GST rollout boosted state tax revenues, buoyancy, says India Ratings
A study by India Ratings (Ind-Ra) found that state tax revenue buoyancy rose sharply after the rollout of the Goods and Services Tax (GST), based on a comparison of 26 states across the pre-GST and post-GST periods.
Average state tax buoyancy rose to about 2.9 during FY18–FY26 (the post-GST period), compared with about 0.6 during FY14–FY17 (the pre-GST period).
Manipur, Nagaland, Goa, Maharashtra and Sikkim recorded the highest tax buoyancy among states in the post-GST period, a marked change from the pre-GST top five of Meghalaya, Bihar, Nagaland, Chhattisgarh and Manipur.
The GST taxpayer base expanded from about 6.7 million registered taxpayers in 2017 to about 16.5 million by May 2026, reflecting wider compliance and formalisation.
The study also noted that tax collection growth has slowed since FY22, touching a five-year low in FY26, attributed to a higher base effect from the post-pandemic recovery, slower nominal GDP growth, and rate/exemption changes under the recent round of GST reforms.
Tax Buoyancy — Concept and Interpretation
Tax buoyancy measures the responsiveness of tax revenue growth to growth in the underlying tax base or GDP, capturing both the automatic effect of economic growth and the effect of policy/administrative changes (unlike tax elasticity, which nets out discretionary policy changes). A buoyancy value below 1.0, in the absence of rate changes, typically signals administrative inefficiency or leakage, while a value at or above 1.0 indicates efficient, more-than-proportionate revenue mobilisation.
Key Details
- Tax buoyancy = (percentage change in tax revenue) ÷ (percentage change in GDP or the tax base), over a given period.
- Unlike buoyancy, tax elasticity strips out the impact of discretionary changes (new taxes, rate revisions) to isolate the "automatic" responsiveness of the tax system.
- A buoyancy figure above 1 for many states post-GST (2.9 on average across the sample) indicates that state tax collections grew faster than the base, credited to simplification, digitisation (e-way bills, e-invoicing), and a wider formal tax net.
- Economists have separately noted that overall economic growth of 6.5–7% typically requires an aggregate tax buoyancy in the 1.2–1.5 range to sustain fiscal space — underscoring how far above trend the post-GST buoyancy figures are.
The Ind-Ra finding that buoyancy rose from ~0.6 (pre-GST) to ~2.9 (post-GST) is presented as evidence that GST's design — a broader base, input tax credit chain, and digital compliance trail — improved the responsiveness of state revenues to economic activity, beyond what the pre-GST patchwork of state VAT, sales tax and entry taxes achieved.
101st Constitutional Amendment Act, 2016 and the GST Council
The Goods and Services Tax was introduced through the Constitution (101st Amendment) Act, 2016, which inserted Article 246A empowering both Parliament and state legislatures to levy GST, and created the GST Council under Article 279A to recommend rates, exemptions, and administrative matters. GST subsumed a range of central and state indirect taxes (excise duty, service tax, VAT, sales tax, entry tax, entertainment tax, among others) into a single destination-based tax, effective July 1, 2017.
Key Details
- Presidential assent to the 101st Amendment: September 8, 2016; GST rollout: July 1, 2017.
- Article 246A gives states concurrent power to legislate on GST (subject to Article 279A Council recommendations), a departure from the earlier division of tax powers between Union and states under the Seventh Schedule.
- The GST Council (Article 279A) is chaired by the Union Finance Minister, with all state Finance/nominated Ministers as members; recommendations historically operated by a weighted voting formula (Centre: one-third weightage; states: two-thirds combined).
- A GST compensation mechanism guaranteed states a 14% annual revenue growth over a base year, funded through a compensation cess, for the first five years of GST (2017–2022) to protect states against transition revenue loss.
The buoyancy gains documented by Ind-Ra are the tax-performance outcome of the constitutional and institutional design created by the 101st Amendment; the initial five-year compensation guarantee was meant to bridge states through the transition until buoyancy of the kind now observed took hold.
Fiscal Federalism — Why State-Level Tax Performance Matters
Under India's fiscal federalism architecture, states depend on their own tax revenue, devolution recommended by the Finance Commission, and GST collections (CGST/SGST/IGST settlement) to fund expenditure. Divergent tax buoyancy across states — smaller/North-Eastern states now outperforming larger, more industrialised states — has implications for horizontal equity and the design of future devolution formulae.
Key Details
- GST has three components: CGST (Centre), SGST (State), and IGST (inter-state supplies, apportioned between origin and destination states) — a destination-based consumption tax structure.
- North-Eastern and smaller states (Manipur, Nagaland, Sikkim) improving in buoyancy is significant because their narrower manufacturing/consumption base historically meant weaker own-tax revenue and greater dependence on central transfers.
- Larger states like Maharashtra and Karnataka retained their top positions in absolute GST revenue share even as buoyancy rankings shifted, while Gujarat overtook Uttar Pradesh for the third-highest revenue share in the post-GST period.
- The Finance Commission (currently the 16th Finance Commission) separately determines vertical (Centre-state) and horizontal (inter-state) tax devolution shares, factoring in criteria like income distance, population, and tax effort — a distinct exercise from GST buoyancy but related to overall state fiscal capacity.
Improved buoyancy in smaller/NE states, set against a slowdown in aggregate GST growth to a five-year low in FY26, will likely feature in future Finance Commission and GST Council deliberations on compensation, devolution, and further rate rationalisation.
- Average state tax buoyancy: ~0.6 (FY14–FY17, pre-GST) versus ~2.9 (FY18–FY26, post-GST).
- Top 5 states by post-GST tax buoyancy: Manipur, Nagaland, Goa, Maharashtra, Sikkim.
- Top 5 states by pre-GST tax buoyancy: Meghalaya, Bihar, Nagaland, Chhattisgarh, Manipur.
- GST registered taxpayer base: ~6.7 million (2017) to ~16.5 million (May 2026).
- GST rollout date: July 1, 2017; enabling law: Constitution (101st Amendment) Act, 2016 (assented September 8, 2016).
- GST Council constitutional basis: Article 279A; GST levy basis: Article 246A.
- Compensation cess guarantee to states: 14% annual revenue growth, for five years from FY18 to FY22.
- Tax collection growth noted at a five-year low in FY26, per the study.