What a Price Index Is: Base Year, Basket and WeightsImportance 3/5UPSC 1998
How does an index number work? Understand the base year and its fixed starting value, using a simple example of two years of price rise. Why does an index need a basket and weights, and why do weights stay fixed until the base is revised? How is the inflation rate read from an index?
Base EffectImportance 4/5UPSC 2011
Does a low base raise or lower the measured inflation rate, and what about a high base? Understand how the previous year's price level changes the year-on-year rate, using an onion price example. How do seasonal swings in food and fuel create favourable and unfavourable base effects in news reports?
Consumer Price Index and Its Series in IndiaImportance 5/5UPSC 2015, 2020
What does the Consumer Price Index measure? Know the CPI series used in India (industrial workers, agricultural labourers, rural labourers, and rural, urban and combined), which body compiles each, and what each is used for. Why do group-specific series exist? Does CPI include indirect taxes and services? Know the current base year of each series.
New CPI Series (Base 2024): Basket and WeightsImportance 4/5
Why was the CPI revised to a 2024 base? Understand the new structure of divisions, the wider basket, rural housing and the use of online prices. Know the survey the weights come from. Did the weight of food rise or fall, and what does that change for the volatility of headline inflation?
Consumer Food Price IndexImportance 2/5
Which prices does the Consumer Food Price Index track, and how does it relate to the CPI? Why is it the usual measure of food inflation in official releases?
Headline Inflation and Core InflationImportance 4/5
Which items does core inflation leave out, and why do policymakers watch it next to headline inflation? Understand why food, fuel and core inflation are read separately. Why can gold and silver prices distort core inflation? Know the core measure that the RBI reports with precious metals excluded.
Wholesale Price Index: Compiler, Coverage and Major GroupsImportance 5/5UPSC 4 Years
Who compiles the Wholesale Price Index, and how often? At what stage of trade are its prices taken, and how do they differ from retail prices? Why are services outside it? Remember its three major groups and which one is the largest. What is it used for?
New WPI Series (Base 2022-23)Importance 4/5
Know who recommended the revision of the WPI to a 2022-23 base. Understand the main changes: the larger basket, the new basis for weights, the shift of crude petroleum and natural gas between groups, the new kinds of electricity added, and the dropping of the minimum support price as a price source.
Producer Price Index and the Move from WPIImportance 4/5
Compare the Producer Price Index with the WPI on services, classification and export-oriented units. How do the Output PPI and the Input PPI differ in the price taken? Which producer price indices does India now compile? Why does a PPI suit double deflation? What is the plan to move from WPI to PPI, and does WPI continue alongside for a time?
GDP Deflator: Meaning and CalculationImportance 4/5
Be able to explain how the GDP deflator is derived from nominal and real GDP, using a simple one-good example over two years. Why is it called an implicit deflator, and which body publishes it? How do WPI, CPI and now PPI help move GDP between current and constant prices? What is double deflation?
CPI, WPI and GDP Deflator ComparedImportance 5/5UPSC 1997, 2010, 2020
How do the three differ on services, intermediate and capital goods, and weights? Do imported goods still enter the WPI basket after its switch to output-based weights? Why can WPI inflation and CPI inflation move apart? Why is the GDP deflator the broadest of the three?