IPUMS-International Disseminating Census Microdata

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4. Creating an Extract (9 slides)
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4. Creating an extract

• Password protected to make and retrieve
  extracts
• Licensed researcher selects
• Countries,
• Censuses,
• Cases/sub-populations,
• Variables, and
• Sample densities
• Extract engine queues request, generates extract
• Researcher retrieves extract via web with SSL
  128-bit encryption and analyzes using own wares
  (soft/hard/wet)
• NO CDs, original codes, or complete datasets

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2b. Create an Extract
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4 steps in creating an extract(the database is
hugethe key is extracts) 0. Login with your
email and password
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1. Select countries census years
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2. Select variables
case selection(Selection of cases
(subpoblations)
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3. Selecting cases
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4. Downloading the extract
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Analyze with your preferred statistical package

• Un-ZIP with WinZIP careful with Windows
  folders
• Apply weights (WTPER note 4 decimals!)
• Essential for countries like Brazil, Mexico,
  Spain, USA, etc. but not Greece
• Expansion factors households (WTHH) or persons
  (WTPER)
• Derivation of weights WTWT/mean(WT, each
  sample), HH or PER

SPSS Instructions for expansion factors.COMPUTE
wtper wtper/10000. Note 4
decimals!!!!!WEIGHT BY wtper.
.. To weight cases, yet maintain the actual
number of cases in the sample, consider, for
example BrazilCOMPUTE wtcensuscensus.RECODE
wtcensus (96 97 98 20) (9917.24) (0016.67)
96 1960, 971970.COMPUTE
wtperwtper/wtcensus.WEIGHT BY wtper.