OFFICIAL STATISTICS SPECIALLY DESIGNED FOR INDIAN STATISTICAL SERVICE (ISS) AND OTHER GOVERNMENT & PRIVATE SECTOR STATISTICAL EXAMINATIONS
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When a headline says "India's unemployment rate was 3.2% in 2023-24," the number comes from the Periodic Labour Force Survey (PLFS). It is the main source of employment and unemployment data in India, and a regular in the Indian Statistical Service (ISS) papers. It also appears in RBI, NABARD, SSC and university statistics exams. This guide gives you the concepts, the formulas and three exam-style questions.
1. What is the Periodic Labour Force Survey?
PLFS is a household sample survey that measures the size and structure of the workforce: how many people are working, how many are looking for work, and how many are outside the labour force. It started in April 2017 and replaced the quinquennial Employment-Unemployment Surveys of the NSS, because policymakers needed data much more often than once in five years.
Why examiners love this topic
PLFS brings together survey design, reference periods, ratio estimation and definitions in one place. A question can ask for a definition, a calculation of LFPR, WPR and UR, or a comparison of usual status with weekly status.
2. Who conducts PLFS and how?
The National Statistics Office (NSO) under the Ministry of Statistics and Programme Implementation (MoSPI) runs the survey. Since 2025 the survey has been revamped to give more frequent all-India estimates, with monthly and quarterly bulletins and annual reporting on a calendar-year basis. Always check the latest MoSPI release for the current format.
Design
Stratified multi-stage sampling. In urban areas the original design used a rotational panel: each household was visited four times.
Reference period
Usual status looks back over 365 days. Current weekly status looks back over the last 7 days.
Indicators
Labour Force Participation Rate (LFPR), Worker Population Ratio (WPR) and Unemployment Rate (UR).
Exam tip
Headline PLFS figures usually refer to persons aged 15 years and above. Youth figures (15 to 29 years) are reported separately. Always check which age group and which status the question is using.
3. The formulas: LFPR, WPR and UR
A person is in the labour force if employed or unemployed (seeking or available for work). Everyone else, such as students and those engaged in domestic duties, is outside it.
Here E is the number of employed, U the number of unemployed and P the population of the age group considered. Note that the unemployment rate uses the labour force as the denominator, not the total population.
- Strength: frequent, nationally comparable data with clear definitions.
- Weakness: it is a sample survey, so estimates have sampling error, especially for small domains.
- Relation to remember: UR = (1 − WPR / LFPR) × 100.
4. LFPR trend at a glance (Usual status, age 15+, all India)
Notice how LFPR has risen steadily since 2017-18. Much of this rise came from higher participation of women, especially in rural areas.
Values are LFPR in per cent (usual status, PS+SS, age 15 years and above) from annual PLFS reports. Verify against the latest MoSPI release before quoting.
5. Usual status vs current weekly status: the comparison that keeps coming up
| Basis | Usual status (PS+SS) | Current weekly status (CWS) |
|---|---|---|
| Reference period | Preceding 365 days | Preceding 7 days |
| Principal status | Activity on which the person spent the longer time during the year | Not applicable |
| Subsidiary status | Another activity for at least 30 days | Not applicable |
| Employed if | Principal or subsidiary activity is work | Worked at least one hour on any day in the week |
| Best for | Structural, long-run picture | Short-run changes, quarterly and monthly tracking |
6. Common mistakes students make
- Dividing unemployed persons by total population. UR uses the labour force in the denominator.
- Treating LFPR and WPR as the same. LFPR includes the unemployed, WPR does not.
- Saying PLFS is conducted by the Labour Bureau or the Ministry of Labour. It is NSO, MoSPI.
- Comparing a usual status figure with a weekly status figure as if they were the same measure.
- Counting students and homemakers as unemployed. They are outside the labour force.
7. Three important questions on PLFS
Try each one on your own first, then tap the answer.
Define LFPR, WPR and the unemployment rate, and state the relation between them.
Show answer
LFPR is the number of persons in the labour force (employed plus unemployed) per 100 persons of the population. WPR is the number of employed persons per 100 persons of the population. UR is the number of unemployed persons per 100 persons in the labour force. They are related by UR = (1 − WPR / LFPR) × 100.
In a sample of 20,000 persons aged 15 years and above, 11,600 are employed and 400 are unemployed. Compute LFPR, WPR and the unemployment rate, and verify the relation between them.
Show answer
Labour force = 11,600 + 400 = 12,000
LFPR = 12,000 / 20,000 × 100 = 60.0%
WPR = 11,600 / 20,000 × 100 = 58.0%
UR = 400 / 12,000 × 100 = 3.33%
Check: (1 − 58 / 60) × 100 = 3.33%, so the relation holds.
Distinguish between usual status and current weekly status approaches in labour force surveys. Why does PLFS use both?
Show answer
Write your answer in four parts. (a) Usual status: the reference period is 365 days. A person is classified by the activity on which the longer time was spent (principal status), and a subsidiary activity of at least 30 days can also be recorded. The two together give the PS+SS estimate. (b) Current weekly status: the reference period is the last 7 days. A person is employed if he or she worked at least one hour on any day of that week. (c) Why both: usual status gives a stable, structural picture of the workforce, while weekly status captures short-run changes and is suited to quarterly and monthly reporting. (d) Comparability: the two measures differ in concept, so their levels are not directly comparable. Conclude that using both makes PLFS useful for long-run policy as well as for timely monitoring.
Key takeaways
- PLFS is conducted by NSO, MoSPI and is the main source of employment and unemployment data.
- LFPR = (E + U) / P, WPR = E / P and UR = U / (E + U), each multiplied by 100.
- Usual status uses a 365-day reference period; current weekly status uses 7 days.
- Know the UR, LFPR and WPR relation cold. It is a likely exam question this year.
Everything on Official Statistics, in one book
This topic is just one chapter of the syllabus. If you want the complete picture, this book is built for you.
- Indian official statistical system: MoSPI, NSO, NSC and the data they produce
- National accounts, GDP, IIP, price indices and labour statistics
- NSS surveys, sampling designs and data quality concepts
- Written specially for the ISS exam, and useful for other government and private sector statistical exams
- Concept-focused notes to revise quickly before the exam
Official Statistics for ISS and other Government & Private Sector Statistical Examinations