India - Employment and Unemployment, July 2011- June 2012, NSS 68th Round

The 68th round (July 2011-June 2012) of NSS was earmarked for survey on 'Household Consumer Expenditure' and 'Employment and Unemployment'. The survey covered the whole of the Indian Union except (i) interior villages of Nagaland situated beyond five kilometres of the bus route and (ii) villages in Andaman and Nicobar Islands which remain inaccessible throughout the year. In addition to these, all the sample first stage units of the following areas were casualty in different sub-rounds: in sub-rounds 1, 2,3 and 4. In each of these four sub-rounds equal number of sample villages/ blocks (FSUs) was allotted for survey with a view to ensuring uniform spread of sample FSUs over the entire survey period. Attempt was made to survey each of the FSUs during the sub-round to which it is allotted. Because of the arduous field conditions, this restriction need not be strictly enforced in Andaman and Nicobar Islands, Lakshadweep and rural areas of Arunachal Pradesh and Nagaland.

Sample Design
A stratified multi-stage design has been adopted for the 68th round survey. The first stage units (FSU) was 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) was households in both the sectors. In case of large FSUs, one intermediate stage of sampling was the selection of two hamlet-groups (hgs)/ sub-blocks (sbs) from each rural/ urban FSU.

Selection of the first-stage units: The various steps involved before making the selection of the FSUs are discussed at length in the following few paragraphs before taking up the issue of selection of USUs within FSUs.

Sampling Frame for First Stage Units: For the rural sector, the list of 2001 census villages (Panchayat wards in case of Kerala) constituted the sampling frame. For the urban sector, the list of latest available UFS blocks constituted the sampling frame.

Stratification of the first stage units: Within each district of a State/ UT, two basic strata were formed as follows:
Within each sector of a State/ UT, the respective sample size will be allocated to the different strata/ sub-strata in proportion to the population as per census 2001. Allocations at stratum level were adjusted to multiples of 4 with a minimum sample size of 4. Allocation for each sub-stratum was 4. Equal number of samples were allocated among the four sub-rounds.


Selection of first-stage units: For the rural sector, from each stratum/ sub-stratum, required number 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 urban sector, from each stratum FSUs were selected by using Simple Random Sampling Without Replacement (SRSWOR). Both rural and urban samples were drawn in the form of two independent sub-samples.

Selection of Ultimate Stage Units (USU) within a FSU: The remaining paragraphs of this sub-section outlines the various steps leading to the actual selection of USUs within a FSU.

Criterion for hamlet-group/ sub-block formation: After identification of the boundaries of the FSU, it is to be determined whether listing was done in the whole sample FSU or not. In case the population of the selected FSU is found to be 1200 or more, it should be divided into a suitable number (say, D) of 'hamlet-groups' in the rural sector and 'sub-blocks' in the urban sector by more or less equalising the population as stated below.

approximate present population of the sample FSU no. of hg's/sb's to be formed

less than 1200 (no hamlet-groups/sub-blocks) 1
1200 to 1799 3
1800 to 2399 4
2400 to 2999 5
3000 to 3599 6
…………..and so on

For rural areas of Himachal Pradesh, Sikkim, Uttarakhand (except four districts Dehradun (P), Nainital (P), Hardwar and Udham Singh Nagar), Poonch, Rajouri, Udhampur, Doda, Leh (Ladakh), Kargil districts of Jammu and Kashmir and Idukki district of Kerala, the number of hamlet-groups were formed as follows:

approximate present population of the sample village no. of hg's to be formed

less than 600 (no hamlet-groups) 1
600 to 899 3
900 to 1199 4
1200 to 1499 5
.………..and so on



Formation and selection of hamlet-groups/ sub-blocks: In case hamlet-groups/ sub-blocks are to be formed in the sample FSU, the same should be done by more or less equalizing population.It was ensured that the hamlet-groups/ sub-blocks formed were clearly identifiable in terms of physical landmarks.

Two hamlet-groups (hg)/ sub-blocks (sb) were selected from a large FSU wherever hamlet-groups/ sub-blocks have been formed in the following manner - one hg/ sb with maximum percentage share of population always selected and termed as hg/ sb 1; one more hg/ sb selected from the remaining hg's/ sb's by simple random sampling (SRS) and termed as hg/ sb 2. Listing and selection of the households done independently in the two selected hamlet-groups/ sub-blocks. The FSUs without hg/ sb formation treated as sample hg/ sb number 1. It is to be noted that if more than one hg/ sb have same maximum percentage share of population, the one among them which is listed first in block 4.2 of schedule 0.0 treated as hg/ sb 1.

Listing of households: Having determined the hamlet-groups/ sub-blocks, i.e. area(s) to be considered for listing, the next step is to list all the households (including those found to be temporarily locked after ascertaining the temporariness of locking of households through local enquiry). The hamlet-group/ sub-block with sample hg/ sb number 1 considered for listing first, to be followed by the listing of households within the sample hg/sb number 2.

Formation of second stage strata and allocation of households


Two cut-off points 'A' and 'B' (in Rs.) are determined from NSS 66th round data for each NSS region for urban areas in such a way that top 10% of the population have MPCE more than 'B' and bottom 30% of the population have MPCE less than A. The values of A and B for each NSS Region have been given in Chapter Two.


For both Schedule 1.0 and Schedule 10, households listed in the selected FSU/ hamlet-group/ sub-block stratified into three second stage strata (SSS). Composition of the SSS and number of households to be surveyed from different SSS for each of the three schedules of enquiry namely, Schedule 1.0 (Type 1), Schedule 1.0 (Type 2) and Schedule 10 will be as follows:

SSS composition of SSS number of households to be surveyed
FSU without hg/sb formation FSU with hg/sb formation (for each hg/sb)
Rural
SSS 1: relatively affluent households 2 1
SSS 2: of the remaining, households having principal earning from non- agricultural activity 4 2
SSS 3: other households 2 1
Urban
SSS 1: households having MPCE of top 10% of urban population (MPCE > B) 2 1
SSS 2: households having MPCE of middle 60% of urban population (A = MPCE = B) 4 2
SSS 3: households having MPCE of bottom 30% of urban population (MPCE < A) 2 1

The above table provides the plan of allocation of the sample household in the respective SSS. However, there can be situations in the selected FSUs both in rural and urban sectors where adequate number of households is not available for required allocation. In such situation, the selection of household for the SSS is compensated from the other SSS. This is done by adopting specified procedure. To meet the shortfall of households in one SSS compensation can be made from other SSSs. The details of the compensation rules are given in the Chapter two dealing with household Listing Schedule 0.0.

Selection of households: From each SSS the sample households for each of the schedules selected by SRSWOR. If a household is selected for more than one schedule, only one schedule canvassed in that household in the priority order of Schedule 1.0 (Type 1), Schedule 1.0 (Type 2) and Schedule 10 and in that case the household replaced for the other schedule. If a household is selected for Schedule 1.0 (Type 1) it was not be selected for Schedule 1.0 (Type 2) or Schedule 10. Similarly, if a household is not selected for Schedule 1.0 (Type 1) but selected for Schedule 1.0 (Type 2) it not be selected for Schedule 10.


For all subround weights (or multipliers) are given at the end of each record
from 133rd byte onwards. The weights (multipliers) are
Sub-sample-wise, details of which are as given below :
(For description of subsample, please see Instructions
Manual for field staff, Vol-I)


Use of subsample-wise weights (all-subround multipliers)
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For generating subsample-wise estimates based on data of all
subrounds taken together, either Subsample-1 households or
Subsample-2 households are to be considered at one time.
Subsample code is available in the data file.
(Please see layout of data).

Apply final weight (or all-subround multipliers) as follows :

final weight = MLT/100, if NSS=NSC
= MLT/200 otherwise.

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Use of subsample-wise weights (subround multipliers)
----------------------------------------------------------------

For generating subsample-wise estimates based on data of a particular
subround, either Subsample-1 households or Subsample-2 households
are to be considered at one time. Subsample code is available in the
data file. (Please see layout of data).

Apply weight (or subround multipliers) as follows :

weight = MLT_SR/100, if NSS_SR=NSC_SR
= MLT_SR/200 otherwise.