Historical Canadian census aggregate statistics

1. Historical Canadian census aggregate statistics A workshop with: Laine Ruus and Chuck Humphrey May 30, 2004

2. Outline • Introduction • Changes to census products • Changes to variable collection and coding • Changes to units of observation • Changes to file organization • Changes to census geography • Following a geographic area over time

3. Introduction • Study of change over time is increasingly interesting, as data time-lines get longer • Most historical census products are print-only, computer-readable exists for some products beginning in 1961 • STC only made extensive use of computer equipment with the 1951 census

4. Introduction (cont’d) • Working with historical census aggregate data involves dealing with: • Changes to census products • Changes to variable collection, coding, and definitions • Changes to file organization • Changes to units of observation • Changes to census geography

5. Census products by geographic area and medium • Enumeration area: 1961-1996 • Never available in print • Dissemination area: 2001 • Computer-readable only • Census tract: • Print: 1951-2001 • Computer-readable: 1971-2001 • Provincial census tracts • Print: 1981 • Computer-readable: 1971-1981

6. Census products by geographic area and medium (cont’d) • Census subdivision (municipalities) level • Print: 1871-2001 • Computer-readable: 1971-2001 • CMA/CA • Print: 1871-2001 • Computer-readable: 1971-2001 • Federal electoral district level • Print: 1871-2001 • Computer-readable: 1971-2001

7. Census products by geographic area and medium (cont’d) • Province level • Print: 1871-2001 • Computer-readable: 1971-2001 • Forward sortation area level • Never in print • Computer-readable: 1986-2001

9. Changes to variable collection, coding, and definitions • Current definitions in census dictionnaires • Available for each census from 1971 and on, see individual census web pages linked at: http://www.chass.utoronto.ca/datalib/major/major.htm#can • 2001 census dictionary contains historical changes in coding, but only for variables contained in the 2001 census

10. Changes to variable collection, coding, and definitions (cont’d) • Technical reports published by STC examining comparability of census variables/data over time • Canadian Century Research Infrastructure (CCRI) project intends to compile papers outlining the historical changes to major census variables http://www.canada.uottawa.ca/ccri/

11. Changes to file organization • 1961 • all variables cross-tabulated with gender and/or rural/urban area only, • multiple tables per physical file • Enumeration area level files only

12. Changes to file organization • 1971 • Self-enumeration introduced • Random rounding introduced • Introduction of CMA concept (urban area+commuters) • Multi-dimensional (n x m) tables • Summary records at higher geographies in each file • Files at 4 major levels of geography: EA, CT & PCT, CSD, and municipalities 5k and over • Like files bundled in physical files • Also introduced first public use microdata files

13. Changes to file organization (cont’d) • 1981 • Indian reserves became separate census subdivisons • Introduction of computer-readable profile files • Introduction of area suppression (?) • 1986 • Each cross-tabulation becomes one file • Files at enumeration area, census tract, and census subdivision levels only • Summary records at higher levels of geography dropped

14. Changes to file organization (cont’d) • 1991 • Files at enumeration area, census tract, and census subdivision levels only • 1996 • BCT files for 5 levels of geography, profile files originally for 6 levels • 2001 • BCT files at 7 geographic levels, profile files for 11 levels of geography

15. Changes to unit of observation • Now 5 basic units of observation: individual, census family, economic family, household, dwelling • 1871 – individual • 1921 – ‘census family’ versus ‘private family’ • 1931 – ‘private family’ became ‘household’ • 1956 – ‘economic family’ introduced

16. Brief guide to census geography: what changes and why • Enumeration areas were the basic building block • Did not cross other STC boundaries • Therefore could be added up to all higher levels of geography • Area covered by one enumerator • Not geographically stable (ie could and did change with each census

17. Brief guide to census geography: what changes and why (cont’d) • Dissemination areas introduced in 2001 • DAs replace EAs as smallest geographic area for which census data are released • DAs only respect CD boundaries • Planned to be geographically stable • Dissemination areas are comprised of Blocks • The new basic building block • No standard data products except population and dwelling counts at block level

18. Census Geography (cont’d) • Census tracts • first defined in 1941 census, as ‘social areas’ • renamed census tracts (1951) • census tracts first defined in urban areas • urban census tracts split when they grow too big (and STC has the budget to split them)

19. Census Geography (cont’d) • Area aggregates/Provincial census tracts • Created in 1971, as ‘area aggregates’ • 1976 became provincial census tracts • covered all Canada outside census-tracted urban areas • no print publications, only BCTs, in 1971 • 1981 included in BCTs and print profile • disappeared in 1986 census

20. Census geography (cont’d) • Census subdivisions (municipalities) • Defined by provincial/territorial Municipality Acts + unincorporated areas • See: Interim list of changes to municipal boundaries, status, and names http://www.chass.utoronto.ca/datalib/codebooks/cstdli/92f0009xpb.htm • add up to census divisions

21. Changes to census geography (cont’d) • Indian reserves • Indian reserves defined by IAND • 1961 Indian reserves lumped together in each county • 1971 Indian reserves lumped together in each census subdivision (municipality) • 1981 Indian reserves became discrete census subdivisions

22. Census geography (cont’d) • Census divisions/counties, etc. • defined by provincial legislation (some provinces only), • otherwise defined by Stats Can • Census metropolitan areas/census agglomerations • Defined by urban core plus commuters (STC defined) • Federal electoral districts • Defined by federal Electoral Boundary Readjustment Acts, about every 10 years.

23. Adding up census geography • The following table shows which levels of census geography can be added up to which larger levels of census geography

25. Changes to census geography • Three methods of tracking changes to census geography over time • Correspondence tables • Overlay vector files • Manually

26. Correspondence files • Correspondence files are available for: • Enumeration areas: 1971 – present • Census tracts, • Available for 1991-1996, 1996-2001 • Prior years printed in census tract profile volumes • UT/DLS has created file of 1966-1971 • Municipalities: see Interim list of changes to municipal boundaries, 1965 – • Indicate only whether or not there has been a change, not how much

27. To overlay vector files • Need vector files for each census. A list of files available at UT, see: http://www.chass.utoronto.ca/datalib/major/spmapagg.htm • Require appropriate GIS software

28. Manually • You will need print maps of the areas at each census • A list of print map resources at UT is at: http://www.chass.utoronto.ca/datalib/major/prmapag.htm • Alternatively, use the Official lists (1961-1981), and Geosuite (1996- ) • Difficult to track down from some censuses, as these are not official publications with DBS/STC catalogue numbers

29. Tools to add up census geography • Geographic coding in census files • Reference tools: • Official lists/Enumeration area reference lists • Geography tape files (1971-1991) • Geosuite

31. Now for an exercise • Retrieve aggregate statistics with most detailed coding of ethnic origin at census tract level from 1981, 1971, and 1961 census • From basic summary tabulations files • For a geographic area larger than a census tract, but smaller than a census subdivision