1. MICS Data Processing Workshop
Adding the Wealth Index and GPS Data

2. Secondary Data Processing Flow
Export Data from CSPRO
Import Data into SPSS
Recode Variables
Add the Wealth Index and GPS Data
Run Tables

3. Sampling
The probability of selecting a household for MICS interviews was not equal across all of Popstan
In North region
28 households were selected per 10,000
In West Region
5 households were selected per 10,000
Overall
10 households were selected per 10,000

4. Sample Weights
Sample weights are used to adjust the sample to produce accurate estimates for the whole country
Sample weights are the inverse of the relative probabilities of selection
For example, the weights for North and West region
North region 10/28 = 0.36
West region 10/5 = 2
Weights should always be used when tabulating

5. Sample Weights Objects
WEIGHTS.XLS
spreadsheet that calculates weights
WEIGHTS_TABLE.SPS
SPSS program that provides input data for spreadsheet
WEIGHTS.SPS
SPSS program that defines structure of spreadsheet’s output
WEIGHTS_MERGE.SPS
SPSS program that merges weights onto the MICS data files

6. Steps in Adding Weights
1. Update weights.xls to have one row per strata/cluster
2. Add sampling information to weights.xls
3. Adapt strata definitions in weights_table.sps
4. Execute weights_table.sps program
5. Copy resulting table’s contents into “Calculations” sheet of weights.xls
6. Save “Output” sheet of weights.xls as weights.csv in directory c:\mics\weights
7. Execute weights_merge.sps program

7. Step 1: Updating weights.xls
Spreadsheet has one row per cluster
Adjust the number of rows in “Calculations” to reflect the number of clusters in your survey
Do so by copying and pasting internal rows
Check that the totals cells have the correct ranges
Adjust the number of rows in “Output”
Check that data in “Output” is correct

8. Step 2: Adding Sampling Info
Open weights.xls
Complete the “stratum sampling fraction” column
Complete the “cluster sampling fraction” column
Enter 1 if your weights don’t vary by cluster within a stratum
Otherwise enter the cluster sampling fraction

9. Step 3: Defining Strata Your survey has sampling strata. Examples:
all combinations of area (HH6) and region (HH7)
region
Lines 3-10 of weights_table.sps define the standard survey’s strata
Updates these statements to reflect the definition of strata in your country

10. Step 4: Executing weights_table.sps
Open weights_table.sps in SPSS
Select Run--->all
Check output for error messages
Examine output table

11. Step 5: Copying Output Double-click inside the table to open it
Select the household results
Paste them in the “Calculations” sheet of weights.xls
Repeat for the women and children results
Save weights.xls

12. Step 6: Saving the Output Sheet
Click on the “output” tab in the weights.xls spreadsheet
Select File ---> Save As
Navigate to the directory c:\mics\weights
Change the “save as type:” to “CSV (Comma delimited)(*.csv)”
file name should automatically change to weights.csv
Click the save button

13. Step 7: Merging Weights into SPSS
Open weights_merge.sps in SPSS
Select Run ---> all
Check output for error messages
Open each data file—HH, HL, WM and CH — and check that weights were correctly added

14. Useful Merging Commands
get file = ‘filename.sav’.
sort cases by varlist.
save outfile = ‘filename.sav’
[/keep varlist]
[/drop varlist]
[/rename = (BI1 = BR1) (BI2 = BR2)].
erase file = ‘filename.sav’.

15. MATCH FILES Command match files /file = * /file = ‘filename.sav’
/by varlist.
/table = ‘filename.sav’

16. WEIGHTS_MERGE.SPS Source Files: c:\mics\spss\weights.sav
Destination Files: hh.sav, hl.sav, wm.sav, ch.sav
Match By: HH1
Variables Added: xxweight where
xx is HH, WM or CH

17. The Wealth Index
The MICS wealth index is an attempt to measure the socio-economic status of households
The analysis section of this process will be done at the 3rd workshop
The goal today is to discuss the programs and how they work

18. Wealth Index Programs
There are two program related to the wealth index
WEALTH.SPS
This program calculates the wealth index
WEALTH_MERGE.SPS
This program adds the wealth index to the SPSS data files

19. WEALTH.SPS Calculates a wealth index using factor analysis Inputs:
dichotomous variables related to household/individual assets
Outputs:
wlthscor - a wealth index score for each household
wlthind5 - a wealth quintile for each household

20. A Recoding Example
Code below creates variable with value 1 if household owns a car, value 0 otherwise
compute car = 0.
if (hc10e = 1) car = 1.
variable label car 'Household member owns: car/truck'.
value label car 0 'No' 1 'Yes'.

21. The Rest of the Program The factor statement The compute statement
creates wealth index score
The compute statement
generates household member weights
The rank statement
creates wealth quintiles
The save outfile statement
saves wealth variables in wealth.sav file

22. WEALTH_MERGE.SPS Source Files: c:\mics\spss\wealth.sav
Destination Files: hh.sav, hl.sav, wm.sav, ch.sav
Match By: HH1, HH2
Variables Added: wlthscor, wlthind5

23. GPS Readings
Some countries will take GPS readings during their MICS survey
These readings allow researchers to merge diverse data sets using a cluster’s location
Data sets that can be linked to the MICS data
Climate data
Agricultural data

24. The GPS Form

25. GPS Programs GPS.DIC GPSENTRY.ENT GPS.SPS GPS_MERGE.SPS
CSPRO dictionary
GPSENTRY.ENT
CSPRO data entry application
GPS.SPS
SPSS version of GPS.DIC
GPS_MERGE.SPS
reads in GPS data and merges it onto SPSS data files

26. GPS_MERGE.SPS Source Files: c:\mics\spss\gps.dat
Destination Files: hh.sav, hl.sav, wm.sav, ch.sav
Match By: HH1
Variables Added: all variables on GPS form