What’s the unique id for me to identify household if I want to merge ASEC data along the time.

Merge/match consecutive years of ASEC datasets (longitudinal design)

A unique id, for purposes of linking households between ASEC samples, can be created by combining HRHHID and HRHHID2. Note that your match rate will be under fifty-percent for any given two-year period. This is because only half of the sample is eligible to appear in both years of any two consecutive years. Also, households and persons can drop out of the survey (due to relocation, refusing to participate, etc.).