Notes on Census Data
Census Data
The data files provide population and employment data from the Canadian Censuses
of 1961, 1971, 1981, 1986, and 1991. The level of geograpic aggregation is the
census subdivision (csd), and the geographic scope is the province of Ontario.
Data is available for males, females, and both. The coverage for 1971 through
1991 is complete, and the data for these years is from Census Canada magnetic
tapes held by the University of Toronto Data Library. The coverage for 1961 is
incomplete, and comes from bound volumes published by Census Canada.
Census Geography
Census Canada defines several different geographic hierarchies. See the Appendix
"Census Geography" for details. The enumeration area/census subdivision/census
division/province hierarchy is the most important here, because CICA towns
correspond closely to census subdivisions. Data came off the census tapes
aggregated either to the enumeration area or to the census subdivision. In the
former case, aggregation of enumeration areas to census subdivisions was done in
the SPSS control files that extracted the data from tape.
Census divisions are counties, (e.g. Simcoe County) united counties, (e.g.
Prescott and Russell United Counties) districts, (e.g. Algoma District) regional
municipalities, (e.g. Hamilton-Wentworth Regional Municipality) or metropolitan
municipalities. (e.g. Toronto Metropolitan Municipality) Census divisions do not
overlap, and collectively exhaust the entire province.
Census subdivisions in Ontario are boroughs, (e.g. East York) cities, (e.g.
Scarborough) towns, (e.g. Ajax) villages, (e.g. Bancroft) townships, (e.g. Essa)
improvement areas, Indian reserves, Indian settlements, and unorganised. Census
divisions do not overlap, and collectively exhaust all census divisions. Census
subdivions types, as these designations are known, are sometimes misleading.
Typically, a town csd covers a small area within the limits of a community, and
a township csd covers a larger rectangular area surrounding a town. Often,
however, a town csd covers an area similar to that of a township. Any serious
user of the data should look carefully at a census map before using data that
relate CICA towns to csds.
Census Data
The data files give six population and employment variables for each csd in each
year, for males, females, and both. Population and population 15 years and over
have the obvious definition. Labour force and employment are generally
understood, and their exact definitions are available in the references below.
Employment income and income base have different definitions in the different
years. In 1961, income base is total wage-earners, and employment income is
average earnings of wage-earners. In 1971, income base is number reporting
positive and negative employment income, and employment income is average
positive and negative employment income. In 1981, 1986 and 1991, income base is
number with employment income, and employment income is average employment
income. These terms are defined in the following Census Canada documents. The
codes in parentheses are Census catalogue numbers.
1961 Census: Labour Force (94-547)
1971 Census: Labour Force Activity (94-771 through 94-784)
1981 Census: 1981 Census Dictionary (99-901)
1986 Census: 1986 Census Dictionary (99-101E)
1991 Census: Census Dictionary (92-301)
Coverage
Data for 1971, 1981, 1986, and 1991 is from magnetic tape, and is complete: data
is available for all census subdivisions. 1961 data is from bound volumes, and
is incomplete. Only population is available for all 1961 census subdivisions.
Table 7 in "Population: Counties and Subdivisions: Ontario" (catalogue number
92-533 gives "population" for every census subdivision. Table 4 and table 5 in
Labour Force: Employment Status by Sex (94-533) give "population 15 years of
age and over", "labour force", and "experienced labour force with jobs"
(employment) for city, town, and village csds having a population of 1000 or
more. Table 13 in "Labour Force: Earnings and Weeks of Employment of Wage
Earners: Provinces and Incorporated Centres (94-534) gives "total wage earners"
and "average earnings" for city, town, and village csds having a population of
1000 or more. Even after the above restrictions, only those csds in 1961 that
have the same name in 1961 and 1971 are included in the data files. These
include all csds with CICA towns within them. Some of the csds have different
boundaries in 1961 and 1971.
Access to Census Tapes
Census magnetic tapes are held at the University of Toronto Data Library. Users
of the library cannot access the tapes directly. Users consult lists of
available data, look up code books for the data they want, and write SPSS or SAS
contol files to read the data off the tapes. I can provide the names of the
tapes and the SPSS control files to anyone who is interested.
Groups
Almost all of the population of Ontario is found in csds of type city, town,
village, and township. All towns with accountants in them are also within csds
of these types.
From census to census, csd boundaries change. Most of these changes involve many
csds becoming one csd. Cases where one csd becomes many, or many csds become
many are less frequent. There are also some infrequent and minor boundary
changes where csds lose territory to to other csds.
In every year except 1960, city, town, village, and township csds were
aggregated to form groups so that there was a one-to-one mapping between the
groups of one year and the groups of any other. This allows comparison of census
data from year to year. Census maps from 1960 do not show individual csds. For
this reason, grouping is restricted to other years.
The files 70to80 and 85to90 list the
cases where csd boundaries change from 1971 to 1981 and from 1986 to 1991,
respectively. It is organized into mappings from N csds in the earlier year to M
csds in the later year. The mappings are separated by blank lines. The M later
year csds are listed first, without indentation, in the format cd csd. The N
earlier csds are listed after, indented two spaces, in the format cd csd. There
are cases where M=1 and N=1. These mark csds whose cd code and/or csd code
changes from one year to the next.