UPSC Indian Statistical Service (ISS) Provisional Answer Key 2026 - Statistics Paper I & II Released Download PDF

The Union Public Service Commission (UPSC) conducts the Indian Statistical Service (ISS) examination annually to recruit candidates for statistical positions in various Ministries and Departments of the Government of India. This is an All India examination for graduates with Mathematics/Statistics background. The ISS exam selects candidates for the Indian Statistical Service and Indian Statistical Service (Junior Time Scale), which are Group A gazetted posts under the Central Government. Selected candidates work in statistical analysis, data interpretation, survey design, and policy research across departments like Ministry of Statistics & Programme Implementation, Planning Commission, and other statistical wings. The provisional answer key for Statistics Paper I & II allows candidates to verify their responses and raise objections if needed before the final result declaration.

Important Dates (Typical / Indicative)

Vacancy Details (Typical / Indicative)

Note: Actual vacancies vary year-to-year based on government requirements. PwD reservations apply horizontally.

Educational Qualification

Essential Qualification:

• Bachelor's degree from a recognized University with at least one of the following subjects:
• Statistics
• Mathematical Statistics
• Applied Statistics
• Mathematics
• Candidates appearing in final year/semester can also apply (subject to completing degree before document verification)

Preferred: Post-graduation in Statistics/Mathematical Statistics adds advantage during interview

Age Limit

Age as on 1st August 2026:

Age Relaxation:

Nationality

A candidate must be either:

• A citizen of India, OR
• A subject of Nepal, OR
• A subject of Bhutan, OR
• A Tibetan refugee who came to India before 1st January 1962 with intention of permanent settlement, OR
• A person of Indian origin migrated from Pakistan, Burma, Sri Lanka, East African countries of Kenya, Uganda, Tanzania, Zambia, Malawi, Zaire, Ethiopia, or Vietnam with intention to permanently settle in India

Note: Candidates in categories (2) to (5) must obtain Certificate of Eligibility from Government of India

How to Apply Online

1. Visit Official Website: Go to https://upsconline.nic.in or www.upsc.gov.in
2. One-Time Registration (OTR): If new user, complete OTR-I registration by providing basic details, email and mobile number. Verify email/mobile through OTP
3. Complete OTR-II: Fill educational qualifications, upload photo (3.5cm × 3.5cm, 10-40 KB JPEG), signature (4cm × 2cm, 3-12 KB JPEG), and ID proof
4. Login to Part-I: Use registration ID and password to login for ISS exam application
5. Fill Application Form: Complete all mandatory fields including personal details, educational qualifications, category, exam centre preferences
6. Upload Documents: Upload scanned copies of photograph, signature, and required certificates (format: JPEG, size limits specified)
7. Fee Payment: Pay application fee through online mode (Net Banking/Credit Card/Debit Card/UPI) or generate SBI Challan for offline payment
8. Submit Application: Review all details carefully and submit the application form
9. Take Printout: Download and save the confirmation page and fee receipt for future reference

Application Fee Structure

Payment Mode: Online (Net Banking/Cards/UPI) or Offline (SBI Branch Challan)

Note: Fee once paid shall not be refunded under any circumstances

Selection Stages

The selection for Indian Statistical Service comprises the following stages:

1. Written Examination (Mains): Candidates appear for a comprehensive written examination consisting of multiple papers covering Statistics, Mathematics and General Studies. This is the primary screening stage worth 1000 marks total. There is no preliminary examination for ISS.

1. Personality Test/Interview: Candidates who qualify the written examination based on cutoff marks are called for personality test conducted by UPSC board. The interview carries 200 marks and assesses candidate's intellectual calibre, knowledge depth, communication skills, and suitability for statistical services.

1. Document Verification: Candidates provisionally selected after interview must appear for document verification where all original certificates (educational qualifications, age proof, caste certificate, EWS certificate, PwD certificate etc.) are verified by the concerned authority.

1. Medical Examination: Selected candidates undergo medical examination to ensure physical and mental fitness as per government standards. Candidates must meet minimum physical standards prescribed for government service.

1. Final Merit List: Final selection is based on combined marks of Written Examination (1000 marks) + Interview (200 marks). Merit list is prepared category-wise and candidates are allocated to ISS or ISS (JTS) based on rank and preferences.

1. Training: Selected candidates undergo Foundation Course at LBSNAA Mussoorie followed by professional training at Indian Statistical Institute or other designated institutions before joining their assigned departments.

UPSC ISS Examination Pattern

Note: ISS does not have a Preliminary examination. Only Mains examination is conducted.

Mains Examination Pattern

Marking Scheme Details

Negative Marking: There is NO negative marking in ISS examination as all papers are descriptive/subjective in nature.

Qualifying Marks:

• Candidates must secure minimum qualifying marks in each paper (typically 25% i.e., 50 marks out of 200)
• Overall aggregate percentage required varies based on competition and category
• Interview has no minimum qualifying marks

Medium of Examination: All papers except General English can be attempted in Hindi or English as per candidate's choice.

ISS Examination Detailed Syllabus

Paper I: General Economics and Indian Economics

Section A: General Economics

• Theory of Demand and Supply
• Theory of Production and Cost
• Market Structure (Perfect Competition, Monopoly, Oligopoly)
• Factor Pricing and Income Distribution
• National Income Accounting
• Money and Banking
• Public Finance and Fiscal Policy
• International Trade and Balance of Payments
• Economic Growth and Development Theories
• Welfare Economics

Section B: Indian Economics

• Indian Economy: Pre and Post Independence
• Planning and Economic Development in India
• Agriculture: Issues and Reforms
• Industrial Development and Policy
• Foreign Trade and BOP in Indian Context
• Monetary and Fiscal Policy in India
• Banking and Financial Institutions
• Poverty, Unemployment and Inequality
• Infrastructure Development
• Recent Economic Reforms and GST

Paper II: General English

• Essay Writing on contemporary topics
• Comprehension and Précis Writing
• Grammar and Usage
• Vocabulary and Idioms
• Letter Writing (Official and Personal)
• Report Writing
• Translation from Hindi to English
• Note Making

Paper III: Statistics-I

Probability:

• Sample Space and Events
• Axiomatic Definition of Probability
• Conditional Probability and Independence
• Bayes' Theorem and Applications
• Random Variables (Discrete and Continuous)
• Distribution Functions
• Expectation and Moments
• Probability Generating Functions and Moment Generating Functions
• Standard Discrete Distributions (Binomial, Poisson, Geometric, Negative Binomial)
• Standard Continuous Distributions (Normal, Exponential, Gamma, Beta, Uniform)
• Bivariate Distributions
• Marginal and Conditional Distributions
• Independence of Random Variables
• Transformations of Random Variables
• Chebychev's Inequality
• Weak Law of Large Numbers
• Central Limit Theorem

Statistical Inference:

• Sampling Distributions
• Chi-square, t and F distributions
• Point Estimation: Methods and Properties
• Sufficiency, Consistency, Unbiasedness, Efficiency
• Cramer-Rao Inequality
• Maximum Likelihood Estimation
• Method of Moments
• Interval Estimation: Confidence Intervals
• Testing of Hypotheses: Concepts and Types of Errors
• Neyman-Pearson Lemma
• Likelihood Ratio Tests
• Tests for Parameters of Normal Distribution
• Chi-square Test for Goodness of Fit and Independence

Paper IV: Statistics-II

Linear Models:

• Simple Linear Regression
• Multiple Linear Regression
• Least Squares Estimation
• Gauss-Markov Theorem
• Tests for Regression Coefficients
• Analysis of Variance (One-way and Two-way Classification)
• Multiple Comparison Tests
• Assumptions and Diagnostics

Design of Experiments:

• Principles of Experimental Design
• Completely Randomized Design (CRD)
• Randomized Block Design (RBD)
• Latin Square Design (LSD)
• Factorial Experiments (2^n and 3^n)
• Confounding in Factorial Experiments
• Split Plot Design
• Missing Plot Technique

Sampling Theory:

• Need for Sampling
• Simple Random Sampling (with and without replacement)
• Stratified Random Sampling
• Systematic Sampling
• Cluster Sampling
• Ratio and Regression Methods of Estimation
• Double Sampling
• Non-Sampling Errors

Paper V: Statistics-III

Numerical Analysis:

• Solution of Algebraic and Transcendental Equations
• Interpolation (Newton, Lagrange)
• Numerical Differentiation and Integration
• Solution of Ordinary Differential Equations

Optimization Techniques:

• Linear Programming Problem formulation
• Graphical and Simplex Methods
• Duality Theory
• Transportation and Assignment Problems

Demographic Methods:

• Measures of Mortality and Fertility
• Abridged Life Tables
• Population Growth Models
• Stable Population Theory

Statistical Quality Control:

• Chance and Assignable Causes
• Control Charts for Variables (X-bar, R, s charts)
• Control Charts for Attributes (p, np, c, u charts)
• Acceptance Sampling Plans
• OC, AOQ, ATI Curves

Time Series Analysis:

• Components of Time Series
• Trend Analysis
• Seasonal Variations
• Forecasting Methods
• Moving Averages
• Exponential Smoothing

Official Statistics:

• National Income Estimation
• Index Numbers: Construction and Uses
• Consumer Price Index and Wholesale Price Index
• Agricultural and Industrial Statistics
• Vital Statistics
• Role of NSSO and CSO

ISS Salary Structure (Typical / Indicative as per 7th Pay Commission)

Additional Benefits:

• Central Government Health Scheme (CGHS) medical facilities
• Leave Travel Concession (LTC)
• Children Education Allowance (₹2,250 per child for max 2 children)
• Pension benefits under New Pension Scheme (NPS)
• Government accommodation or HRA
• Annual increments (3% of basic pay)
• Professional Update Allowance for statistical work
• Telephone/Internet reimbursement

Promotion Scale: After promotions, salary can reach ₹2,25,000+ per month (Level 13-14) in senior positions.

Note: Actual in-hand salary varies based on city of posting, deductions, and individual allowances claimed.

ISS officers enjoy excellent career progression with well-defined promotion avenues. Starting as Junior Time Scale (JTS) officer at Level 10, officers get promoted to Senior Time Scale (Level 11) after 4 years, Selection Grade (Level 12) after 9 years, Senior Administrative Grade (Level 13) after 13 years, and can reach Higher Administrative Grade (Level 14) and apex scale positions (Level 15-16) as Chief Statistical Officer or Director in various Ministries. Officers also get opportunities for deputation to international organizations like UN, World Bank, and can pursue higher research/academic roles alongside administrative responsibilities.

UPSC releases admit cards for ISS Mains examination approximately 3 weeks before the exam date. Candidates can download their e-admit cards from the official UPSC website (upsconline.nic.in) using their registration ID and password or roll number and date of birth. The admit card contains crucial details like exam centre address, reporting time, candidate's photograph and signature, and important instructions. No postal dispatch of admit cards is done; candidates must download and carry a printout along with original valid photo ID proof to the examination centre.

UPSC declares ISS results in multiple stages. The Mains written examination result is published 6-8 weeks after the exam, listing roll numbers of candidates qualified for personality test. After interviews, the final result with merit list and category-wise cutoff marks is declared, typically 2-3 months after completion of interviews. Results are available on UPSC official website and candidates receive individual scorecards. The final merit list includes marks obtained in written exam, interview, and total score determining allocation to ISS or ISS (JTS) based on rank and vacancies.

ISS cutoff marks vary significantly year-to-year based on paper difficulty and candidate performance. Typically, General category candidates need around 450-500 marks out of 1000 in written exam to qualify for interview (45-50%), while OBC candidates require 420-470 marks (42-47%), SC candidates 380-430 marks (38-43%), and ST candidates 350-400 marks (35-40%). Final selection cutoffs including interview are usually 50-55% for General, 45-50% for OBC, 40-45% for SC, and 35-40% for ST category. Candidates scoring above these percentages generally secure selection depending on total vacancies.

ISS Examination Centres

UPSC conducts ISS examination at the following centres across India:

North: Delhi, Chandigarh, Jaipur, Lucknow, Dehradun, Shimla, Jammu, Srinagar

South: Bengaluru, Chennai, Hyderabad, Thiruvananthapuram, Kochi, Visakhapatnam, Tirupati, Mysuru

East: Kolkata, Patna, Ranchi, Bhubaneswar, Cuttack, Siliguri

West: Mumbai, Ahmedabad, Pune, Nagpur, Surat, Indore, Vadodara

Northeast: Guwahati, Dispur, Shillong, Imphal, Agartala, Kohima, Aizawl, Itanagar

Central: Bhopal, Raipur, Jabalpur, Allahabad

Candidates can choose 3 exam centre preferences during application. UPSC allots centre based on availability and administrative feasibility. Centre once allotted cannot be changed under any circumstances.