In the annals of India's scientific and economic history, few figures loom as large as Prasanta Chandra Mahalanobis, the visionary physicist who transformed into the nation's chief statistical architect. His journey from quantum physics to statistics laid the groundwork for India's data-driven policy framework that continues to influence the country's development trajectory.
From Cambridge Physics to Statistical Revolution
Born in 1893 into an intellectually vibrant Brahmo family in Kolkata, Mahalanobis received his early education at Brahmo Boys' School before progressing to Presidency College. His academic pursuits took him to King's College, Cambridge, where he studied physics, setting the stage for an unexpected career turn that would redefine India's relationship with data.
The year 1915 proved pivotal. Having completed his studies at Cambridge, Mahalanobis found his return to India delayed by World War I. This unforeseen circumstance led him to the King's College library, where he discovered Karl Pearson's journal Biometrika. The young Bengali physicist, originally focused on quantum mechanics, found himself captivated by the emerging field of statistics, marking a fundamental shift in his professional orientation.
Building India's Statistical Infrastructure
Returning to India, Mahalanobis began teaching physics at his alma mater, Presidency College, while simultaneously pursuing statistical research. His early work involved analyzing meteorological and anthropometric data, where he innovatively applied statistical methods to practical problems like flood forecasting and crop yield prediction.
By the late 1920s, his reputation had grown sufficiently to establish informal statistical laboratories within Presidency College. Gathering mathematically gifted students and researchers around him, he formed the nucleus of what would become the Indian Statistical Institute (ISI), formally established on December 17, 1931, in a small room within his college quarters.
During this period, Mahalanobis developed his most celebrated theoretical contribution—the Mahalanobis Distance (D²). This sophisticated measure for comparing multivariate datasets brought him international acclaim and remains relevant today in fields ranging from machine learning to biometrics.
The Architect of India's Economic Planning
Mahalanobis's greatest practical achievement came in 1950 with the creation of the National Sample Survey (NSS). At a time when newly independent nations struggled with reliable economic data collection, he pioneered large-scale nationwide sample surveys that provided unprecedented insights into India's economy and society.
His success with the NSS made him an indispensable advisor to the government. In 1954, Prime Minister Jawaharlal Nehru appointed him as honorary statistical advisor and member of the Planning Commission, positioning him to undertake his most ambitious project: designing India's second five-year plan.
The Mahalanobis Model, which formed the plan's backbone, drew inspiration from Soviet planning but adapted it to India's unique circumstances. The model proposed a simple but demanding strategy: India should prioritize investments in heavy capital goods over light consumer goods, sacrificing immediate consumption for long-term industrial capacity building.
Controversies and Lasting Legacy
Despite its ambitious vision, the Mahalanobis Model faced significant challenges. The assumption of a closed economy proved unsustainable, and the massive import requirements for capital goods triggered a foreign-exchange crisis in 1957, forcing painful mid-course corrections.
Economist B.R. Shenoy submitted a Note of Dissent criticizing the plan's excessive size, magnitude of deficit financing, and policy implications. Meanwhile, Mahalanobis's autocratic leadership style bred dissatisfaction, leading to public dissent from colleagues including geneticist J.B.S. Haldane, who resigned citing governance issues at ISI.
Although the Mahalanobis Model was eventually abandoned and India experienced decades of slow growth until 1990s liberalization, the institutions he built have endured. The Indian Statistical Institute, National Sample Survey, and the culture of data-driven policy-making remain foundational to India's modern economic and social policy construction.
Beyond his statistical contributions, Mahalanobis maintained a close friendship with Rabindranath Tagore, whom he met through his marriage to Nirmal Kumari in 1923. He wrote extensively about the poet in Bengali magazine Probashi through his series Rabindra Parichay, demonstrating the breadth of his intellectual engagements beyond statistics and economics.
