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

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 enumeration 7. Publication of results 8. Dissemination of results

3. 27Tussøen FirstLast nameSexFamilyMarital stat OccupationYearPlace of birth Hans Hagerup BroxMHfGFarmer Fisher1827 SaraBroxKHfGFarmer wife1845 AlbertBroxMSUSon1874 EdevardBroxMSUSon1877 NekolaiBroxMSUSon1885 AnneGunders.KTjUServant girl 1860Lenvik 27Tussøen JohanneBroxKHmEGrocer’s widow, farmer 1836Tromsø RegineBroxKDUDaughter1875 ElseAnders.KTjUServant girl1876 7TussøenJ Hans A.BroxMHfGFarmer Fisher 1833 MargretheBroxKHmGFarmer’s wife 1841Berg i Senjen Tr Else M.BroxKDUDaughter1873 DanielBroxMSUSon1874 HaakonBroxMSUSon1884 Hans M.BroxMSUSon1886 JohanneBroxKDUDaughter1869 MagnhildOls.KPldUStep daughter1897 KarolineKarls.KPldUStep daughter1891 MetteØyenKTjUServant girl1879Tromsøsund LorentineKaresius.KForsør.UPoor relief1840 EdvardAntons.MHfGFisher, lodger1873Tromsøsund DortheaBroxKHmGLodgerwife1879 TrygveJohans.MSUSon15061899 Tussøy 1900

4. 12100102600700720000011210000104 22200202600700720000011210000104 32300100600700720000012123000000 42300200400700000000000000000000 52300200200700000000000000000000 62300200000700000000000000000000 Census microdata:

5. NAPP North Atlantic Population Project Britain 1881 29 mill Canada 1881 4.3 mill USA1880 50 mill Iceland 1870 70000 1901 72000 Norway 1865 1.7 mill 1900 2.2 mill 2001-2005 Integrated with constructed variables

6. IPUMS international Minnesota Population Center http://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 global Coverage becomes universal Content becomes uniform Decennial 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 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