Horizontal and Vertical Devolution

In Indian fiscal federalism, horizontal and vertical devolution are the two axes along which the proceeds of centrally collected taxes are shared, and both flow from Article 280 of the Constitution, which establishes the Finance Commission, and Article 270, which defines the divisible pool of taxes to be distributed between the Union and the states. The Finance Commission, constituted by the President every five years (or earlier), is mandated under Article 280(3)(a) to recommend "the distribution between the Union and the States of the net proceeds of taxes which are to be, or may be, divided between them" and "the allocation between the States of the respective shares of such proceeds." The first clause is the constitutional basis of vertical devolution; the second is the basis of horizontal devolution. The divisible pool under Article 270 excludes cesses and surcharges (Article 271) and the proceeds earmarked for specific purposes, a carve-out that has become a central point of friction between the Centre and the states.

Vertical devolution operates as a single percentage figure. The Finance Commission recommends the share of the net divisible pool that the states are collectively entitled to receive, with the remainder retained by the Union. The Fourteenth Finance Commission (2015–2020), chaired by Y. V. Reddy, raised this share sharply to 42 percent, the largest single jump in its history, from the 32 percent recommended by the Thirteenth Commission. The Fifteenth Finance Commission, chaired by N. K. Singh, set the figure at 41 percent in its reports for 2020–21 and for 2021–26, the one-percentage-point reduction reflecting the conversion of Jammu and Kashmir from a state into two Union Territories. Once accepted by the Union government and laid before Parliament, this vertical share determines the aggregate transfer; it does not specify which state receives how much.

Horizontal devolution then divides the states' collective share among the individual states through a formula of weighted criteria. These criteria balance equity (compensating poorer states), efficiency (rewarding fiscal performance), and need (population, area, demographic burden). The Fifteenth Finance Commission's horizontal formula assigned 45 percent weight to income distance, 15 percent to population (using 2011 census data), 15 percent to area, 10 percent to forest and ecology, 12.5 percent to demographic performance, and 2.5 percent to tax-and-fiscal effort. Income distance—the gap between a state's per-capita income and that of the richest state—carries the heaviest weight precisely because it channels larger per-capita transfers to lower-income states, embodying the equalisation principle that underpins the entire exercise.

The contemporary politics of these two axes is sharp. Southern and western states—Karnataka, Tamil Nadu, Kerala, Maharashtra—have protested that the Fifteenth Finance Commission's shift from the 1971 census to the 2011 census for the population criterion penalises states that successfully curbed fertility, a grievance the Commission partly addressed by introducing the 12.5 percent demographic-performance weight. The 2021 memorandum from southern chief ministers, and statements by Tamil Nadu's finance ministry through 2023 and 2024, argued that states generating the largest tax revenues receive proportionally smaller shares. Simultaneously, all states have pressed the Union to curb its reliance on cesses and surcharges, which rose to a substantial fraction of gross tax revenue and lie outside the divisible pool, effectively shrinking the base on which the 41 percent vertical share is calculated. The Sixteenth Finance Commission, chaired by Arvind Panagariya and constituted in late 2023, will submit recommendations covering the period beginning April 2026.

These two mechanisms must be distinguished from grants-in-aid, the third channel of transfer recommended under Article 275 and Article 280(3)(b). Devolution is an untied, formula-based share that states may spend at their discretion; grants-in-aid are often purpose-specific, including revenue-deficit grants, sector-specific grants, and local-body grants routed through panchayats and municipalities under Articles 243-I and 243-Y. Devolution should also be separated from centrally sponsored schemes administered by the erstwhile Planning Commission and now monitored by NITI Aayog, which are conditional, matching-fund transfers outside the Finance Commission's tax-sharing remit. Confusing untied devolution with conditional scheme funding misstates the real fiscal autonomy a state enjoys.

A recurring controversy concerns whether vertical devolution figures translate into actual receipts. Because cesses and surcharges are excluded from the divisible pool, the effective transfer to states has at times fallen well below the headline 41 percent of gross tax revenue. The Comptroller and Auditor General has flagged instances where amounts collected as cesses were not transferred to their designated reserve funds. A further edge case arises with the Goods and Services Tax: GST compensation, governed by the GST (Compensation to States) Act, 2017, ran a five-year guaranteed-revenue regime that ended in June 2022, after which the compensation cess was extended only to service back-to-back loans raised during the pandemic, intensifying state demands for a larger vertical share to offset lost compensation.

For the working practitioner—whether a desk officer in a state finance department, a UPSC General Studies Paper II aspirant, or a researcher modelling intergovernmental transfers—the distinction is operationally indispensable. Vertical devolution sets the size of the pie available to states as a bloc and is the arena of Centre-state bargaining over cesses and the divisible pool; horizontal devolution sets each state's slice and is the arena of inter-state equity disputes over census years and income distance. Reading any Finance Commission report requires holding both axes simultaneously: a generous vertical share can still leave a high-income, low-population state worse off if the horizontal formula weights equity heavily, and the political settlement of cooperative federalism turns on getting both numbers acceptable to twenty-eight states at once.