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

4. Creating an extract4. Creating an extract

»Password protected: to make and retrieve extractsPassword protected: to make and retrieve extracts

»Licensed researcher selects: Licensed researcher selects: »Countries, Countries, »Censuses,Censuses,»Cases/sub-populations, Cases/sub-populations, »Variables, and Variables, and »Sample densitiesSample densities

»Extract engine queues request, generates extractExtract engine queues request, generates extract

»Researcher retrieves extract via web with SSL 128-bit Researcher retrieves extract via web with SSL 128-bit encryption and analyzes using own wares (soft/hard/wet)encryption and analyzes using own wares (soft/hard/wet)

»NONO: CDs, original codes, or complete datasets: CDs, original codes, or complete datasets

2b. “Create an Extract”2b. “Create an Extract”

4 steps in creating an extract4 steps in creating an extract(the database is huge—the key is “extracts”):(the database is huge—the key is “extracts”):

0. Login with your email and password0. Login with your email and password

1. Select countries & 1. Select countries & census yearscensus years

2. Select variables2. Select variables

““case selection”case selection”(Selection of cases (Selection of cases

(subpoblations)(subpoblations)

3. Selecting cases3. Selecting cases

4. Downloading the extract4. Downloading the extract

Analyze with your preferred Analyze with your preferred statistical packagestatistical package

» ““Un-ZIP” with “WinZIP; careful with Windows Un-ZIP” with “WinZIP; careful with Windows foldersfolders

» Apply weights (WTPER; note 4 decimals!): Apply weights (WTPER; note 4 decimals!): » Essential for countries like Brazil, Mexico, Spain, USA, etc. but Essential for countries like Brazil, Mexico, Spain, USA, etc. but

not Greecenot Greece

» Expansion factors: households (WTHH) or persons (WTPER)Expansion factors: households (WTHH) or persons (WTPER)

» Derivation of weights: WT=WT/mean(WT, each sample), HH or Derivation of weights: WT=WT/mean(WT, each sample), HH or PERPER

*SPSS Instructions for expansion factors.*SPSS Instructions for expansion factors.COMPUTE wtper = wtper/10000. [Note 4 decimals!!!!!]COMPUTE wtper = wtper/10000. [Note 4 decimals!!!!!]WEIGHT BY wtper.WEIGHT BY wtper.

*….. To weight cases, yet maintain the actual number of cases in *….. To weight cases, yet maintain the actual number of cases in the sample, considerthe sample, consider, for example, for example Brazil: Brazil:COMPUTE wtcensus=census.COMPUTE wtcensus=census.RECODE wtcensus (96 97 98 = 20) (99=17.24) (00=16.67) [“96” RECODE wtcensus (96 97 98 = 20) (99=17.24) (00=16.67) [“96” = 1960, 97=1970].= 1960, 97=1970].COMPUTE wtper=wtper/wtcensus.COMPUTE wtper=wtper/wtcensus.WEIGHT BY wtper.WEIGHT BY wtper.