India - Household Consumer Expenditure, July 2004 - June 2005, NSS 61st Round

Sample Design

Outline of sample design: A stratified multi-stage design has been adopted for the 61st round survey. The first stage units (FSU) were the 2001 census villages in the rural sector and Urban Frame Survey (UFS) blocks in the urban sector. The ultimate stage units (USU) were households in both the sectors. In case of large villages/blocks requiring hamlet-group (hg)/sub-block (sb) formation, one intermediate stage was the selection of two hgs/sbs from each FSU.

Sampling Frame for First Stage Units: For the rural sector, the list of 2001 census villages (panchayat wards for Kerala) constituted the sampling frame. For the urban sector, the list of latest available Urban Frame Survey (UFS) blocks were considered as the sampling frame.

Stratification: Within each district of a State/UT, two basic strata were formed: i) rural stratum comprising of all rural areas of the district and (ii) urban stratum comprising of all the urban areas of the district. However, if there are one or more towns with population 10 lakhs or more as per population census 2001 in a district, each of them also formed a separate basic stratum and the remaining urban areas of the district were considered as another basic stratum. There were 27 towns with population 10 lakhs or more at all-India level as per census 2001.

Sub-stratification:

Rural sector: If ‘r’ be the sample size allocated for a rural stratum, the number of sub-strata formed were ‘r/2’. The villages within a district as per frame were first arranged in ascending order of population. Then sub-strata 1 to ‘r/2’ were demarcated in such a way that each sub-stratum comprised a group of villages of the arranged frame and had more or less equal population.

Urban sector: If ‘u’ be the sample size for a urban stratum, ‘u/2’ number of sub-strata were formed. The towns within a district, except those with population 10 lakhs or more, were first arranged in ascending order of population. Next, UFS blocks of each town were arranged by IV unit no. × block no. in ascending order. From this arranged frame of UFS blocks of all the towns, ‘u/2’ number of sub-strata were formed in such a way that each sub-stratum had more or less equal number of UFS blocks.

For towns with population 10 lakhs or more, the urban blocks were first arranged by IV unit no. × block no. in ascending order. Then ‘u/2’ number of sub-strata were formed in such a way that each sub-stratum had more or less equal number of blocks.

Total sample size (FSUs): 12984 FSUs have been allocated at all-India level on the basis of investigator strength in different States/UTs for central sample and 14104 for state sample.


There was no deviation from the original sampling design.