Deflators, discrepancies, data sources: After 11 years, India’s GDP set to get updated
The statistics ministry will release GDP data with 2022-23 as the base year at 4pm on Friday.
After more than a decade of questions and debates, India is set to finally get an updated gauge of its GDP, with the Ministry of Statistics and Programme Implementation (MoSPI) set to unveil the new data series at 4pm on Friday.
“Over the past two years, the Advisory Committee on National Accounts Statistics (ACNAS) and its five sub-committees had more than 40 formal meetings,” a senior official from the statistics ministry said, requesting anonymity.
The revision of India’s GDP data is important for several reasons. Chief among them is that it will present the most accurate picture of the structure of the Indian economy. Since January 2015 – when the current GDP series was released with 2011-12 as the base year for prices to calculate real growth – India’s economy has undergone huge changes; for instance, digital sectors such as e-commerce have become more prominent.
Procedurally, too, GDP data should be regularly updated. This, along with the continued use of 2011-12 as the base year, led to the International Monetary Fund in December 2025 retaining its ‘C’ grade for India’s GDP data.
MoSPI will release GDP data for October-December 2025 as per the new series with 2022-23 as the base year, along with the Second Advance Estimate for 2025-26. The First Advance Estimate, released in January as per the old series, pegged full-year growth at 7.4%. GDP data for the first two quarters of 2025-26 will also be revised.
Finally, annual and quarterly GDP data as per the new series will also be released for 2022-23, 2023-24, and 2024-25. This will help policymakers and economists understand how India’s recent growth trajectory has evolved as per the new series. However, it will take almost a year to get a ‘back series’ that shows GDP data for years before 2022-23 as per the new GDP series, with the MoSPI official quoted above saying the back series is expected to be released by December 2026.
“As per the practice, in India, back-series estimates are recalculated using revised methodology of the new GDP series up to the previous base year. After that, the data is linked at a disaggregated level and extended back to 1950-51. However, the final method for preparing the back-series will be decided in consultation with the Advisory Committee set up to guide MoSPI,” the official said.
The last time the GDP series was revised was in early 2015, with growth being raised for some years and lowered for others as MoSPI incorporated several methodological changes to measure the size of the Indian economy more accurately and comprehensively. But the magnitude of some revisions left economists puzzled, with even Raghuram Rajan, then the Governor of the Reserve Bank of India, saying the central bank found it “hard to see the economy as rollicking” in 2013-14 after growth for that year was raised to 6.9% (later revised to 6.4%) from 4.7% as per the 2004-05 GDP series.
The latest GDP series will also see major changes, the most crucial of which will be how nominal GDP is adjusted for price changes to arrive at real GDP. According to economists, India’s real GDP growth of 7.8% in April-June 2025 and 8.2% in July-September 2025 was likely overstated due to MoSPI’s use of the so-called single-deflator method.
To find a sector’s Gross Value Added (GVA), the value of inputs it uses is subtracted from the value of output it produces. This is GVA in current prices, or nominal terms. To find real GVA, the output and input values must be adjusted by their respective inflation rates – inputs by the rate at which their prices have changed and outputs by the change in prices consumers face. This is called double deflation.
However, MoSPI currently does this only for agriculture and mining and quarrying sectors. For others, it uses the same rate of inflation for both input and output prices, or the single-deflator method. This method is problematic when input and output prices change at different rates. When input prices are falling or rising at a slower pace than output prices, use of the single-deflator method can lead to overestimation of GVA, GDP, and growth – as was the case in 2025. And when input prices are rising at a faster pace than output prices, it can lead to underestimation of GVA and GDP.
The new GDP series will, in a major move, not use the single-deflator method at all. Deflators will also be used at a more granular level, allowing for more accurate measurement of real GDP growth.
Some other changes in the new series include the use of new sources of data and surveys (GST, e-Vahan, Annual Survey of Unincorporated Sector Enterprise, Periodic Labour Force Survey, among others). Further, by integrating national accounts data with Supply and Use Tables – which show how different goods and services are supplied by domestic industries and imports and how they are distributed between different intermediate or final uses, including exports – MoSPI is hoping to minimise the ‘discrepancy’ component which arises when GDP measured by the more reliable production approach does not match with the GDP calculated via the expenditure method. Large discrepancies can lead to significant revisions in GDP growth rates in the future while making it difficult to understand what is driving growth.
A key requirement for a new GDP series is a ‘normal’ year that will be used as the base year. However, the last decade has been repeatedly interrupted by disturbances: demonetisation in 2016, GST rollout in 2017, the coronavirus pandemic in 2020, and a sharp economic recovery in 2021. As such, 2022-23 presented the first opportunity to MoSPI.
But when will the next revision take place? According to statistics ministry officials, not before 2030. “Under normal conditions”, the ministry’s endeavour is to update GDP every five years, as done globally. However, the years immediately after 2029-30 are an opportune moment for the next GDP revision for another reason.
The 2008 System of National Accounts (SNA 2008) – the international statistical standard for national accounts data – is currently being used by India and other countries to compile GDP. Last year, the United Nations Statistical Commission adopted an updated version of these norms, called SNA 2025.
“The overall aim is to have a coordinated implementation process with the desired outcome of all countries implementing the standards within an implementation window of 2029-2030 as a target,” the United Nations Statistics Division said in its implementation strategy document.
“India plans to shift to SNA 2025 in its next base year revision,” the aforementioned MoSPI official said.
After more than a decade of questions and debates, India is set to finally get an updated gauge of its GDP, with the Ministry of Statistics and Programme Implementation (MoSPI) set to unveil the new data series at 4pm on Friday.
“Over the past two years, the Advisory Committee on National Accounts Statistics (ACNAS) and its five sub-committees had more than 40 formal meetings,” a senior official from the statistics ministry said, requesting anonymity.
The revision of India’s GDP data is important for several reasons. Chief among them is that it will present the most accurate picture of the structure of the Indian economy. Since January 2015 – when the current GDP series was released with 2011-12 as the base year for prices to calculate real growth – India’s economy has undergone huge changes; for instance, digital sectors such as e-commerce have become more prominent.
Procedurally, too, GDP data should be regularly updated. This, along with the continued use of 2011-12 as the base year, led to the International Monetary Fund in December 2025 retaining its ‘C’ grade for India’s GDP data.
MoSPI will release GDP data for October-December 2025 as per the new series with 2022-23 as the base year, along with the Second Advance Estimate for 2025-26. The First Advance Estimate, released in January as per the old series, pegged full-year growth at 7.4%. GDP data for the first two quarters of 2025-26 will also be revised.
Finally, annual and quarterly GDP data as per the new series will also be released for 2022-23, 2023-24, and 2024-25. This will help policymakers and economists understand how India’s recent growth trajectory has evolved as per the new series. However, it will take almost a year to get a ‘back series’ that shows GDP data for years before 2022-23 as per the new GDP series, with the MoSPI official quoted above saying the back series is expected to be released by December 2026.
“As per the practice, in India, back-series estimates are recalculated using revised methodology of the new GDP series up to the previous base year. After that, the data is linked at a disaggregated level and extended back to 1950-51. However, the final method for preparing the back-series will be decided in consultation with the Advisory Committee set up to guide MoSPI,” the official said.
The last time the GDP series was revised was in early 2015, with growth being raised for some years and lowered for others as MoSPI incorporated several methodological changes to measure the size of the Indian economy more accurately and comprehensively. But the magnitude of some revisions left economists puzzled, with even Raghuram Rajan, then the Governor of the Reserve Bank of India, saying the central bank found it “hard to see the economy as rollicking” in 2013-14 after growth for that year was raised to 6.9% (later revised to 6.4%) from 4.7% as per the 2004-05 GDP series.
The latest GDP series will also see major changes, the most crucial of which will be how nominal GDP is adjusted for price changes to arrive at real GDP. According to economists, India’s real GDP growth of 7.8% in April-June 2025 and 8.2% in July-September 2025 was likely overstated due to MoSPI’s use of the so-called single-deflator method.
To find a sector’s Gross Value Added (GVA), the value of inputs it uses is subtracted from the value of output it produces. This is GVA in current prices, or nominal terms. To find real GVA, the output and input values must be adjusted by their respective inflation rates – inputs by the rate at which their prices have changed and outputs by the change in prices consumers face. This is called double deflation.
However, MoSPI currently does this only for agriculture and mining and quarrying sectors. For others, it uses the same rate of inflation for both input and output prices, or the single-deflator method. This method is problematic when input and output prices change at different rates. When input prices are falling or rising at a slower pace than output prices, use of the single-deflator method can lead to overestimation of GVA, GDP, and growth – as was the case in 2025. And when input prices are rising at a faster pace than output prices, it can lead to underestimation of GVA and GDP.
The new GDP series will, in a major move, not use the single-deflator method at all. Deflators will also be used at a more granular level, allowing for more accurate measurement of real GDP growth.
Some other changes in the new series include the use of new sources of data and surveys (GST, e-Vahan, Annual Survey of Unincorporated Sector Enterprise, Periodic Labour Force Survey, among others). Further, by integrating national accounts data with Supply and Use Tables – which show how different goods and services are supplied by domestic industries and imports and how they are distributed between different intermediate or final uses, including exports – MoSPI is hoping to minimise the ‘discrepancy’ component which arises when GDP measured by the more reliable production approach does not match with the GDP calculated via the expenditure method. Large discrepancies can lead to significant revisions in GDP growth rates in the future while making it difficult to understand what is driving growth.
A key requirement for a new GDP series is a ‘normal’ year that will be used as the base year. However, the last decade has been repeatedly interrupted by disturbances: demonetisation in 2016, GST rollout in 2017, the coronavirus pandemic in 2020, and a sharp economic recovery in 2021. As such, 2022-23 presented the first opportunity to MoSPI.
But when will the next revision take place? According to statistics ministry officials, not before 2030. “Under normal conditions”, the ministry’s endeavour is to update GDP every five years, as done globally. However, the years immediately after 2029-30 are an opportune moment for the next GDP revision for another reason.
The 2008 System of National Accounts (SNA 2008) – the international statistical standard for national accounts data – is currently being used by India and other countries to compile GDP. Last year, the United Nations Statistical Commission adopted an updated version of these norms, called SNA 2025.
“The overall aim is to have a coordinated implementation process with the desired outcome of all countries implementing the standards within an implementation window of 2029-2030 as a target,” the United Nations Statistics Division said in its implementation strategy document.
“India plans to shift to SNA 2025 in its next base year revision,” the aforementioned MoSPI official said.
