Ethnic group and the British census: the search for a question

"The 1991 census contained, for the first time, a question on the ethnic group of each member of the population of Great Britain. This paper reports on how a question was developed which has a sufficiently high degree of acceptance from all the main ethnic groups, and which is answered sufficiently accurately, to justify inclusion in the census."     

Proposals for 2001 samples of anonymized records: An assessment of disclosure risk

In 1991 Marsh and co-workers made the case for a sample of anonymized records (SAR) from the 1991 census of population. The case was accepted by the Office for National Statistics (then the Office of Population Censuses and Surveys) and a request was made by the Economic and Social Research Council to purchase the SARs. Two files were released for Great Britain—a 2% sample of individuals and a 1% sample of households. Subsequently similar samples were released for Northern Ireland. Since their release, the files have been heavily used for research and there has been no known breach of confidentiality. There is a considerable demand for similar files from the 2001 census, with specific requests for a larger sample size and lower population threshold for the individual SAR. This paper reassesses the analysis of Marsh and co-workers of the risk of identification of an individual or household in a sample of microdata from the 1991 census and also uses alternative ways of assessing risks with the 1991 SARs. The results of both the reassessment and the new analyses are reassuring and allow us to take the 1991 SARs as a base-line against which to assess proposals for changes to the size and structure of samples from the 2001 census.     

Computer systems to support census geography

The development of computer systems that support the geography of the census in Canada is described. The authors "present proposals for the 1991 Census that increase the level of automation, whether the geography changes or not. In addition, opportunities for change and improvement, should the geography change, are outlined. To minimize the risks involved, it is important to give these different proposals serious consideration early in the planning of a census."     

The case for samples of anonymized records from the 1991 census

"The census of population represents a rich source of social data. Other countries have released samples of anonymized records from their censuses to the research community for secondary analysis. So far this has not been done in Britain. The areas of research which might be expected to benefit from such microdata are outlined, and support is drawn from considering experience overseas. However, it is essential to protect the confidentiality of the data. The paper therefore considers the risks, both real and perceived, of identification of individuals from census microdata. The conclusion of the paper is that the potential benefits from census microdata are large and that the risks in terms of disclosure are very small. The authors therefore argue that the Office of Population Censuses and Surveys and the General Register Office of Scotland should release samples of anonymized records from the 1991 census for secondary analysis."     

A methodological strategy for a one-number census in the UK

As a result of lessons learnt from the 1991 census, a research programme was set up to seek improvements in census methodology. Underenumeration has been placed top of the agenda in this programme, and every effort is being made to achieve as high a coverage as possible in the 2001 census. In recognition, however, that 100% coverage will never be achieved, the one-number census (ONC) project was established to measure the degree of underenumeration in the 2001 census and, if possible, to adjust fully the outputs from the census for that undercount. A key component of this adjustment process is a census coverage survey (CCS). This paper presents an overview of the ONC project, focusing on the design and analysis methodology for the CCS. It also presents results that allow the reader to evaluate the robustness of this methodology.     

Address register research for the 1991 census of Canada

"The current Canadian census is based on the local enumerator who lists and visits each dwelling in his/her enumeration area to drop off the questionnaires just before census day. Other approaches to compiling an address list exist, however. This paper describes current research into the use of an address register for the next Canadian census, to take place in 1991. Possible applications of an address register are described, earlier research is summarized and potential sources for an address register in the Canadian context are mentioned. The paper concludes with a number of concerns which must be addressed in addition to the more technical issues."     

Third-order inference for autocorrelation in nonlinear regression models

We propose third-order likelihood-based methods to derive highly accurate p-value approximations for testing autocorrelated disturbances in nonlinear regression models. The proposed methods are particularly accurate for small- and medium-sized samples whereas commonly used first-order methods like the signed log-likelihood ratio test, the Kobayashi (1991) test, and the standardized test can be seriously misleading in these cases. Two Monte Carlo simulations are provided to show how the proposed methods outperform the above first-order methods. An empirical example applied to US population census data is also provided to illustrate the implementation of the proposed method and its usefulness in practice.     

Coverage of the Great Britain census of population and housing

The extent of the undercount in the 1991 U.K. census and its consequences are described. The author notes that "the 1.2 million non-response, the difference between the published census figure and the final population estimate, is concentrated among young adults aged 20-34 years, particularly males, but includes significant numbers of young children and of very elderly people (80 years old and older)." Ways to reduce the level of non-response in future censuses are discussed.     

The case for small area microdata

Summary.  Census data are available in aggregate form for local areas and, through the samples of anonymized records (SARs), as samples of microdata for households and individuals. In 1991 there were two SAR files: a household file and an individual file. These have a high degree of detail on the census variables but little geographical detail, a situation that will be exacerbated for the 2001 SAR owing to the loss of district level geography on the individual SAR. The paper puts forward the case for an additional sample of microdata, also drawn from the census, that has much greater geographical detail. Small area microdata (SAM) are individual level records with local area identifiers and, to maintain confidentiality, reduced detail on the census variables. Population data from seven local authorities, including rural and urban areas, are used to define prototype samples of SAM. The rationale for SAM is given, with examples that demonstrate the role of local area information in the analysis of census data. Since there is a trade-off between the extent of local detail and the extent of detail on variables that can be made available, the confidentiality risk of SAM is assessed empirically. An indicative specification of the SAM is given, having taken into account the results of the confidentiality analysis.     

Accuracy of the 1990 census and undercount adjustments

"In July 1991 the [U.S.] Census Bureau recommended to its parent agency, the Department of Commerce, that the 1990 census be adjusted for undercount. The Secretary of Commerce decided not to adjust, however. Those decisions relied at least partly on the Census Bureau's analyses of the accuracy of the census and of the proposed undercount adjustments based on the Post-Enumeration Survey (PES).... This article describes the total error analysis and loss function analysis of the Census Bureau. In its decision not to adjust the census, the Department of Commerce cited different criteria than aggregate loss functions. Those criteria are identified and discussed."     

The 1988 general census in light of the expected recommendations of the CMEA Permanent Statistical Commission

The author describes a set of principles concerning census procedures agreed to by the countries of the Council for Mutual Economic Assistance. These include an agreement to conduct a decennial census at the end of each decade and close to the beginning of a year, and an agreed number of minimum and optimum components. Dates of future censuses include: Poland, 1988; USSR, 1989; Mongolia, 1989; Viet Nam, 1989; Romania, 1990; Hungary, 1990; Cuba, 1990; Czechoslovakia, 1990; German Democratic Republic, 1991; Yugoslavia, 1991; and Bulgaria, 2000.     

1991 Austrian population census

The author describes the basic methodology employed in the 1991 Austrian census as well as the topics covered. Lessons from the Austrian experience that could be applied to Soviet censuses are considered.     

The socioeconomic structure of the population

The author discusses plans for the next all-Union population census in the USSR, with a focus on gathering data on socioeconomic characteristics.     

Census data quality--a user's view

"This paper presents the perspective of a major user of both decennial and economic [U.S.] census data. It illustrates how these data are used as a framework for commercial marketing research surveys that measure television audiences and sales of consumer goods through retail stores, drawing on Nielsen's own experience in data collection and evaluation. It reviews Nielsen's analyses of census data quality based, in part, on actual field evaluation of census results. Finally, it suggests ways that data quality might be evaluated and improved to enhance the usefulness of these census programs."     

非抽样误差视角下普查涵盖误差及其模型研究

根据普查数据生成过程,将实际普查汇总结果与目标总体真值的净误差定义为普查涵盖误差;从非抽样误差的作用分析,提出涵盖误差来源影响的三个假设,并论证采用净误差表现普查涵盖误差的合理性。在此基础上,将涵盖误差的产生机制和普查数据汇总模型结合,构建不同普查类型下计数与内容涵盖误差的模型与误差分解过程;以此论述了非抽样误差对涵盖误差的影响作用,以及计数涵盖误差和内容涵盖误差间的联系,为进一步研究普查数据质量评估与控制奠定理论基础。     

Ethnic differences in the labour market: a comparison of the samples of anonymized records and Labour Force Survey

The public use sample from the 1991 UK census makes it possible to conduct individual level analyses of ethnic minorities' educational and occupational attainments. Unfortunately, however, the census asked only about higher level qualifications obtained after reaching 18 years of age. A comparison with the Labour Force Surveys (LFSs) shows that the census gives in some respects a misleading impression of qualifications among the first-generation members of ethnic minorities: the LFS data show that ethnic minorities tend to be more polarized in their qualifications than the British-born whites, with relatively large proportions at the two extremes, either with degrees or with no qualifications at all. It follows that the census's treatment of qualifications may tend to exaggerate the scale of disadvantage of ethnic minorities in the labour market, and particularly in access to the salariat where qualifications play a particularly large role in recruitment. Regression analyses of sample of anonymized records and LFS data confirm these expectations although they indicate that the results of the census are not seriously misleading as regards the pattern of ethnic disadvantages in the competition to avoid unemployment. The LFS data also confirm earlier findings that the ethnic penalties are in general of similar magnitude among the second generation to those among the first generation, despite the substantial equalization of educational experience that has taken place. There is some evidence that disadvantages in access to the salariat may have been reduced, but this is counterbalanced by the evidence that disadvantages in the avoidance of unemployment may have deteriorated.     

Recent work with microcomputers for census processing in developing countries

The use of microcomputers to process census data in developing countries is discussed. Specifically, the authors describe the Integrated Microcomputer Processing System (IMPS) developed by the U.S. Bureau of the Census and focus "on the recent experience of Burkina Faso and Senegal in using microcomputers. A summary is given of the use of IMPS by an increasing number of countries. Additionally, this paper describes the latest enhancements and future plans for IMPS. It concludes with some thoughts on the use of microcomputers in the areas of data collection and processing, as well as in the use and dissemination of census data."     

Understanding the 2001 UK census migration and commuting data: the effect of small cell adjustment and problems of comparison with 1991

Summary.  Origin–destination statistics have been produced from the last three UK censuses. The paper describes what is new about the 2001 census interaction data on migration and commuting, considers the disclosure control methods that were applied to cells containing small values and demonstrates the problems that are associated with making comparisons with 1991 data. The effect of small cell adjustment procedures on the interaction data sets is investigated by means of selective analyses at different spatial scales. Some recommendations are made in light of the problems that were manifest in 2001.     

Monte Carlo exact methods used for analysing interethnic unions in Great Britain

The value of using exact rather than asymptotic tests to measure intermarriage in the United Kingdom is examined. "We develop Markov chain Monte Carlo methods for estimating the exact conditional p-value and the exact distribution of the residuals, for quasi-independence and quasi-symmetry. These methods are used to analyse a sparse 10 x 10 symmetric table of interethnic unions, extracted from the 1% household sample of anonymized records from the 1991 U.K. census. With the exception of Pakistani/White and Other Asian/White unions, there is no evidence against quasi-symmetry. We conclude that, with these exceptions, there are no gender differences in the affinities between ethnic groups."     

Combining census and registration data to estimate detailed elderly migration flows in England and Wales

Summary.  A log-linear model is developed to estimate detailed elderly migration flows by combining data from the 2001 UK census and National Health Services patient register. After showing that the census and National Health Service migration flows can be reasonably combined, elderly migration flows between groupings of local authority districts by age, sex and health status for the 2000–2001 and 2003–2004 periods are estimated and then analysed to show how the patterns have changed. By combining registration data with census data, we can provide recent estimates of detailed elderly migration flows, which can be used for improvements in social planning or policy.