India - Household Consumer Expenditure Type-1, July 2009 - June 2010, NSS 66th Round

Sample design
Outline of sample design: A stratified multi-stage design was adopted for the 66th round survey. The first stage units (FSUs) were the 2001 Census villages (Panchayat wards in case of Kerala) in the rural sector and Urban Frame Survey (UFS) blocks in the urban sector. In addition, two non-UFS towns of Leh and Kargil of Jammu & Kashmir were also treated as FSUs in the urban sector. The ultimate stage units (USU) were households in both the sectors. In case of large FSUs, one intermediate stage of sampling was the selection of two hamlet-groups (hgs)/subblocks (sbs) from each rural/urban FSU.

Sampling frame for first stage units:
For the rural sector, the list of 2001 Census villages (henceforth the term 'village' will mean Panchayat wards for Kerala) constituted the sampling frame. For the urban sector, the list of latest available UFS blocks was considered as the sampling frame. For non-UFS towns, the frame consisted of the individual towns (only two towns, viz., Leh & Kargil constituted this frame).

Stratification:
Within each district of a State/UT, generally speaking, two basic strata were formed: i) rural stratum comprising all rural areas of the district and (ii) urban stratum comprising all urban areas of the district. However, within the urban areas of a district, wherever there were one or more towns with population 10 lakhs or more as per Census 2001 in a district, each of these formed a separate basic stratum and the remaining urban areas of the district were considered as another basic stratum. Sub-stratification: Each rural stratum was divided into 2 sub-strata as follows: sub-stratum 1: all villages with proportion of child workers (p) >2P (where P is the average proportion of child workers for the State/UT as per Census 2001) sub-stratum 2: remaining villages

Total sample size (FSUs):
At all-India level, 12784 FSUs were allocated to the Central sample and 15132 FSUs to the State sample. Further, the data of 24 State sample FSUs of Leh and Kargil districts of J&K surveyed by DES, J&K, were included in the Central sample.

Allocation of total sample to States and UTs:
The total number of sample FSUs was allocated to the States and UTs in proportion to population as per Census 2001 subject to a minimum sample allocation to each State/UT, and subject to resource availability in terms of field investigators.

Allocation of State/UT level sample to rural and urban sectors:
State/UT level sample size was allocated between the two sectors in proportion to population as per Census 2001 with double weightage to urban sector, subject to the restriction that the urban sample size for bigger States like Maharashtra, Tamil Nadu, etc. should not exceed the rural sample size. A minimum of 16 FSUs (to the extent possible) was allocated to each State/UT separately for rural and urban areas. Further, the State-level allocations for both rural and urban sectors were adjusted marginally in a few cases to ensure that each stratum/sub-stratum got a minimum allocation of 4 FSUs.

Allocation to strata/sub-strata:
Within each sector of a State/UT, the sample size was allocated to different strata/sub-strata in proportion to population as per Census 2001. Allocations at stratum/sub-stratum level were adjusted to multiples of 4 with a minimum sample size of 4 and equal-sized samples were allocated to the four sub-rounds.

Selection of FSUs:
For the rural sector, from each stratum/sub-stratum, the required numbers of sample villages were selected by probability proportional to size with replacement (PPSWR), size being the population of the village as per Census 2001. For the urban sector, FSUs were selected from each stratum using Simple Random Sampling Without Replacement (SRSWOR). Both rural and urban samples were drawn in the form of two independent sub-samples.


Formation and selection of hamlet-groups/sub-blocks:
Selected FSUs with approximate population 1200 or more were divided into a suitable number of geographically compact 'hamlet-groups' (having more or less equal population) in the rural sector and 'sub-blocks' in the urban sector .

Selection of hamlet-groups/sub-blocks:
Hamlet-groups (hg)/sub-blocks (sb) were selected from FSUs where hamlet-groups/sub-blocks were formed, two in the following manner. The hg/sb with maximum percentage share of population was always selected and termed hg/sb 1;one more hg/sb was selected from the remaining hg’s/sb’s by simple random sampling (SRS) and termed hg/sb 2. Listing and selection of the households was done independently in the two selected hamlet-groups/sub-blocks.