# Presentation: 688663

##  IPUMS-International

- Steven Ruggles

- Minnesota Population Center

## What is IPUMS-International? 

- The IPUMS-International project is creating an integrated global database of over 150 censuses from at least 44 countries.
- It will be the world’s largest public-use population database, with multiple samples from each country enabling analyses across time and space.
- The microdata and accompanying documentation will be freely available for scholarly and educational research through a web-based data dissemination system.

## The Problem

- A vast body of raw census microdata covering much of the world over the past four decades survives in machine-readable form.
- In most countries, these census microdata are either unavailable to researchers or difficult to obtain.
- These data are at constant risk of destruction because of technological obsolescence, physical aging of computer tapes, and loss of institutional memory and documentation

## Why it matters

- In the few countries where census microdata are readily available to researchers, they have become an indispensable part of social science infrastructure.
- In the journal *Demography*, the leading U.S. journal of population, census microdata are used three times as often as any other source for studies of the U.S. or Canada.
- No alternate source offers comparable sample sizes, chronological depth, or widespread availability across countries.

## Advantages of Census Microdata Samples

**Notes:**
To summarize.....

## Cross-National Harmonization and Open Access:National Academy of Science recommendations

- “National and international funding agencies should establish mechanisms that facilitate the harmonization of data collected in different countries.”
- “Cross national studies conducted within a framework of comparable measurement can be a substantially more useful tool for policy analysis than studies of single countries.”
- “The scientific community, broadly construed, should have widespread and unconstrained access to the data.”
-      Source: *Preparing for an Aging World: The Case for Cross-National Research* (National Academy, 2001)

## The Model: IPUMS-USA

- Project to harmonize U.S. Census microdata for the period 1850-2000
- 1992-1995: NSF-funded IPUMS project harmonized samples using composite codes, documented comparability; 250,000 transformations, 3,000 pages of printed documentation
- 1995-1999: Another NSF project funded an online data access system with integrated hypertext documentation

## Success of IPUMS-USA

- 	User friendly access, harmonized codes, and integrated comprehensive hypertext documentation led to flood of historical census-based research:
- 12,000 users, 75,000 custom data extracts
- Currently distributing an average of 638 MB/hr, 24/7
- 1,300 publications and working papers
- IPUMS-based research is concentrated in the top U.S. journals: the most common venues are *Demography, American Economic Review, Journal of Political Economy, American Sociological Review, Social Forces, *and *Quarterly Review of Economics*

## IPUMS-International

- After 1960, most censuses around the world were tabulated by computer
- McCaa decided that IPUMS model should be applied to other countries
- Began with a project for Columbia, then in 1999 NSF Infrastructure grant to add six more countries
- 2005-2009: new HSD grant to increase database to 44 countries
- NICHD is also assisting with funding

## IPUMS-International samples: First release

**Notes:**
These are the samples that are currently available.  
Within the next few years we will add quite a few more
--Larger 2000 sample will be available later this year
--1930 will be available in 2005
--1890 is gone, but we’re going to make a “synthetic” one
--1880 100% will be available soon
--1850 Slave sample is in the works
--there has even been talk of extending the series back to 1790

## IPUMS-International Users

- Prospective users must sign confidentiality agreement and provide an abstract explaining need for the data
- Through 9/1/05 we had 980 applicants to use the database, of which 582 were approved (59 percent)
- Users represent 40 countries and 250 institutions, including many international organizations (e.g., ILO, WHO, World Bank, Inter-American Development Fund)

## Early results

- National Academy of Sciences panel (2005) used data from Colombia, Kenya, Mexico, and Vietnam to analyze changing outcomes such as schooling, work, fertility, and marriage as a function of age, gender, and household characteristics.

## Early results

- Cynthia Feliciano (2005) compared the education of immigrants to the United States with those who remained behind to understand patterns of selectivity

## Other topics include:

- Changing living arrangements of the aged
- Concentration of mortality within families
- Impact of rainfall on health and economic welfare
- Female labor-force participation and educational attainment
- Regional inequality differentials
- Brain drain from developing countries
- Effects of emigration on labor markets
- Relationship between divorce and family composition
- Relationship between disease factors and education
- Relationship between educational attainment and cohort size.
- Effect of NAFTA on educational attainment and school enrollment by region within Mexico

## Most users request multiple countries

- IPUMS-International users
- (percent distribution)

| 1 country | 39 |
| --- | --- |
| 2 countries | 24 |
| 3 countries | 10 |
| 4 countries | 6 |
| 5-8 countries | 20 |

## IPUMS-International Tasks

*Inventory and preservation* of data and documentation
*Processing*
*Documentation *(especially comparability)
*Dissemination*—obtain licenses that allow us to disseminate data for educational and scholarly use, and set up secure web-based dissemination system

## IPUMS-International Tasks

*Inventory and preservation* of data and documentation
*Processing*
*Documentation *(especially comparability)
*Dissemination*—obtain licenses that allow us to disseminate data for educational and scholarly use, and set up secure web-based dissemination system

## IPUMS-International Preservation Initiatives

- UN Demographic Center for Latin America (CELADE, Santiago, Chile)~3000 microdata tapes recovered

- and metadata (documentation)

## Status of Data Acquisition

- dark green = disseminating
- medium green = data received
- light green = negotiating

## Current IPUMS-International Partners

**Current funding for 44 countries by 2009**

**Next data release late spring 2006**

## Current IPUMS-International Partners

**Current funding for 44 countries by 2009**

**Next data release late spring 2006**

## IPUMS-International Tasks

*Inventory and preservation* of data and documentation
*Processing*
*Documentation *(especially comparability)
*Dissemination*—obtain licenses that allow us to disseminate data for educational and scholarly use, and set up secure web-based dissemination system

## Processing

- Standardize format
- Correct format errors
- Draw samples
- Add confidentiality protections
- Harmonize codes
- Edit and allocate missing or inconsistent data
- Add standard constructed variables

## Constructed Variables: 

| Pernum | Relationship | Age | Sex | Marst | Chborn |
| --- | --- | --- | --- | --- | --- |
| 1 | head | 53 | female | separated | 6 |
| 2 | child | 28 | male | single | n/a |
| 3 | child | 22 | male | single | n/a |
| 4 | child | 21 | male | single | n/a |
| 5 | child | 25 | female | married | 2 |
| 6 | child-in-law | 28 | male | married | n/a |
| 7 | grandchild | 3 | male | single | n/a |
| 8 | grandchild | 1 | male | single | n/a |
| 9 | non-relative | 32 | female | separated | 2 |
| 10 | non-relative | 10 | male | single | n/a |
| 11 | non-relative | 5 | female | single | n/a |

| Location |
| --- |
|   |
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|   |

| Location |
| --- |
|   |
|   |
|   |
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|   |
|   |
|   |
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|   |

| Location |
| --- |
|   |
|   |
|   |
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|   |
|   |
|   |
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|   |
|   |

**0**

**0**

**0**

**0**

**0**

**6**

**5**

**0**

**0**

**0**

**0**

**0**

**0**

**0**

**5**

**5**

**0**

**9**

**9**

**0**

**0**

**0**

**6**

**6**

**0**

**0**

**0**

**0**

**0**

**Spouse’s**

**Father’s**

**Mother’s**

- Constructed Variables:
- IPUMS Family Interrelationship Pointers

## IPUMS-International Tasks

*Inventory and preservation* of data and documentation
*Processing*
*Documentation *(especially comparability)
*Dissemination*—obtain licenses that allow us to disseminate data for educational and scholarly use, and set up secure web-based dissemination system

## Documentation

- Translate codebooks, enumeration forms, and enumeration instructions into English
- Standardize format and add xml tags
- Write documentation identifying comparability problems across countries, and within countries, across time periods
- Assemble and scan ancillary* *documentation (e.g. census maps, post-enumeration survey results, and additional information on post-enumeration processing).

## Variable Description: Literacy  (International)

## IPUMS-International Tasks

*Inventory and preservation* of data and documentation
*Processing*
*Documentation *(especially comparability)
*Dissemination*—obtain licenses that allow us to disseminate data for educational and scholarly use, and set up secure web-based dissemination system

## Dissemination

- Uniform perpetual agreements with national statistical agencies allows us to disseminate anonymized microdata to researchers who agree to a web-based confidentiality agreement
- MPC staff assess research proposals for feasibility
- Disputes with agencies, if they arise, will be settled by the International Court of Arbitration in Paris
- Data dissemination occurs exclusively through the IPUMS-International web-based data access system

## Slide 30