Thread by @satyanewshi

June 29, is Celebrated as ‘Statistics Day’ in India , recognising the contributions of a man who envisioned & built the foundation for Big Data & Analytics for Nation building almost 7 decades ago ~ Prasanta Chandra Mahalanobis . A 🧵 on his works

Prasanta Chandra Mahalanobis was born on 29 June 1893 in Bikrampur, in undivided Bengal (present day Bangladesh) .The influence of an affluent & educated family background made him naturally gravitated towards academic excellence .

He did his schooling from Brahmo Boys School in Kolkata & then went to Presidency College, Kolkata to study Physics & Maths, where he was taught by stalwarts like Jagadish Chandra Bose, Sarada Prasanna Das & Prafulla Chandra Ray.

Meghnad Saha & Subhas Chandra Bose were his juniors at college. He graduated with a Bachelor of Science degree with honors in Physics in 1912.

Mohalanobis then joined Kings College, Cambridge University in 1913. Here he met renowned mathematician Srinivasa Ramanujan at the university who further fuelled his interest in Maths & Stats.

In London Mahalanobis worked under two eminent Cambridge scientists, C.T.R. Wilson & Sir J.J. Thomson at the Cavendish Laboratory.

During his stay period in London , Mahalanobis came across a statistical journal ‘Biometrika’ , this journal fascinated him & planted the seeds of diverse possibility & utility that statistics can be

In 1915 he returned to India & joined presidency college Physics dept as Assistant Professor
In 1920 he teamed up with a group of like-minded colleagues to form the Indian Statistical Institute (ISI) in a small room in presidency college

While teaching & pursuing his interest in statistics went on in presidency college ,Sir Gilbert Walker a noted British statistician invited him to join Alipore Observatory in Calcutta. From 1922-1926, he served as Director of Meteorology.

In 1922, in his first scientific paper, PC Mahalanobis found a way of comparing and grouping populations using a multivariate distance measure.

In 1936, the Mahalanobis distance became known and was accepted as a measure of distance between a point P and a distribution D. It is widely used in cluster analysis and classification techniques.

In 1933, Mahalanobis founded Sankhyā, the Indian Journal of Statistics. “Sankhyā shows the intimate connection which has existed for more than 3000 years in the Indian mind between adequate knowledge and number.

As we interpret it, the fundamental aim of statistics is to give determinate and adequate knowledge of reality with the help of numbers and numerical analysis”

Tagore treated Mahalanobis as a close confidant, despite an age gap of 32 years. Mahalanobis accompanied Tagore on many of his international visits, mostly in the 1920s.

Mahalanobis helped Tagore immensely in his dream project — the founding of Visva Bharati. He also served as a joint secretary of Visva Bharati for 10 years from the beginning.

He wrote a series of essays titled ‘Rabindra Parichay’ (‘Introduction to Rabindra’) for the prestigious Bengali magazine, Probashi. He also wrote a book, Rabindranath Tagore’s Visit to Canada in 1929.

Subhas Chandra Bose, when he was Congress president, introduced Mahalanobis to Nehru . Bose laid out the importance of National planning in Haripura congress session in 1938

Bose later requested Pandit Nehru to be the chairman of All India National Planning Committee . The roots of planning commission was established

m.thewire.in/article/histor…

Moholanobis most important contributions are related to large-scale sample surveys. He introduced the concept of pilot surveys and advocated the usefulness of sampling methods.

Mahalanobis treated statistics as a “new technology for increasing the efficiency of human effort in the wildest sense”.

His contributions to the subject of statistics brought him international fame. In 1945 he was made a Fellow of Britain’s Royal Society, one of the most prestigious organizations of scientists including a stint as the chairman of the UN Commission on Sampling from 1947 to 1951.

After independence India adopted Soviet Union model to organise its economy - through centralised five-year plans for which detail diversified data from grass root level became imperative

In 1950, Mahalanobis launched an ambitious survey programme to get accurate insights of Indian economy which was named as National Sample Survey

In a 1st of its kind 1833 villages & residential areas were surveyed. This limited but diverse sample collected was used for extrapolating to represent the nation of approximately 360 million people at the time.

As per Hindusthan times “It was biggest and most comprehensive sampling inquiry ever undertaken in any country in the world".

Mahalanobis and his colleagues designed a survey in such a way that it would capture, the vast & diverse set of inputs with accuracy that the policy makers wanted

The sampling staff had to take samples from diverse region of India consisting of 15 languages & 140 local system of measurement criss crossing inhospitable terrains like dense & dangerous forest to snow clad Himalayan passes

The National Sample Survey has consistently yielded fine detail about economic parameters of India, helping assess poverty, employment, consumption & expenditure, to mention few of the indicators

The National Sample Survey generated global interest, Chinese officials sent their statisticians to Kolkata to learn from Mahalanobis’s staff in the 1950s

The ISI served as a model for the American statistician Gertrude Cox, for the organisation of statistical training in the USA.The methods pioneered by it are now used by the World Bank and the United Nations.

As Nobel Prize-winning economist Angus Deaton & co-author Valerie Kozel wrote in 2005: "Where Mahalanobis and India led, the rest of the world has followed, so that today, most countries have a recent household income or expenditure survey.

“Most countries," they continued, "can only envy India in its statistical capacity".

The success of the first Five Year Plan inspired the independent Indian government to think bigger. In the early 1950s, the government made Mahalanobis the country’s first Statistical Adviser

ISI was formally inducted into the process for creating the country’s next Five Year Plan. Mahalanobis wrote the first draft of the plan, based on the Mahalanobis model of centralized planning & rapid industrialization.This became the base for the second Five Year Plan (1956-61).

In order to process Massive data , Mahalanobis wanted computers . He engaged Samarendra Kumar Mitra and Soumyendra Mohan Bose to design & fabricate an analogue computer which could solve linear equations required for regression analysis.

Mitra and Bose had to look for used and discarded parts from junkyards in the city. The result of this effort was India’s first ‘analogue electronic computer’ in 1953.

Mahalanobis used his charm & credibility to influence both rival worlds if West & soviet block to get computers for India .

This resulted in ISI acquiring some of the newest computers, such as the Hollerith Electronic Computer (HEC-2M) designed by Booth for British Tabulating Company & URAL computers from Soviets

A 2nd generation, transistor-based computer was also jointly designed & commissioned by ISI and Jadavapur University. It was named ISIJU-1

Govt of India passed the ISI Act in 1959, recognising the institute as an institute of national importance and a Deemed University. PC Mahalanobis initiated statistics for public use in India.

He was awarded the Padma Vibhushan, one of India's highest honours in the year 1968
On 28th June 1972, just a day before his seventy-ninth birthday, PC Mahalanobis left for his heavenly abode

“No other instance of an entirely homegrown institution in a developing country becoming a world leader in a large field of general interest".~ Nobel laureate in Economics Dr. Abhijit Banerjee on ISI

Former PM Dr Manmohan singh in Mahalanobis’s honour for his contribution to statistics and work at ISI, declared 29 June as the National Statistics Day.