1. IPUMS Extract Exercise
Lisa Neidert
Poverty/American Community Survey Workshop
June 23-27, 2008

2. Purpose of extracting data
Modeling
Regressions, etc.
Recodes
In familiar statistical package

3. IPUMS Same data we have used with PDQ-Explore Concatenated file
Can select one year or many
Final product is:
Data (compressed)
Codebook
Set-up statements

4. Strategy Do simple extract Download
Uncompress data
Modify set-up statement
Produce means and regression in statistical package of choice
SAS, SPSS, stata
Go back and produce ‘real’ extract
Take time choosing variables

5. Variables http://usa.ipums.org/usa/VariableGroups.do
Variables arranged by Subject
General version
Detailed version

6. Variables included in my extract
hhwt (default)
perwt (default)
age [25-54]
sex [males]
race [white, black]
incearn
poverty

7. Sample selections
Exclude incearn < 1

8. Recodes L_Earn = Log(Incearn) White (dummy variable) A2 = Age*Age
Interaction terms (with white)
W_Age
W_Age2

9. Download/Unzip data
If zipped file does not have an icon associated with it, your PC is missing software
Solution
Use my PC
Copy to gift flash drive

10. Modify program SAS wants you to identify:
Work area
Data location
Desktop location as a path is:
'c:\Documents and Settings\lisan\Desktop’
'c:\Documents and Settings\lisan\ Desktop\lisan_umich_edu_078.dat'