ID Variables

Two systems of ID variables are employed in CHNS data files: the original system used in surveyes before 2004 files, and a revised system used thereafter. All old IDs have been changed to new IDs in all files except those used in constructed income files.

Household ID (HHID)

HHID is a 9-digit numeric variable which uniquely identifies each household, which was 7-digit in old cross-sectional files. Variables T1-T5 (documented in the questionnaire) were concatenated to form HHID. Each HHID value represents 1 household. When the unit of analysis for a file/table is household, 1 HHID = 1 row = 1 household = 1 observation. Observations in these files are sorted by HHID and survey year (Wave). Thus the key sort variables for these files are HHID and Wave.

Individual ID (LINE)

LINE is a 3-digit numeric variable which uniquely identifies each individual member of a household, which was 2-digit in old cross-sectional files. Each LINE value represents 1 individual. When the unit of analysis for a file/table is individual, 1 LINE = 1 row = 1 individual = 1 observation. Observations in these files are sorted by HHID, LINE, and Wave, i.e., the key sort variables are HHID, LINE, and Wave.

Community ID (COMMID)

A third ID variable, COMMID, is a 6-digit numeric variable which uniquely identifies each community. Variables T1-T4 were concatenated to create COMMID. Each COMMID value represents 1 community. When the unit of analysis for a file is community, 1 COMMID = 1 community = 1 observation. Observations in these files are sorted by COMMID and Wave, i.e., the key sort variables are COMMID and Wave. Although COMMID is not required for most file merges, this variable is included on all data sets in order to facilitate merges with community-level files.

When the unit of analysis is something other than individual, household or community (e.g., job, livestock type, food item, health facility), a variable which identifies this unit is included on the file (e.g., JOB, F11, FOODCODE, Q1). For the files/tables where job is the unit of analysis, for example, each value of the variable JOB represents 1 occupation. That is, 1 JOB = 1 row = 1 occupation = 1 observation. Observations in these files are sorted by HHID, LINE, and JOB, i.e., the key sort variables are HHID, LINE, and JOB.

Survey Year (WAVE)

WAVE is a 4-digit numeric variable which identifies survey year (i.e, 1989, 1991, 1993, 1997, 2000, 2004, and 2006). This variable was used in master longitudinal files only.