Survey of Labour and Survey of Labour and Income Dynamics (SLID)Income Dynamics (SLID)

All Congress SymposiumAll Congress Symposium“The riches of the Research Data Centres”“The riches of the Research Data Centres”

June 2, 2004June 2, 2004

University of Manitoba, WinnipegUniversity of Manitoba, Winnipeg Heather LatheHeather Lathe

Income Statistics DivisionIncome Statistics Division

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Points to coverPoints to cover

Survey design highlights, content, Survey design highlights, content, analytical usesanalytical uses

New content as of 2002New content as of 2002

Getting started: SLID retrieval system Getting started: SLID retrieval system (SLIDRET)(SLIDRET)

Also available in photocopies:Also available in photocopies:

Variance calculation – bootstrapVariance calculation – bootstrap

Sources for more informationSources for more information

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Original objectives of SLIDOriginal objectives of SLID

Labour market and income flowsLabour market and income flows Determinants of changeDeterminants of change Impacts on the familyImpacts on the family

Also:Also: Main source for cross-sectional income Main source for cross-sectional income

datadata

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Design highlightsDesign highlights

Longitudinal data, among the first at Statistics CanadaLongitudinal data, among the first at Statistics Canada Labour market and income data togetherLabour market and income data together A wide variety of additional “explanatory” variablesA wide variety of additional “explanatory” variables Family make-up and changes are keyFamily make-up and changes are key

TimeframeTimeframe Individuals followed for 6 year periodIndividuals followed for 6 year period Annual contact to update informationAnnual contact to update information

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Sample designSample design

Up to 2 interviews per yearUp to 2 interviews per year Labour in January and Income in May if no T1 Labour in January and Income in May if no T1

access permissionaccess permission Preliminary information asked during first contact Preliminary information asked during first contact

Reference year

1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

Panel 1

Panel 2

Panel 3

Panel 4

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Who is interviewed?Who is interviewed? Longitudinal respondents selected at start of Longitudinal respondents selected at start of

panelpanel

Cohabitants also interviewed (every member of Cohabitants also interviewed (every member of the household)the household)

Movers followed (longitudinal)Movers followed (longitudinal)

Labour, education and income collected for Labour, education and income collected for persons 16+, labour not collected 70+persons 16+, labour not collected 70+

Housing variables collected for every in-scope Housing variables collected for every in-scope household, disability for every personhousehold, disability for every person

10 provinces, non-institutional, off-reserve10 provinces, non-institutional, off-reserve

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2001 sample sizes2001 sample sizesPersons Persons HouseholdsHouseholds

CANADACANADA 62 50062 500 31 04731 047

NFLDNFLD 2 7652 765 1 2851 285

PEIPEI 1 7461 746 866866

NSNS 4 2544 254 2 1292 129

NBNB 3 8713 871 1 8821 882

QUEQUE 11 92811 928 6 1066 106

ONTONT 18 36618 366 8 8218 821

MANMAN 4 5974 597 2 3382 338

SASKSASK 4 3244 324 2 2372 237

ALBERTAALBERTA 5 2895 289 2 6432 643

BCBC 5 3605 360 2 7402 740

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Sample size by CMA – 2001 householdsSample size by CMA – 2001 households

TorontoToronto 1 546 1 546

MontrealMontreal 1 326 1 326

WinnipegWinnipeg 1 117 1 117

VancouverVancouver 957 957

Ottawa-GatineauOttawa-Gatineau 850 850

EdmontonEdmonton 737 737

CalgaryCalgary 653 653

Kitchener Kitchener 501 501

HalifaxHalifax 555 555

St.Catharines-NiagaraSt.Catharines-Niagara 455 455

Quebec CityQuebec City 523 523

LondonLondon 418 418

HamiltonHamilton 405 405

Victoria Victoria 321321

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SLID SLID contentcontent Over 1000 variablesOver 1000 variables Database organized into logically related Database organized into logically related

groups of variablesgroups of variables Database key variables:Database key variables:

person person jobjob job-absencejob-absence economic familyeconomic family household household household relationshipshousehold relationships monthly receipt of EI / WC /SAmonthly receipt of EI / WC /SA jobless spelljobless spell census familycensus family marital statusmarital status education certificateseducation certificates

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Organization of contentOrganization of contentPERSON

LABOUR INCOME & WEALTH

EDUCATION PERSONAL CHARACTERISTICS

LABOUR MARKET ACTIVITY PATTERNS

WORK EXPERIENCE

JOBLESS PERIODS

JOB INFORMATION

JOB CHARACTERISTICS

ABSENCES FROM WORK

EMPLOYER ATTRIBUTES

INCOME SOURCES

MONTHLY RECEIPT OF UI / WC / SA

ASSETS (not yet available)

EDUCATIONAL ACTIVITY

LEVEL OF SCHOOLING

DEMOGRAPHICS

ETHNO-CULTURAL

DISABILITY

CHILDREN

GEOGRAPHY

HOUSEHOLD & FAMILY INFO

TRAINING

HOUSING

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Employment and unemployment Employment and unemployment dynamics researchdynamics research

Gross changes in employment, unemployment and Gross changes in employment, unemployment and inactivity between months or yearsinactivity between months or years

Gross flow data of persons or jobs by industry, Gross flow data of persons or jobs by industry, occupation, worker characteristics and job occupation, worker characteristics and job characteristicscharacteristics

Duration of spells (jobs or unemployment)Duration of spells (jobs or unemployment) ExamplesExamples: :

To what extent are long spells of unemployment To what extent are long spells of unemployment experienced by the same individuals?experienced by the same individuals?

Why do people withdraw from the labour marketWhy do people withdraw from the labour market What precedes a transition into self-employment?What precedes a transition into self-employment?

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Life-cycle labour market Life-cycle labour market transitionstransitions

Labour market transitions associated with Labour market transitions associated with particular stages of life cycleparticular stages of life cycle

ExamplesExamples:: Transitions from school to workTransitions from school to work Transitions from work to retirementTransitions from work to retirement Work absences taken to raise childrenWork absences taken to raise children What are typical life-cycle patterns in Canada What are typical life-cycle patterns in Canada

today?today? What are the subsequent activities of high school What are the subsequent activities of high school

drop-outs, and what precedes a return to school?drop-outs, and what precedes a return to school?

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Job qualityJob quality

Examples:Examples: Wage differences between men and womenWage differences between men and women Job benefitsJob benefits UnderemploymentUnderemployment Career changeCareer change Career advancement and earningsCareer advancement and earnings Job polarization, e.g., in terms of wages and Job polarization, e.g., in terms of wages and

hours workedhours worked

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Family economic mobilityFamily economic mobility

ExamplesExamples:: How stable is family income?How stable is family income? What proportion of families experience a What proportion of families experience a

significant improvement or deterioration in significant improvement or deterioration in income between two points in time?income between two points in time?

What are the determinants of these changes?What are the determinants of these changes? How important are changes in family How important are changes in family

composition (divorce, remarriage) in explaining composition (divorce, remarriage) in explaining a change in financial well-being?a change in financial well-being?

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Dynamics of low incomeDynamics of low income

Incidence and duration of spells of low incomeIncidence and duration of spells of low income Factors associated with moves into or out of Factors associated with moves into or out of

low incomelow income ExamplesExamples::

Identifying the existence or otherwise of a Identifying the existence or otherwise of a “persistently poor” sub-population, and “persistently poor” sub-population, and associated characteristicsassociated characteristics

Studying flows into and out of low income in Studying flows into and out of low income in relation to government transfer programs and relation to government transfer programs and taxationtaxation

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Life events and family Life events and family changeschanges

Identifying the various types of families Identifying the various types of families and how families change, including step-and how families change, including step-families and multi-generational familiesfamilies and multi-generational families

What are the determinants or impacts of What are the determinants or impacts of “life events”?“life events”?

ExampleExample:: - What are the family’s economic circumstances - What are the family’s economic circumstances

preceding a marriage break-up, and what are they preceding a marriage break-up, and what are they for each spouse and any children following a for each spouse and any children following a separation?separation?

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Educational advancement and Educational advancement and combining school and workcombining school and work

Possible to view educational activity in the context Possible to view educational activity in the context of an individual’s other activities or family of an individual’s other activities or family circumstancescircumstances

ExamplesExamples:: Financial well-being, or family responsibilities, of Financial well-being, or family responsibilities, of

people pursuing post-secondary educationpeople pursuing post-secondary education To what degree do high school or post-secondary To what degree do high school or post-secondary

students combine work and schoolstudents combine work and school What is the labour market involvement of high What is the labour market involvement of high

school drop-outs and what precedes a return to school drop-outs and what precedes a return to schoolschool

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New contentNew content

Starting with 2002:Starting with 2002: HousingHousing Education/trainingEducation/training Geography – new baseGeography – new base

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Housing contentHousing contentFrom 1994 From 1994

dwelling tenure (rented/owned) and typedwelling tenure (rented/owned) and type

From 1999 From 1999 with/without mortgage; number of bedroomswith/without mortgage; number of bedrooms

From 2002 From 2002 the need for repairsthe need for repairs farm or home business operated from the propertyfarm or home business operated from the property Homeowners – shelter costs:Homeowners – shelter costs:

mortgage payments, utility costs mortgage payments, utility costs property taxes, condominium feesproperty taxes, condominium fees

Renters – shelter costs:Renters – shelter costs: monthly rent, utility costsmonthly rent, utility costs amenities included in the rent (parking, appliances, etc.)amenities included in the rent (parking, appliances, etc.) whether the rent is subsidised by government or an whether the rent is subsidised by government or an

employeremployer

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New housing research –New housing research –examplesexamples

Do changes in employment trigger a housing move?Do changes in employment trigger a housing move?

Is a new job or promotion associated with a move to Is a new job or promotion associated with a move to more suitable, affordable or adequate housing?more suitable, affordable or adequate housing?

What proportion of families experience a significant What proportion of families experience a significant improvement or deterioration in housing between two improvement or deterioration in housing between two points in time?points in time?

How important are changes in family composition How important are changes in family composition (divorce, remarriage) in explaining a change in (divorce, remarriage) in explaining a change in suitability, affordability or adequacy of housingsuitability, affordability or adequacy of housing??

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Education coverageEducation coverage

More complete in 2002More complete in 2002 secondary schoolsecondary school community collegecommunity college business schoolbusiness school vocational schoolvocational school universityuniversity courses, workshops, seminars courses, workshops, seminars training related to employmenttraining related to employment

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Education – Education – collected characteristicscollected characteristics

Main subject / subjects of coursesMain subject / subjects of courses Reason for choosing area of study Reason for choosing area of study Goals related to current or future employmentGoals related to current or future employment Employer supportEmployer support Number of monthsNumber of months Number of weeksNumber of weeks Number of hours per weekNumber of hours per week Total number of hoursTotal number of hours Full time / part time Full time / part time Area of studies - code Area of studies - code Receipt of certificate or diplomaReceipt of certificate or diploma

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New education-related researchNew education-related research

Impact of programs offered by elementary and high Impact of programs offered by elementary and high schools, trade schools, colleges, CEGEPs and schools, trade schools, colleges, CEGEPs and universitiesuniversities

gender, level of education, age, job tenure, labour market gender, level of education, age, job tenure, labour market experience and occupation. experience and occupation.

Life-long learningLife-long learning

Does training have impact on career progress or Does training have impact on career progress or income?income?

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Geography Geography

Census 2001 geography introducedCensus 2001 geography introduced 1992-1998 keeps 1991 geography1992-1998 keeps 1991 geography From 1999 new geographyFrom 1999 new geography Some variables needs to be recoded back to Some variables needs to be recoded back to

19921992 Old 1991 geography Old 1991 geography

Old information for recoded variables and Old information for recoded variables and years 1999-2001 stored in new “old years 1999-2001 stored in new “old geography” variablesgeography” variables

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Access to confidential Access to confidential microdatamicrodata

Custom data retrievalsCustom data retrievals

On-premises access On-premises access Research Data CentersResearch Data Centers

Remote access Remote access

SLIDRET – in RDC’sSLIDRET – in RDC’s

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SLID database retrieval SLID database retrieval software (software (SLIDRETSLIDRET))

Produces a flat rectangular file in Text (ASCII) Produces a flat rectangular file in Text (ASCII) format to eliminate the requirement to format to eliminate the requirement to understand the database structureunderstand the database structure

By producing this study file, you get started on By producing this study file, you get started on some of the main choices for your study…some of the main choices for your study…

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SLIDRET basic inputs SLIDRET basic inputs

Type of analysis: longitudinal or cross-Type of analysis: longitudinal or cross-sectional, and years of study.sectional, and years of study.

Unit of analysis: Person, Person-job, Unit of analysis: Person, Person-job, Family, Various spells , etc. (11 Family, Various spells , etc. (11 choices in all).choices in all).

Browse the variable descriptionsBrowse the variable descriptions

Loads the appropriate weight field Loads the appropriate weight field according to other specifications.according to other specifications.

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SLIDRET variable choiceSLIDRET variable choice

Pick variables of interest.Pick variables of interest.

Can add weights (on top of default one)Can add weights (on top of default one)

If desired, possible to restrict the If desired, possible to restrict the population and sort the file.population and sort the file.

Note: SLIDRET prevents the user from Note: SLIDRET prevents the user from making inconsistent choices.making inconsistent choices.

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SLIDRET outputsSLIDRET outputs Output file in text formatOutput file in text format

Output file in dbf formatOutput file in dbf format

Record layoutRecord layout

Data dictionaryData dictionary

Variable labelsVariable labels

Code setsCode sets

Univariate statisticsUnivariate statistics

Query - saved for future use or Query - saved for future use or modificationsmodifications

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Variance estimationVariance estimation

SLID uses bootstrap variance estimationSLID uses bootstrap variance estimation

Bootstrap - replication method (process done Bootstrap - replication method (process done 1000 times1000 times):): n is the number of PSUs in a stratumn is the number of PSUs in a stratum (n – 1) PSUs selected by Simple Random (n – 1) PSUs selected by Simple Random

Sampling with replacement in each stratum to Sampling with replacement in each stratum to obtain a bootstrap sub-sampleobtain a bootstrap sub-sample

Set of bootstrap weights calculatedSet of bootstrap weights calculated

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Bootstrap weightsBootstrap weights

Bootstrap weights are available for SLID Bootstrap weights are available for SLID reference years 1996-2001reference years 1996-2001

For all types of weightsFor all types of weights Cross-sectional weight (ICSWT26)Cross-sectional weight (ICSWT26) Labour weight (ILBWT26)Labour weight (ILBWT26) Longitudinal weight for each panel (ILGWT26)Longitudinal weight for each panel (ILGWT26) Combined panels longitudinal weight (ILWCP26)Combined panels longitudinal weight (ILWCP26)

1000 sets of weights1000 sets of weights

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When to use bootstrapWhen to use bootstrap Bootstrap variance estimation can be Bootstrap variance estimation can be

done for all direct estimates:done for all direct estimates: totals, means, proportions, medians, totals, means, proportions, medians,

percentiles, parameters from a regression, percentiles, parameters from a regression, etc etc

Works for estimation of fixed effects Works for estimation of fixed effects does not for random effectsdoes not for random effects technical reason - few PSUs in first stage of technical reason - few PSUs in first stage of

samplingsampling E.g.,E.g.,

multilevel modelingmultilevel modeling random effects models random effects models

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Why to use bootstrapWhy to use bootstrap

Bootstrap variance estimation accounts Bootstrap variance estimation accounts for complex survey design, specifically:for complex survey design, specifically: cluster samplecluster sample non-uniform response mechanismnon-uniform response mechanism

Use it for population modelsUse it for population models to account for sample designto account for sample design

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How to estimate the varianceHow to estimate the variance

1.1. Calculate regular estimate Calculate regular estimate θθ

2.2. Execute the estimation program using each set of Execute the estimation program using each set of

bootstrap weights (1000 sets) and keep each bootstrap weights (1000 sets) and keep each

resulting estimate resulting estimate θθii, i=1, 2, …, 1000., i=1, 2, …, 1000.

3.3. The following formula estimates varianceThe following formula estimates variance

1000

1i

2i )(

999

1Variance θθ

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Which bootstrap weights to useWhich bootstrap weights to use

Always use the bootstrap weights that Always use the bootstrap weights that correspond to the weight used to produce the correspond to the weight used to produce the estimateestimate if an estimate is produced using the cross-sectional if an estimate is produced using the cross-sectional

weight (ICSWT26) for 2001, then the bootstrap weight (ICSWT26) for 2001, then the bootstrap cross-sectional weights for 2001 should be used cross-sectional weights for 2001 should be used for variance estimationfor variance estimation

In order to maintain the maximum precision, In order to maintain the maximum precision, all 1000 weights should be used, especially all 1000 weights should be used, especially for estimations on small domainsfor estimations on small domains

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More info availableMore info available

A document on how to calculate variance A document on how to calculate variance estimation is available in RDCsestimation is available in RDCs

Some SAS macros and related Some SAS macros and related documentation, as well as examples of documentation, as well as examples of programs doing bootstrap estimation with programs doing bootstrap estimation with SLID data, will be available in a near futureSLID data, will be available in a near future

More information from Longitudinal Data More information from Longitudinal Data Analysis Group at StatscanAnalysis Group at Statscan

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Survey overviewSurvey overview

Like internet “home page” just for SLIDLike internet “home page” just for SLID www.statcan.cawww.statcan.ca: “: “Our products & services”; Our products & services”;

“Free”; “Personal finance & household finance”“Free”; “Personal finance & household finance” OverviewOverview Products & servicesProducts & services Notes, definitions, methodologyNotes, definitions, methodology QuestionnairesQuestionnaires Research papersResearch papers Data dictionaryData dictionary

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For more information on For more information on SLIDSLID

Contact the Client Services Section atContact the Client Services Section at

income@statcan.caincome@statcan.ca

or toll-free at or toll-free at

1-888-297-73551-888-297-7355oror

951-7355951-7355