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

MICS Data Processing Workshop

Adding the Wealth Index and GPS Data

Secondary Data Processing Flow

Export Data from CSPRO

Import Data into SPSS

Recode Variables

Add the Wealth Index and GPS Data

Run Tables

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

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

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

Steps in Adding Weights

1. Update weights.xls to have one row per strata/cluster

2. Add sampling information to weights.xls3. Adapt strata definitions in weights_table.sps4. Execute weights_table.sps program5. Copy resulting table’s contents into “Calculations”

sheet of weights.xls6. Save “Output” sheet of weights.xls as weights.csv in

directory c:\mics\weights7. Execute weights_merge.sps program

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

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

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

Step 4: Executing weights_table.sps

Open weights_table.sps in SPSS Select Run--->all Check output for error messages Examine output table

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

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

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

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’.

MATCH FILES Command

match files/file = *

/file = ‘filename.sav’ /by varlist.

match files/file = *

/table = ‘filename.sav’ /by varlist.

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 wherexx is HH, WM or CH

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

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

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

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'.

The Rest of the Program

The factor 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

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

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

The GPS Form

GEOGRAPHIC POSITIONING SYSTEM FORM GP

GP1. Cluster number:___ ___ ___

GP2. Area:Urban........................................... 1Rural ............................................ 2

GP3. Region:Region 1 ...................................... 1Region 2 ...................................... 2Region 3 ...................................... 3Region 4 ...................................... 4

GP4. Operator name and number:

Name ___ ___

GP5. Day/Month/Year of measurement: ___ ___ / ___ ___ / ___ ___ ___ ___

GP6. Waypoint name:___ ___ ___ ___ ___ ___

N/S/E/W Degrees Decimal degrees

GP7. Latitude: N S ___ ___ . ___ ___ ___ ___ ___

GP8. Longitude: E W ___ ___ ___ . ___ ___ ___ ___ ___

GPS Programs

GPS.DIC– 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

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