Survey of Labour and Income Dynamics (SLID)

Summary of changes

Activity on this program started: 1993

Reference period of change - 2011

This is the last release from the Survey of Labour and Income Dynamics and contains cross-sectional estimates only. Effective with the 2012 reference year, cross-sectional income estimates will be available from the Canadian Income Survey (record number 5200).

Longitudinal estimates are available up to and including 2010.

For detailed information related to previous SLID releases, please click on the "Other reference periods" sidebar.

Reference period of change - 2010

This release is accompanied by a historical revision for 2006 to 2009. The Survey of Labour and Income Dynamics estimates for 2006 and the years following are now produced on the basis of population counts from the 2006 Census of Population, instead of the 2001 Census. As a result, tables and charts presented in the report, as well as all those in the CANSIM 202 series, have been revised for that period.

This is the last release of longitudinal data from the Survey of Labour and Income Dynamics.

Reference period of change - 2009

Ontario material deprivation (OMD) data were collected for the 2009 reference year. The data are available only for households in Ontario. The data were collected on behalf of the Ontario Government in order to inform their poverty reduction plan. Ontario households were asked about ten items which were selected based on research by the Daily Bread Food Bank of Toronto, the Metcalf Foundation and the Caledon Institute of Social Policy. For each item, up to two questions were asked. The first question asked whether an item was available to the household during the 2009 reference year, and if not, the second question asked if the household could not afford it. For example, all Ontario households were asked whether they ate fresh fruit and vegetables every day; only those households that did not were asked if they did not because they could not afford to do so.

Reference period of change - 2008

New approaches to low income:

Analysis of low income is now done at the person level and makes use of several complementary lines and several statistics. Statistics will no longer be reported at the family level, but instead at the individual level, where each individual is represented by his or her adjusted family income or adjusted household income depending on the line used. These lines are : the Low Income Cut-offs (LICOs), the Low Income Measures (LIMs) and the Market Basket Measure (MBM). The Market Basket Measure was developed by the Department of Human Resources and Skills Development Canada. Lastly, some new statistics are being introduced. In addition to the number and percentage of persons below a certain cut-off, users will also find new measures of the depth of low income, in which the low income gap is expressed as a percentage of a given cut-off or relevant aggregate income.

Use of a different equivalence factor:

In order to ensure international consistency and to facilitate the calculation of adjusted family income, a new scale will now be used. From now on, adjusted family income will be obtained by dividing family income by the square root of the number of members in the family. The estimates for past years have been revised accordingly. With respect to the LIM, the square root of the number of persons in the household will be used.

Sampling - New Panel:
17,196 new households have been selected to form Panel 6.

Geography Revision:

SLID data always follow the geographic design of a particular Census. With this year's release, SLID geography variables were revised from the 2001 to the 2006 Census-based geography design. Reference years prior to 1999 follow the boundaries of the 1991 Census geography-base; reference years 1999 to 2004 follow the 2001 Census geography-base; and reference years 2005 and on, follow the 2006 Census geography-base.

Reference period of change - 2007

The Survey of Labour and Income Dynamics adopted Statistics Canada's new classification systems for industry and occupation, using the North American Industry Classification System 2007 (NAICS) and the National Occupational Classification - Statistical 2006 (NOC-S) respectively. These changes have the following impact on SLID data:

The greatest change introduced by this revision was within the telecommunications area of the Information and Cultural Industries sector. The updates made to this sector reflect the rapid changes in the structure of these industries, including the merging of activities.

With two exceptions, all NAICS 2007 revisions occurred within sector boundaries. The exceptions were: (1) Real Estate Investment Trusts, which moved from the Finance and Insurance sector to the Real Estate and Leasing sector; and (2) Executive Search Consulting Services, which moved from the Professional, Scientific and Technical Services sector to the Business, Building and Other Support Services sector.

The structure of NOC-S 2006 remains unchanged from that of NOC-S 2001. No major groups, minor groups or unit groups have been added, deleted or combined, though some groups have new names or updated content. Therefore, the SLID data was not impacted by this revision.

Reference period of change - 2006

New version of SLID database:

The Survey of Labour and Income Dynamics (SLID) database is expanding this year to include micro-data from the cross-sectional Survey of Consumer finance (SCF) from 1976 to 1997 inclusive.

Some of the SCF information is now available through the SLID entities database. This will permit users to access a longer period of historical data from a unique database. Users still have the choice of using the SCF historical files, if it better suits their needs.

Data from SCF were adapted as much as possible to SLID concepts variables. Some concepts were almost identical between the two surveys, such as income data, allowing SCF variables to be easily transformed into SLID variables. Nevertheless, other SCF concepts differed and thus some variables were modified to follow SLID concepts. For example because the SCF 'head of family' concept differs from the SLID «major income earner» concept, variables related to the family characteristics were converted.

Most of the income variables as well as others, such as demographic information, were converted in this release.

Reference period of change - 2005

Student loans:

Since 2005, three student loan variables have been introduced. Those variables indicate whether respondents already received a student loan, what the total amount borrowed was and how much has not been repaid. For more information, please see the section Survey Content - Education.

Labour weight change in 2005 - historical revision of labour weight from 1993 to 2004:

The original labour weight was modified to help users who had to deal with a large amount of missing data. The purpose of the labour weight modification was to reduce the number of individuals with a non null labour weight with no information from the labour interview. Before the change, the labour weight used the definition of respondents at the household level. That meant that if at least one person in a household answered the labour component, everyone in that household, aged 16 years or older, was considered a respondent and thus had a non null labour weight, even if they had not responded at the labour interview. With the new labour weight, everyone with a non null weight responded at least partially at the labour interview.

Reference period of change - 2004

Starting this year (2004), the Survey of Labour and Income Dynamics adopted Statistics Canada's new classification systems for industry and occupation, using the North American Industry Classification System 2002 (NAICS2002) and the National Occupational Classification - Statistical 2001 (NOC-S) respectively. These changes have the following impact on SLID data:

1) The changes in industry classification led to reclassification within the construction industry, and within the information and cultural industry, but did not change aggregate industry level statistics for these two industries. None of the other 14 industries were affected.
2) The changes in occupation classification were primarily focused on occupations concentrated within the information technology field, where much greater detail and precision is now possible. As well, certain occupation codes which were determined to have similar duties and responsibilities have been combined to form groups that are more homogeneous in nature.

Data sources - In previous years, the Survey of Labour and Income Dynamics (SLID) conducted a Labour interview each January and a separate Income interview in May. In 2005 (reference year 2004) the two interviews were combined and collected in one interview in January.

Imputation - Improvements in the imputation methods were introduced for 2004 and applied to past years in a historical revision. A description of these changes is available in the publication Housing Data in the Survey of Labour and Income Dynamics (75F0002MIE2006007, free).

Reference period of change - 2003

The switch from 1996 to 2001 Census-based population totals for recent years and the use of T4 information from CRA were introduced with the release of data for 2003. SCF estimates from 1990 to 1995 and SLID estimates from 1996 to 2002 were revised back to 1990 at the same time.

Revisions and seasonal adjustment - 2003 Historical revision:

Every few years, estimates produced by the combined program of the Survey of Labour and Income Dynamics (SLID) and the Survey of Consumer Finances (SCF) undergo a revision. The 2003 revision is the result of three modifications.

1) All estimates, back to 1990, are adjusted to population projections based on the 2001 Census population counts.

2) Starting with 1990 estimates, wages and salaries are benchmarked to the distribution of wages and salaries derived from the T4 statement of remuneration remittance file.

3) The 1992-base low income cut-offs (LICOs) themselves have been revised, resulting from a revision of the 1992 Family Expenditure Survey. SLID and SCF estimates were revised from 1980. Along with the two changes described above, this has an impact on levels of low-income statistics.

Reference period of change - 2002

From 1994 to 2001, the survey covered only a few housing characteristics, primarily ownership status and dwelling type. In 2002, with the start of sponsorship from Canada Mortgage and Housing Corporation (CMHC), several other characteristics and detailed shelter costs were added to the survey. Several imputation methods were also introduced at that time, in order to replace missing values due to survey non-response and to provide utility costs, which contribute to total shelter costs. A description of these changes is available in the publication Housing Data in the Survey of Labour and Income Dynamics (75F0002MIE2006007, free).

Reference period of change - 1998

As of reference year 1998, this survey became a sample survey, with a cross-sectional design with a longitudinal follow-up.

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