LifePaths

1
LifePaths

• How much does data availability influence the
  model?
• Geoff Rowe
• IMA2007 Conference, Vienna, August 20-22, 2007

2
LifePaths Two Lessons Learned

• Model a process, not a data set!
• Data Gaps no single data set will ever be
  sufficient need for model validation ?
  calibration inevitable

Socio-Economic Analysis Modeling
Division Statistics Canada
3
LifePaths Integration of data

• Historical Demographic Estimates
• Population, Immigration, Emigration, Fertility,
  Mortality
• Census Micro-Data
• Seven Censuses, 1971 to 2001
• Longitudinal Labour Force Survey
• 1976 to 2004 almost 37 million person-months of
  data
• Family History Surveys
• 4 pooled surveys, 1984 to 2001
• Post-secondary Education Administrative Data
• University College Enrolment/Graduate Files
• Other Small and/or One-Off Sources
• Longitudinal Income Tax Records, School Leavers
  Surveys, Survey of Labour Income Dynamics,
  National Population Health Survey,

4
Comparative Advantages of Fertility Data Sources

• Pooled FHS Marital Status Histories
• Coarse Work Histories
• Age-Cohort Profiles Identifiable
• 1991 Census Point-in-time Education
  Point-in-time Student Status
• Spouse Characteristics Modern Fertility
  Patterns
• Large Sample

5
Female Respondents Aged 15-49 by Decade of Birth

• Decade of Birth Pooled FHS 1991 Census
• lt1909 404 0
• 1910-1919 1,976 0
• 1920-1929 2,851 0
• 1930-1939 2,797 0
• 1940-1949 3,819 315,990
• 1950-1959 5,330 466,034
• 1960-1969 5,634 227,175
• 1970-1979 3,332 459,155
• 1980-1989 945 0
• All 27,088 1,468,354

6
Alignment or Calibration?

• Equations tend to be poor predictors of
  micro-data
• Pseudo-R2 of 10 common
• Equations summarize data
• More, Richer Data Better Equations?
• Alignment adjusts equations on-the-fly
• Calibration corrects equations once-and-for-all

7
Calibration allows maximum use of data
8
LifePaths

• A version of LifePaths and supporting software
  Modgen - are available free on the Statistics
  Canada website
• www.statcan.ca/english/spsd/LifePaths.htm
• More information microsimulation_at_statcan.ca

Socio-Economic Analysis Modeling
Division Statistics Canada