New Delhi, Dec. 3 -- India is at the threshold of one of the most promising economic decades in its modern history, yet the hard arithmetic underlying growth reflects a more fragile situation than our headline GDP figures suggest.

Economists apply the Sala-i-Martin framework to break growth down into its core components and ask a simple-yet-powerful question: How much of the rise in output per worker can be attributed to the use of more capital (a single factor of production), and how much can be attributed to India becoming more productive on the whole?

The results from India's growth decomposition between 1990 and 2023 reflect the emergence of a two-pronged challenge: capital deepening is now uneven and no longer accelerating, while t...