University of Dar es Salaam Institute of Statistics, Nov 2003

1. University of Dar es SalaamInstitute of Statistics, Nov 2003 Household Structure and the Census Gunnar Thorvaldsen Norwegian Historical Data Centre

2. 1801 in Denmark, Iceland and Norway • 925000+880000+25000 • World’s first census? • Completely digitized • N & DK can be searched • No common interface • No birthplace When is a census, a census? Goyer (1986): 1. National legal authority 2. Defined enumeration area 3. Complete coverage 4. Simultaneous enumeration 5. Individual enumeration 6. Periodic enumeration7. Publication of results8. Dissemination of results

3. 27 Tussøen First Last name Sex Family Marital stat Occupation Year Place of birth Hans Hagerup Brox M Hf G Farmer Fisher 1827 Sara Brox K Hf G Farmer wife 1845 Albert Brox M S U Son 1874 Edevard Brox M S U Son 1877 Nekolai Brox M S U Son 1885 Anne Gunders. K Tj U Servant girl 1860 Lenvik 27 Tussøen Johanne Brox K Hm E Grocer’s widow, farmer 1836 Tromsø Regine Brox K D U Daughter 1875 Else Anders. K Tj U Servant girl 1876 7 Tussøen J Hans A. Brox M Hf G Farmer Fisher 1833 Margrethe Brox K Hm G Farmer’s wife 1841 Berg i Senjen Tr Else M. Brox K D U Daughter 1873 Daniel Brox M S U Son 1874 Haakon Brox M S U Son 1884 Hans M. Brox M S U Son 1886 Johanne Brox K D U Daughter 1869 Magnhild Ols. K Pld U Step daughter 1897 Karoline Karls. K Pld U Step daughter 1891 Mette Øyen K Tj U Servant girl 1879 Tromsøsund Lorentine Karesius. K Forsør. U Poor relief 1840 Edvard Antons. M Hf G Fisher, lodger 1873 Tromsøsund Dorthea Brox K Hm G Lodgerwife 1879 Trygve Johans. M S U Son 15061899 Tussøy 1900

4. Census microdata: Person number Age Sex 12100102600700720000011210000104 22200202600700720000011210000104 32300100600700720000012123000000 42300200400700000000000000000000 52300200200700000000000000000000 62300200000700000000000000000000

5. NAPP North Atlantic Population Project 2001-2005 Integrated with constructed variables • Britain 1881 29 mill • Canada 1881 4.3 mill • USA 1880 50 mill • Iceland 1870 70000 1901 72000 • Norway 1865 1.7 mill 1900 2.2 mill

6. IPUMS internationalMinnesota Population Centerhttp://ipums.org Future additions: Brazil, China, Hungary, Spain IPUMS Latin America Other countries pending Strict confidentiality rules Registered users

7. Extraction system

8. On a millennial scale, censuses and census microdata survive for only a short, but significant period

9. The population census goes globalCoverage becomes universalContent becomes uniformDecennial censuses become the norm

10. Increasingly uniform, principal source on population

11. Preserve against accident, deterioration and technological obsolescence • Microdata: - transfer to stable media - use standard data storage protocols - entrust copies with at least two depositories • Metadata: collect, catalogue, and reproduce - Enumeration forms (preserve all versions used) - Enumerator and data processing instructions - Codebooks (photocopies and scanned images) - Technical studies, evaluations, reports (UN Statistical Division: entire archive deposited, being scanned)

12. Globalization of the census & the coming census microdata revolution • 1. Census microdata: the historical NAPP project • 2. The population census went global in 20th century: coverage, periodicity, and content • 3. Liberating census microdata: preservation, anonymization, integration, & dissemination • 4. Statistical confidentiality and census samples: a 36 year-long perfect record • 5. International norms of statistical confidentiality • 6. Harmonizing and disseminating scientifically anonymized census samples on the Internet