Integrated Public Use Microdata Series IPUMSwww.ipums.org Matt Sobek Minnesota Population Center

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

IPUMS-USA Steve Ruggles All existing samples of US census All existing samples of US census Data extraction system 1998 Data extraction system 1998 IPUMS-International IPUMS-Latin America 2004 IPUMS-Latin America 2005 IPUMS-Europe 2005 IPUMS-Europe 2005 NSF Expansion 2005 NSF Expansion World’s largest collection census data 30 samples per year for the next 3 years 30 samples per year for the next 3 years Bob McCaa Bob McCaa Brief History

Datasets in IPUMS

IPUMS Census Sample Holdings and Release Dates

Dark green = disseminating Medium green = data held by IPUMS Light green = negotiating Yellow = not negotiating IPUMS Global Coverage

Selected Variable Availability -- PERSON

Selected Variable Availability -- HOUSEHOLD

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 count of persons by municipality an employment status table by sex from a published census volume

Kenya 1999 Census Questionnaire

Raw Census Microdata from IPUMS

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

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

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

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

Translation Table – Marital Status General Codes

Variable Description: Literacy (International)

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

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 (Simple household)

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 Spouse’sFather’sMother’s IPUMS “Pointer” Variables (Complex household)

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

IPUMS Access Restricted access Scholarly and educational purposes Conditions of use: key is not to redistribute Serious vetting

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

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

Limitations of the Microdata Samples Confidentiality Geography 20,000 population or larger Sensitive variables, swapping, etc Samples Too small to answer some questions

Other Issues and Limitations Not annual Any historical analysis will have gaps Cross-sectional data Not longitudinal Need knowledge of a statistical package User burden Information overload; culturally specific knowledge Very large extracts

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

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

Percent in Labor Force Mexico Costa Rica Ecuador Chile Venezuela Colombia Brazil Married Female Labor Force Participation in Latin America (age 18 to 65)

Percent in Labor Force Latin America United States Married Female Labor Force Participation: Latin America and U.S. (age 18 to 65)

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

Married Female Labor Force Participation: Mexican-born Women, Percent in Labor Force Mexican-born Women in United States Women in Mexico

End