders made slips in recording or copying. This must have been especially true of the period prior to 1911, when census enumerators had to copy the householders' schedules into their enumeration books from which tabulation was done by the GRO in London. A wife might have been absent because of an enumerator's copying blunder; an elderly visitor might have been temporarily lost sight of; an apprentice 'mislaid' by a busy householder; and so on. But in some districts, or amongst some social groups, it might have been difficult for hard-pressed enumerators to ensure that they had handed a household schedule to every family. This must have been especially true in the 'rookeries' of mid-Victorian London. In some cases, people on the margins of society may have been suspicious of all authority, and avoided the enumerator if at all possible (Higgs, 2004, 86–7).

There is certainly evidence from recent censuses to suggest such problems. The post-enumeration surveys for the 1981 census indicated that 0.5 per cent of households were omitted in England and Wales. In Inner London in 1981, however, the under-enumeration may have been as much as 2.75 per cent (Whitehead, 46). Under-enumeration was still higher in 1991. In 2001 there may have been a million people, mainly young men, who were missing from the census — the difference between the actual enumeration and the total estimated from rolling forward the corrected 1991 figures. The Office for National Statistics, the modern successor to the GRO, claimed that the discrepancy was due to emigration that had not been picked up, although some doubt that this would explain the gender bias of the discrepancy.

Little work has been done in a similar vein for the British censuses of the nineteenth and early twentieth centuries. Wrigley and Schofield have calculated that the censuses of 1841 to 1871 record approximately 5 per cent fewer children aged under five years than would be expected from civil registration data, although this may reflect problems with age recording rather than under-enumeration (Wrigley and Schofield, 589–90). The findings of some preliminary studies in the USA have suggested that approximately 15 per cent of adults were omitted in the censuses of that country in the mid-nineteenth century (Steckel, 593). Coverage in American cities may have been worse than in the countryside, especially amongst the poor and marginal groups, such as servants (Parkinson, 514). Such levels of under-enumeration are probably exaggerations, and may not be typical of nineteenth-century Britain, especially given the different manner in which the US censuses were administered.

In the absence of reliable evidence to the contrary, it is probably necessary to take the figures in the Census Reports at face value. However, in certain places, and with respect to certain groups of people it might be wise to use them with some caution.

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, 1891, Vol. IV General Report, with summary tables and appendices BPP 1893–4 CVI. [View this document: General report, England and Wales, Vol. IV, 1891]

Edward Higgs, Making sense of the census. The manuscript returns for England and Wales, 1801–1901 (London, 1989).

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, 2004), 86–106.

D. H. Parkinson, 'Comments on the underenumeration of the U.S. census, 1850–1880', Social Science History, 15 (1991), 509–16.

R. H. Steckel, 'The quality of census data for historical enquiry: a research agenda', Social Science History, 15 (1991), 579–99.

Frank Whitehead, 'The GRO use of social surveys', Population Trends, XLVIII (1987), 45–54.

E. A. Wrigley and R. S. Schofield, The population history of England 1541–1871 (London, 1981).