National Sample Survey Office (NSSO)
Statistical System In India
Ministry of Statistics and Programme Implementation
(MoS&PI)
MOS&PI has two Wings
I. Statistics Wing - National Statistical Organization (NSO)


Central Statistics Office (CSO)
National Sample Survey Office (NSSO)
II. Programme Implementation Wing
Statistical System In India
• Central Statistical Office (CSO): The main
responsibility assigned to the CSO is to bring about
coordination of statistical activities among various
statistical agencies in the Central Government and of
Statistical Bureaus of State Governments, which were
set up for similar coordination of activities of statistical
agencies at the State level.
• National Sample Survey Office (NSSO): The main
responsibility assigned to the NSSO is to collect data on
varied Socio-Economic subjects through nation-wide
sample surveys to create and update data base.
National Sample Survey Office (NSSO)
• The Directorate of National Sample Survey (NSS) came
into being in 1950 to collect information through sample
surveys on a variety of socio-economic aspects.
• The Directorate of NSS was assigned the job of
conducting the field work.
• The work relating to finalisation of sampling design,
schedules of enquiries, writing of instructions, training of
field staff, processing of data and writing of reports was
all entrusted to the Indian Statistical Institute.
National Sample Survey Office (NSSO)
• In March 1970, the Directorate of NSS was reorganised
and all aspects of its work were brought under a single
government organization called National Sample Survey
Organisation (NSSO) under the overall technical
guidance of Governing Council.
• After the formation of National Statistical Commission
(NSC) on 01.06.2005, the Governing Council of NSSO
was dissolved and its work was taken over by NSC.
NSC constitution
• Chairman: Eminent statistician or social scientist.
• Part time members: 4 part time members having
experience in
(i) Economic Statistics.,
(ii) Social and Environment Statistics.,
(iii) Statistical Operations such as Census/ Surveys
• The Secretary, Planning commission (ex-officio
member)
• CSI.
THE PRESENT STRUCTURE
Ministry of Statistics&
Programme Implementation
National Statistical
Commission
NSSO
SDRD
FOD
DPD
CPD
National Sample Survey Office
Basic Objective:
Collection of data on varied Socio-Economic subjects
through nation-wide sample surveys to create and
update data base for use in:
-Policy formulation
-Programme implementation
-Programme evaluation
-Research & public debate and
-Economic & administrative decisions for national
development.
Organisational Structure
• The NSSO is headed by the DG & CEO.
• It is the largest survey organization of its kind with staff strength of
about 5288 comprising 269 group A officers and 5019 other officials.
• The organisation has four divisions:
– Survey Design and Research Division (SDRD)
– Field Operations Division (FOD)
– Data Processing Division (DPD)
– Coordination & Publication Division (CPD)
(Earlier called Economic Analysis Division)
NSC and National Sample Surveys (NSS)
• The NSSO functions under the overall guidance of the NSC
and the Working groups constituted by it for each Round of
S.E. surveys.
• The NSC decides
– Short and long term programmes including subjects to be
covered and periodicity
– Methodological improvements in conduct of surveys
• Approves sample design, concepts and definitions,
questionnaires, estimation procedure, tabulation plan, etc.
• Approves studies for improving survey methodology, data
collection, processing and dissemination and other issues .
• Approves the survey reports for release
• Constitute Expert Groups for any specific technical issue, if
necessary
Schedule of Surveys

Ten Year Cycle
 Consumer Expenditure and
Employment & Unemployment
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Twice
 Social Consumption (health, education etc.)
(generally 6 month survey)
-
Twice
 Un-organised Manufacturing
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Twice
 Services Sector
-
Twice
-
Once
 Land & Livestock holdings
and Debt & Investment
 Open Round
-
Two years (For other surveys on demand)
Survey Design And Research Division (SDRD)
Located at Kolkata and headed by Addl. Director General
Major Functions
Formulation of sampling design, concepts and definitions
Drawing of survey schedules
Instruction Manuals for field work
Finalisation of Sample List
Scrutiny and validation instructions i.e. FSP, PDES, CSP, HOWLER Pts. etc.
Checking of Multipliers, draft tables
Formulation of Tabulation plan
Drawing up of Estimation Procedure
Finalisation of survey results & Preparation of key reports
Undertaking studies for the improvement of survey methodology
Publication and distribution/ sale of NSS reports,
Providing technical guidance on sampling techniques to various official
agencies, etc.
• Secretarial assistance to the Working Group on NSS surveys
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Field Operations Division (FOD) of NSSO
Hqrs. at New Delhi and Faridabad and headed by an
Addl. Director General.
The biggest Division of NSSO having a network of 175
offices spread throughout the length and breadth of the
country at 3-levels, viz.:

6 Zonal Offices
 49 Regional Offices
 118 Sub-regional Offices
Responsible for carrying out the field work of not only
the Socio-economic surveys but also for other surveys.
Activities of FOD
Besides carrying out the field work of Socioeconomic surveys, the FOD is also responsible for:
Carrying out the field work of Annual Survey of
Industries (ASI) on behalf of CSO;
Carrying out the supervision of agricultural surveys
conducted by State Agricultural Statistical Authorities
(SASA), on area enumeration and crop cutting
experiments;
Collection of Price Data for Consumer Price Index
(Urban) from Urban Centers, on behalf of CSO;
Collection of price data from rural centers for CPI for
Agricultural/ Rural Labourers compiled by Labour
Bureau; and
Carrying out the Urban Frame Survey (UFS), for a
frame for urban areas for Socio-economic surveys.
Field Problems in SE Survey
Length of schedules resulting in informant/
investigator fatigue
Arduous field conditions
Informants’ indifference/ reluctance
Informants tend to hide their income and
exaggerate their expenditure
Investigators are posted at a place where
local people’s language is not known to the
Investigator
To manage with contract investigators due to
large no. of vacancies in regular posts
Data Processing Division (DPD)
Located at Kolkata and headed by Addl. Director
General
Major Functions
To undertake data-processing and tabulation
for
various NSS rounds and other adhoc surveys.
• To provide technical assistance to the SSBs/ DESs for
processing and tabulation of NSS State sample data
and also for pooling central and state sample data.
• To impart training on IT and data processing.
• To undertake special tabulation work for Ministries/
Govt. Departments.
Activities of Data Processing
-Finalisation of sampling frame in consultation with SDRD
-Software development for generation of sample list as per
the design and drawing sample as per allocation
-Software development for data entry, verification and
validation for central and state sample
-Training Manual preparation (system design, data layout,
PDES and CSP points)
-PDES inconsistencies taken up with FOD
-Phase-I validation, CSP (Content check)
-Phase-II validation (Coverage check)
-Phase-III validation (Howler check)
-Software for estimation procedure and computation of
multiplier
-Generation of trial and final tables
-Dissemination of unit level data
Coordination & Publication Division (CPD)
Located at New Delhi and headed by a Dy. Director
General
• Functions as technical secretariat for DG&CEO
• CPD is responsible for:
– Coordinating the activities of all the four divisions of
NSSO
– Dissemination of survey results
– Publication of the biannual technical journal
"Sarvekshana".
– Supplying survey data of various rounds to individuals,
research scholars, research Institutions and other
private and government bodies
– Liaison with other Departments/Ministries on various
matters concerning NSSO.
– Dealing with Parliament questions.
Different Activities during one Round of NSS
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Deciding subject and formation of Working Group (WG)
WG deliberations
– Subject coverage, concepts and definitions, sampling design, draft survey
instruments
Finalisation of survey instruments
– Training manual and survey instruments ,
– AITOT
– Sample selection and dissemination of Sample List (Central and State
sample)
– Tabulation plan and estimation procedure
– Quality control instruments
• FSP, PDES, CSP,
• Consolidated clarification on field queries post RTC
• Reply of queries from field offices of FOD & DES on regular basis.
Data validation
– Computer Edit Programme (CEP), Trial tables, Final tables
Report finalisation and Dissemination
– First draft, in-house discussion, 2nd draft, draft circulation, assimilation of
comments, approval by NSC
– printing, press release, release of report
– Dissemination, sale and documentation
Subjects Coverage in recent Past
NSS 71st round (Jan - June, 2014)
1.Social Consumption: Health and Education
NSS 70th round (Jan - Dec, 2013)
1. Land & Livestock holdings and Debt & Investment
2. Situation Assessment of Farmers
NSS 69th Round (July - Dec, 2012)
1. Housing conditions, Drinking Water Supply & Sanitation and Hygiene
NSS 68th round (July, 2011 - June, 2012)
1. Employment & Unemployment
2. Household Consumer expenditure
NSS 67th Round (July, 2010 - June, 2011)
1.Unincorporated non-agricultural enterprises in manufacturing, trade and
other services sector (excluding construction)
Subject coverage for current round
NSS 72nd round (Jul 2014 - Jun 2015)
Consumer Expenditure, Domestic Tourism and
Household Consumption of Durable Goods and
Services
Data Users
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Planning Commission - Employment & Unemployment
and Household Consumer Expenditure.
National Accounts Division, CSO - Employment &
Unemployment, Household Consumer Expenditure,
Unorganised Manufacturing, Unorganised Services,
Debt & Investment.
Reserve Bank of India - Debt & Investment.
Ministry of Labour - Employment & Unemployment.
Various other Ministries & Departments (Health,
Education, Women & Child Development etc.) - Socio
Economic Surveys, Land & Livestock Holdings etc.
Research Scholars (worldwide).
UN Agencies (IMF, UNICEF, FAO etc.)
Basic Concepts of Survey Sampling Theory
1
Statistical Survey Sampling
 Statistical Survey Sampling is a systematic
approach to selecting a few elements (a sample)
from an entire collection of data (a population) in
order to make some inferences about the total
population.
 The sampling methods help us to ensure that
samples represent the entire population.
 A sample of fairly modest size is sufficient to give
a reasonable idea of a much larger universe.
2
Advantages of Survey Sampling




less expensive
timeliness
wider range of survey data
wider choice of methods of observation,
measurement or questioning
 results subject to smaller non-sampling
errors
3
Disadvantages of Survey Sampling
 results of a sample survey are subject to
sampling errors.
 a sample may seriously over-represent,
under-represent, or even fail to represent
infrequently-occurring subgroups of a
population.
 results at disaggregated levels may not
be reliable.
4
Principal Steps in a Sample Survey
1. Objective of the Survey
2. Defining the Population to be Sampled
3. The Frame and Sampling Units
4. Selection of Proper Sampling Design
5. Data to be collected
6. The Questionnaire or Schedule
5
Principal Steps in a Sample survey (contd.)
7. Method of Collecting Information
(i) Interview Method
(ii) Mailed Questionnaire Method
8. Organisation of field Work
9. Treatment of non-response
10. The Pretest
11. Summary and Analysis of the Data
(i)
Scrutiny and editing of the data
(ii)
Tabulation of data
(iii)
Statistical analysis
(iv)
Reporting and conclusions
6
Sampling and Non-sampling Errors
7
The theory of survey sampling

includes a variety of sample selection
and estimation methods

its objective is to obtain a reasonably
representative sample
Methods of Sampling – three
broad categories

The three broad categories of methods
of sampling are
(a) Non-probability sampling
– Subjective or purposive or
judgment sampling
(b) Probability sampling
(c) Mixed Sampling
9
Sample Design specifies
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
ix.
the population to be surveyed, sample units to
adopt and different stages of selection if required
sample selection method,
sampling frame to use (list of units, maps of area),
size of the sample,
stratification,
allocation of size to different strata,
statistic to be used
treatment of non-response
estimation procedure of sampling error.
Sample Selection Procedures / Schemes
Some of the common selection methods of
sample are:
a. Simple Random Sampling
b. Systematic Sampling
c. Stratified Sampling
d. Cluster Sampling
e Probability Proportional-to-size Sampling
f. Multi-stage sampling.
11
Stratified Sampling
 In this sampling procedure, we divide the
population into relatively homogeneous groups
called Strata.
 Then from each stratum randomly select a
specified number of elements using any of the
following two criteria:
 Proportional allocation
 Optimum allocation
 Greater the difference in the stratum means,
greater is the gain in precision of stratified
sampling over un-stratified simple random
sampling.
12
Allocation of Sample size
In proportional Allocation
ni = (n/N)*Ni
Or n1/N1 = n2/N2 ………= nk/Nk = n/N
In optimum allocation ni’s are chosen so
as to
(a) Maximise the precision for (i) fixed sample
size n or (ii) fixed cost
(b) Minimise the total cost for fixed precision
13
Advantages of Stratified Random Sampling
(i) More representative
(ii) Greater accuracy
(iii) Administrative convenience
(iv) Very useful in the fields of highly skewed
distributions
14
Multistage Sampling
As the name suggests, multistage sampling refers to a
sampling technique, which is carried out in various stages.
Example:
If we are interested in obtaining a sample of households from
rural areas of a particular State, the first stage units may be
districts, the second staged units may be villages in the districts
and third stage units will be households in the villages.
 Each stage thus results in a reduction of the sample size.
Contd….
• Multistage sampling consists of sampling first stage units by
some suitable method of sampling.
• From among the selected first stage units, a sub-sample of
secondary stage units is drawn by some suitable method of
sampling which may be same as or different from the method
used in selecting first stage units.
• Further stages may be added to arrive at a sample of the
desired sampling units.
Merits and Limitations of Multistage sampling
• Multistage sampling is more flexible as compared to other
methods of sampling.
• It is simple to carry out and results in administrative
convenience by permitting the field work to be concentrated,
yet covering large area.
• Most practical advantage of multistage sampling is that we
need the second stage frame only for those units which are
selected in the first stage sample.
• This leads to great saving in operational cost.
• However, a multistage sampling is generally less efficient
than a suitable single-stage sampling of the same size.
Sampling Design used in Socio-economic Surveys
undertaken by NSSO
A stratified multi-stage sampling design is generally used
in Socio-economic Surveys undertaken by NSSO.
The first stage units (FSU) are the 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) are households in both
Rural & Urban Sectors.
In case of large FSUs, one intermediate stage of sampling
is done by selecting two hamlet groups/ sub blocks from
each of such rural/ urban FSU respectively.
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NSS 72nd ROUND
(July 2014 – June 2015)
‘Consumer Expenditure’
‘Domestic Tourism Expenditure’
‘Household Expenditure on
Services and Durable Goods’
Sample Design
1
Schedules of enquiry
Schedule 0.0
List of Households
Schedule 1.60
Household Consumer Expenditure (4)
Schedule 1.61
Household Consumer Expenditure
with details of Food Consumption (4)
Schedule 1.62
Household Consumer Expenditure
with details of Non-Food
Consumption (4)
Domestic Tourism Expenditure (10)
Schedule 21.1
Schedule 1.5
Sample Design
Household Expenditure on Services
and Durable Goods (6)
2
Coverage and sample design
Sample Design
3
Geographical coverage
Whole of the Indian Union except the
villages in Andaman and Nicobar
Islands which remain extremely
difficult to access due to the restriction
imposed by local authorities
Sample Design
4
Participation of States/ UTs
State/UT
Nagaland (U)
Sample Design
Extent of
matching
triple
Andhra Pradesh, J & K ,
Manipur, Odisha, Delhi
double
Maharashtra (U)
one and half
Remaining States/ UTs
equal
5
Work Programme and Sub-rounds

The survey will be of one year duration starting from
1st July 2014 and ending on 30th June 2015.

Survey period will be divided into four sub-rounds
of three months’ duration each, as follows:
sub-round 1 : July - September 2014
sub-round 2 : October - December 2014
sub-round 3 : January - March 2015
sub-round 4 : April - June 2015
Sample Design
6
Work Programme and Sub-rounds
Sample Design

In each of these four sub-rounds equal number
of sample villages/ blocks (FSUs) will be allotted
for survey.

Because of the arduous field conditions, this
restriction is not strictly enforced in Andaman
and Nicobar Islands, Lakshadweep, Leh
(Ladakh) and Kargil districts of Jammu &
Kashmir and rural areas of Arunachal Pradesh
and Nagaland.
7
Sample Design - Outline
A stratified multi-stage design will be
adopted for the 72nd round survey.
 First Stage Units (FSU) –

 2011 Census list of villages in the rural sector
 Urban Frame Survey (UFS) blocks (UFS
2007-12 Phase) in the urban sector
In case of large FSUs, hamlet-groups (hg’s) in
rural areas and sub-blocks (sb’s) in urban
areas will form the intermediate stage units.
 The ultimate stage units (USU) will be
households in both the sectors.

Sample Design
8
Total sample size (FSUs)

14088 FSUs are allocated for central sample
at all-India level.
◦ 8016 for Rural Sector
◦ 6072 for Urban Sector
Sample Design
9
Allocation – central sample
Sample Design

Allocation of total sample to States/UTs:
Proportional to State/UT population as per
Census 2011.

A minimum of 16 FSUs (minimum 8 each for
rural and urban sectors separately) will be
allocated to each State/ UT.

State/ UT level sample size is to be allocated
between two sectors in proportion to
population as per Census 2011 with double
weightage to urban sector.
10
Stratification
Within each district of a State/UT, two basic
strata will be formed:
◦ (i) rural stratum comprising all rural areas of
the district and
◦ (ii)
urban stratum comprising all the urban
areas of the district.
Sample Design
11
Sub-stratification - Rural
Sample Design

If ‘r’ be the sample size allocated for a rural
stratum, the number of sub-strata formed will
be ‘r/4’.

The villages within a district as per frame will
be first arranged in ascending order of
population.

Then sub-strata 1 to ‘r/4’ will be demarcated in
such a way that each sub-stratum will comprise
a group of villages of the arranged frame and
have more or less equal population.
12
Sub-stratification - Urban
Sample Design

Let, ‘u’ be the sample size allocated for an urban
stratum

‘u/4’ sub-strata will be formed within each stratum

UFS blocks identified as ‘Affluent Area’ within the
stratum is made separate sub-strata
13
Sub-stratification – Urban (contd.)
Sample Design

if there is no ‘Affluent Area’ block in the stratum, all
the UFS blocks will be divided into ‘u/4’ sub-strata

if only one sub-stratum is formed with the ‘Affluent
Area’ blocks, then all the remaining non-affluent
blocks will be divided into ‘(u-4)/4’ sub-strata

if two sub-strata are formed with the ‘Affluent Area’
blocks, then all the remaining non-affluent blocks
will be divided into ‘(u-8)/4’ sub-strata
14
Sub-stratification – Urban (contd.)
Sample Design

All the UFS blocks within the stratum will be first
arranged in ascending order of total number of
households in the UFS Blocks as per UFS phase
2007-12

Sub-strata will be demarcated in such a way that each
sub-stratum will have more or less equal number of
households

The above procedure will be followed separately for
‘affluent’ and ‘non-affluent’ part of the stratum
15
Allocation to strata and sub-strata
 Allocations
at stratum level will be adjusted to
multiples of 4 with a minimum sample size of 4.
 For
both rural and urban stratum, allocation
will be 4 for each sub-stratum.
Sample Design
16
Selection of FSUs
 Rural
sector - Probability Proportional to Size
With Replacement (PPSWR), size being the
population of the villages as per Census 2011.
 Urban
sector - Probability Proportional to Size
With Replacement (PPSWR), size being the number
of households of the UFS blocks as per UFS phase
2007-12.
 Equal
number of samples will be allocated among
the four sub rounds.
Sample Design
17
Usual criterion for hamlet-group/
sub-block formation
Selected FSUs with approximate population
1200 or more will be divided into a suitable
number of ‘hamlet-groups’ in the rural sector
and ‘sub-blocks’ in the urban sector with more
or less equal population.
Sample Design
18
Usual criterion for hamletgroup/ sub-block formation
approximate present population no. of hg’s/sb’s
to be formed
of the sample FSU
Sample Design
less than 1200
1
1200 - 1799
3
1800 - 2399
4
2400 - 2999
5
3000 - 3599
6
…..and so on
-
19
For rural areas of Himachal Pradesh, Sikkim, Andaman &
Nicobar Islands, Uttarakhand (except four districts
Dehradun, Nainital, Hardwar and Udham Singh Nagar),
Poonch, Rajouri, Udhampur, Reasi, Doda, Kistwar,
Ramban, Leh (Ladakh), Kargil districts of Jammu and
Kashmir and Idukki district of Kerala
approximate present population
of the sample FSU
less than 600
600 - 899
900 - 1199
1200 - 1499
1500 - 1799
…..and so on
Sample Design
no. of hg’s to be
formed
1
3
4
5
6
20
Selection of hamlet-groups/ sub-blocks
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

Sample Design
Formation of hg/sb: By equalizing population
maintaining geographical contiguity.
Two hg’s/ sb’s will be selected:
• The hg/sb with the largest percentage share of
population will always be selected and termed
hg/sb 1;
• one more hg/sb will be selected from the
remaining hg’s/sb’s by Simple Random Sampling
(SRS) and termed hg/sb 2.
Listing and selection of the households will be done
independently in the two selected hamlet-groups/
sub-blocks.
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Selection of households
From each selected FSU and hg/sb, the
sample households for each of the schedules
will be selected by SRSWOR.
Sample Design
22
Sample Design
23