Traditionally, classical economists viewed economic growth as a mechanical function of adding more workers, more land, and more machines. But when applied to the modern global economy, this breaks down. Physical investment, such as a factory, is subject to the unforgiving law of diminishing returns. A country can double its stock of tractors or computers, but it also needs to double its roll of technically capable workers to operate them. In 1992, economists Gregory Mankiw, David Romer and David Weil isolated human capital — the collective blend of education, health and specialised skills — as its own independent, standalone factor of production.
Human capital — not geography, culture or natural resources — now explains why some nations become wealthy while others remain stagnant. In the old models, a country that invested four times more heavily than another in physical machinery only ended up twice as rich. But the Mankiw-Romer-Weil model proves that when high physical-capital investment is multiplied by high human-capital investment, it creates a compounding impact, a 16-fold leap in wealth per worker. Furthermore, growth theorists Robert Lucas and Paul Romer demonstrated that human capital possesses a unique economic edge: It does not suffer from diminishing returns. An engineer who invents a better piece of software creates an asset that can be used by every computer in the world simultaneously. Human capital creates increasing returns to scale. This explains why modern, knowledge-based economies can grow indefinitely. Physical capital builds the floor of an economy, but human capital is the engine that pulls the ceiling upward.
This is not just an academic construct. It is the fact behind the 20th century’s greatest economic miracles. In 1953, South Korea was a war-torn nation with an adult literacy rate of only 20 per cent. It possessed no oil, no minerals, and negligible physical wealth. The state treated education policy as its core industrial policy. It eliminated illiteracy to feed light manufacturing in the 1960s, expanded vocational technical schools to supply heavy industries in the 1970s, and flooded universities with science and technology resources in the 1980s. Today, it stands as a global innovation juggernaut.
Singapore faced an equally grim start upon its sudden independence in 1965. Lacking even domestic water supply, then Prime Minister Lee Kuan Yew noted that the island’s only asset was its people. The city-state ruthlessly aligned its schooling system with the exact technical requirements of foreign multinationals. Later, rather than letting skills become obsolete, it pioneered continuous, state-funded adult retraining. China, the ultimate manufacturing leviathan, too followed a human-capital playbook. Before Deng Xiaoping opened up the economy in 1978, decades of public investment had already secured widespread basic literacy and rural health care. When global supply chains arrived, they not only found cheap labour but also a highly disciplined, literate workforce capable of reading blueprints and executing complex assembly. Beijing then executed the largest higher-education expansion in human history, graduating over 10 million students annually today, heavily weighted towards engineering, to lead the world in electric vehicles and green technology.
Here the trajectory has been the opposite. The country put the cart of higher education before the horse of secondary education, spawning a world-class educated elite. Its premier technical institutes and business schools supply the chief executive officers of Silicon Valley and the engineers powering sophisticated global capability centres in Bengaluru. But an economy of 1.4 billion people cannot ride to upper-middle-income status on the back of a few million tech professionals. While billions of dollars are being funnelled into physical infrastructure, basic foundational learning and public health languish. The data from the World Bank’s human capital index consistently highlights that children born in India today will grow up to be only half as productive as they could be in conditions of complete education and full health.
If India is to transform its much-vaunted “demographic dividend” from a ticking time bomb into an economic engine, it must dramatically pivot. First, public funding must aggressively target foundational childhood health and education in early years. Second, vocational training should be integrated directly into the schooling cycle, shifting the educational metric to employability. Third, the state must forge deep, institutional partnerships between industries and training centres, dynamically updating the curricula. These are the bare minimum steps. But then these ideas are all known and have been articulated many times by experts. The question is: Are we serious enough to implement them with results and accountability? India can continue down its current path, celebrating headline-grabbing GDP figures driven by government spending on capital-intensive projects and elite service sectors. But until New Delhi closes the vast human-capital deficit, even moving into a higher-middle-income category will be a struggle.
The writer is cofounder of www.moneylife.in and a trustee of the Moneylife Foundation; @Moneylifers 
 "India's economic growth slowed in the April-June quarter of the current financial year (Q1FY25) compared to that in the fourth quarter of the previous year on a high base, according to estimates from various agencies.")