1. Integrated Public Use Microdata Series IPUMSwww.ipums.org

2. IPUMS Overview 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Access 5. Strengths and Limitations 6. Dissemination 1. What is the IPUMS

3. Census Samples in IPUMS-USA

4. Planned 2006-2009

5. Datasets in IPUMS-International

6. IPUMS-International Census Sample Holdings and Release Dates

7. Datasets in IPUMS-CPS

8. What Are Microdata? Individual-level data every record represents a separate person all of their individual characteristics are recorded users must manipulate the data themselves Different from aggregate/summary/tabular data a disability table from www.factfinder.census.gov an occupation table from a published census volume from the library

9. 1930 Census Population Schedule

10. Raw Census Microdata from IPUMS

11. IPUMS Data Structure Household record (shaded) followed by a person record for each member of the household Relationship Age Sex Race Birthplace Mother’s birthplace Occupation For each type of record, columns correspond to specific variables

12. The Advantages of Microdata  Combination of all of a person’s characteristics  Characteristics of everyone with whom a person lived  Freedom to make any table you need  Freedom to make models examining multivariate relationships  Basically, you are only limited by the questions asked in the particular census

13. 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Access 5. Strengths and Limitations 6. Dissemination IPUMS Overview

14. Translation Table – Marital Status China1982Colombia1973Kenya1989Mexico1970U.S.A.1990 (IPUMS-International)

15. Translation Table – Marital Status General Codes

16. Variable Description: Farm Status (USA)

17. Variable Description: Literacy (International)

18. 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Access 5. Strengths and Limitations 6. Dissemination IPUMS Overview

19. PernumRelateAgeSexMarstChborn 1head46malemarriedn/a 2spouse44femalemarried3 3aunt77femalewidow7 4child15femalesingle0 5child13femalesinglen/a 6child11malesinglen/a PernumRelateAgeSexMarstChborn 1head46malemarriedn/a 2spouse44femalemarried3 3aunt77femalewidow7 4child15femalesingle0 5child13femalesinglen/a 6child11malesinglen/a Spouse’s Mother’sFather’s IPUMS “Pointer” Variables Location 2 1 0 0 0 0 0 0 00 0 0 21 1 1 2 2 (Simple household)

20. PernumRelationshipAgeSexMarstChborn 1head53femaleseparated6 2child28malesinglen/a 3child22malesinglen/a 4child21malesinglen/a 5child25femalemarried2 6child-in-law28malemarriedn/a 7grandchild3malesinglen/a 8grandchild1malesinglen/a 9non-relative32femaleseparated2 10non-relative10malesinglen/a 11non-relative5femalesinglen/a Location 0 0 0 0 0 6 5 0 0 0 0 0 0 1 1 1 1 0 5 5 0 9 9 0 0 0 6 6 0 0 0 0 0 Spouse’sFather’sMother’s IPUMS “Pointer” Variables (Complex household)

21. Additional Improvements to the U.S. PUMS  Additional documentation, including all enumeration forms and instructions   Consistent occupation/industry classifications  Consistent metropolitan classifications  Constructed family variables  Missing data allocation   International – pointers for some samples; occupation and industry; missing data in the future

22. 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Access 5. Strengths and Limitations 6. Dissemination IPUMS Overview

23. USA – unrestricted, automated registration IPUMS Access CPS – unrestricted, automated registration International – restricted access Scholarly and educational purposes Conditions of use: key is not to redistribute Serious vetting

24. Economics (36%) Sociology (16%) Demography (12%) Other Academic (19%) Other Non-academic (15%) IPUMS Users 46% students; 23% faculty

25. Other IPUMS-USA Data Sources Querylogic (www.querylogic.com) PDQ (www.pdq.com) Fathom (www.keypress.com/fathom)

26. 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Access 5. Strengths and Limitations 6. Dissemination IPUMS Overview

27. 4 Key Strengths of the Census Microdata Samples National in scope Results not subject to local peculiarities Provide context for local studies More cases than any comparable datasets Enable study of relatively small populations Large Temporal depth Provide historical perspective Microdata Can make your own tabulations Apply multivariate techniques

28. Limitations of the Microdata Samples Geographic detail Confidentiality restrictions Not annual Any historical analysis will have gaps Cross-sectional data Not longitudinal Need knowledge of a statistical package Samples Too small to answer some questions

29. Limitations of the Different IPUMS Data Series IPUMS-USA Geography 1940-present IPUMS-International Varying geography User burden: need to read documentation, information overload IPUMS-CPS Sample size (60 to 200K)

30. Studies that do not need to identify small geographic areas 100,000+ population for USA 1940-present Varies for International: as low as 20,000+ Subjects that are likely to deal with 10,000+ people Varies by sample density Topics where the key census questions were asked in comparable ways across samples Topics that take advantage of the hierarchical structure of the data: co-resident persons Some Characteristics of Good IPUMS Topics

31. IPUMS-International Research Topics Child labor outside the household in Mexico and Colombia Effect of NAFTA on educational attainment and school enrollment by region within Mexico Concentration of mortality within families in Kenya Life course patterns of co-residence among Mexicans in Mexico, Mexicans in the U.S., and Mexican Americans Brain drain from developing countries How language diversity is affected by migration and economic factors

32. 0 5 10 15 20 25 30 35 40 45 50 1960196519701975198019851990199520002005 Percent in Labor Force Mexico Costa Rica Ecuador Chile Venezuela Colombia Brazil Married Female Labor Force Participation in Latin America (age 18 to 65)

33. 0 10 20 30 40 50 60 70 1920193019401950196019701980199020002010 Percent in Labor Force Latin America United States Married Female Labor Force Participation: Latin America and U.S. (age 18 to 65)

34. 0 10 20 30 40 50 60 70 1920193019401950196019701980199020002010 Percent in Labor Force United States Mexico Costa Rica Ecuador Chile Venezuela Colombia Brazil Married Female Labor Force Participation: Latin America and U.S. (age 18 to 65) Compare Latin America to U.S. 40 years ago

35. Married Female Labor Force Participation: Mexican-born Women, 1970-2000 0 10 20 30 40 50 60 70 1970197519801985199019952000 Percent in Labor Force Mexican-born Women in United States Women in Mexico

36. 1. What is the IPUMS 2. Harmonization 3. Additional Data Enhancements 4. Users and Access 5. Strengths and Limitations 6. Dissemination IPUMS Overview