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.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

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. /table = ‘filename.sav’

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

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 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

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

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

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