Definition
This variable indicates the First Stage Unit (FSU) serial number. The first stage units (FSU) will be the 2001 census villages (Panchayat wards in case of Kerala) in the rural sector and Urban Frame Survey (UFS) blocks in the urban sector. The ultimate stage units (USU) will be households in both the sectors. In case of large FSUs, one intermediate stage of sampling will be the selection of two hamlet-groups (hgs)/ sub-blocks (sbs) from each rural/ urban FSU.