(June 25, 2023) Just before India got its independence, a young man of 26 embarked on a journey from Kolkata to England. Little did he know that the borders that he was transcending would one day leave an indelible mark on the world of statistics. Calyampudi Radhakrishna Rao, popularly addressed as C.R. Rao, went on to become a symbol of the Indian brilliance. At 102, the Samaritan is still serving as an inspiration for Indians and Indian origin people scattered across the globe.
Known for the Cramer-Rao bound (CRB), Rao-Blackwell theorem, orthogonal array, MANOVA, Score test, and many more concepts, the Indian-American statistician is widely credited with shaping the field of statistics into a structured and organised form. His contributions to theory and applications in statistics is highly regarded. Many of his findings are included in the curriculum of bachelor’s and master’s level courses offered in institutions around the world.
The 102-year-old statistician has received the 2023 International Prize in Statistics, the field’s equivalent of the Nobel Prize. The award comes with $80,000 in prize money. Not new to awards and accolades the master statistician with an illustrious career spanning 75 years, is also the recipient of Padma Vibhushan, US National Medal of Science, SS Bhatnagar Prize, and Guy Medal to a name a few.
Explaining the fundamental nature of his work Rao had once stated:
Statistics is not a discipline like physics, chemistry or biology where we study to solve problems in the same subject. We study statistics with the main aim of solving problems in other disciplines.
Childhood in pre-independence era
Born in 1920 in a Telugu speaking family in a small town named Huvina Hadagali in Madras Presidency (now in Karnataka), Rao was the eighth out of the 10 (four girls and six boys) children of his parents. While he and his brothers were sent to school to study, his sisters were not, keeping with the times. They stayed at home to help their mother in household chores.
Rao’s father worked as inspector of police under British rule and had frequent transfers. Rao ended up studying in multiple schools in Gudur, Nuzvid, Nandigama, and Visakhapatnam (all in the present state of Andhra Pradesh) owing to this. He did his MSc in mathematics from Andhra University before moving to Calcutta in search of job, becoming an accidental statistician with the twist of events.
The Accidental statistician
Rao was the first one in his family, including his ancestors, to be interested in science and maths. While he was finishing his master’s in mathematics, the Second World War broke out, and there were not many opportunities for those with a degree in mathematics to get a job. So, he tried to get a job in the military service. “I applied to the Department of Survey, which is sort of a party to any military expedition. I was disqualified because I was too young, and they didn’t want me, but that took me to a place called Calcutta,” he said in an interview with the Journal of Statistical Science.
In Calcutta, he came to learn about the Indian Statistical Institute (ISI) established by Prof PC Mahalanobis. Rao casually visited the place and talked to people there, learned about the new subject ‘statistics’ and enrolled in a course in the institute to understand what it was. Finding it interesting, soon after he went on to do an MA in statistics from Calcutta University.
Upon completion of the course, Rao joined ISI in 1943 working under Mahalanobis, ISI’s founder and director.
The Cambridge Opportunity
While Rao was assisting Prof Mahalanobis, an invitation from Dr Trevor of Cambridge University (CU) landed at ISI to send a research scholar to England for an important study. Taking note of Rao’s acumen, Mahalanobis deputed Rao to go to CU and spend two years (1946–1948) as a paid visiting scholar to undertake statistical work at the Anthropological Museum in Cambridge.
“The new methods developed by me to analyse skeletal data were published in the Journal of the Royal Statistical Society and Biometrika during the forties of the last century,” Rao recalled in an interview conducted by Prof Bera of the University of Illinois. “For my work at Cambridge University (CU), I received the PhD degree from the institution, a few years later,” Dr Rao added.
In Cambridge, he had conducted the statistical research under Prof R A Fisher who is known as the ‘Father of Statistics’. Rao considers Fisher one of his biggest gurus. In the realm of probability, a metric devised by them is popularly known as the Fisher-Rao metric.
Under Fisher’s Tutelage, Rao’s intellectual acumen blossomed and he went on to create a tapestry of statistical brilliance. His breakthrough contributions in multivariate analysis, experimental design, and statistical inference laid the foundation for new frontiers in the field. However, despite embracing a new land, a new culture, and new horizons, the statistical maestro yearning to do good work in his country relocated to India.
From England to India and around the world
He worked at the Indian Statistical Institute (ISI) in Kolkata for 40 years and went on to serve as the director of the institute, raising its stature to the world-class institute that it is today.
Between the early ’50s to the late ’70s, for almost 25 years, Rao spent time at various universities in the United States as a visiting professor, while still working at the ISI. In 1965 he added a DSc degree from Cambridge University to his qualifications.
In an interview he said:
I could have moved to the United States much earlier as I had some offers, but I declined because I thought working at the ISI would enable me to develop statistical research in India. It meant some sacrifice on my part in many ways, but I had the satisfaction of promoting statistical education and research in India at a level comparable to that in any other country.
Path breaking contributions
Rao has left an indelible mark with an impressive body of work comprising 477 research papers published in esteemed journals and 15 influential books. His exceptional contributions have reached far and wide, transcending linguistic boundaries with translations of his book in French, German, Japanese, Mainland and Taiwan Chinese, Polish, Russian, German, Czech, Turkish, and Korean languages. Many of his books have remained prominent textbooks for more than 50 years.
“Statistics is more a way of thinking or reasoning than a bunch of prescriptions for beating data to elicit answers,” says the maestro, whose extensive editorial contributions have further enriched the statistical landscape. As the editor of 39 volumes of the acclaimed ‘Handbook of Statistics’, the Global Indian has provided a comprehensive resource for practitioners.
He has received 38 honorary doctoral degrees from universities in 19 countries across the globe, and has been a member of several national academies in India, the United Kingdom, the United States, and Italy.
Impactful work for India
Rao’s extraordinary life unfolded against the backdrop of a changing India. India was a new nation then and there were immense opportunities to contribute. Rao played a crucial role in setting up statistical bureaus in different states of the country and developed a network of statistical agencies at the district level for collecting data. He worked in close association with the Central Statistical Organization and the National Sample Survey to formulate the national statistical system of India which is regarded as one of the best in the world.
He helped in the designing of the National Sample Survey (NSS) and trained the early generations of official statisticians from India and other parts of the world at ISI. He also helped establish The Asian Statistical Institute (ASI) in Tokyo. The organisation is now known as Statistical Institute for Asia and the Pacific and provides training to statisticians working in government and industrial organizations.
Impacting diverse fields
The American Statistical Association has described Rao as a living legend, whose work has influenced not just statistics, but has had far reaching implications for fields as varied as economics, genetics, anthropology, geology, national planning, and demography. His methodologies have guided policymakers, offering data-driven insights to informed decisions with far-reaching consequences.
His work on biometry and medicine have empowered researchers and clinicians to analyse complex biomedical data, facilitating advancements in medical research, disease diagnosis, and treatment. Rao is associated as senior policy and statistics advisor with the non-profit, Indian Heart Association, which raises cardiovascular disease awareness among the South Asian community.
Through his multidisciplinary approach and relentless pursuit of excellence, Professor C.R. Rao has transcended the boundaries of statistics and is still empowering researchers and practitioners to unlock new insights, make informed decisions, and drive progress in their respective fields. As Rao rightly puts it, “All knowledge is in the final analysis, history. All sciences are, in the abstract, mathematics and all methods of acquiring knowledge are essentially statistics.”
In his honour:
- Ministry of Statistics and Programme Implementation (MoSPI), Government of India has established Prof. C.R. Rao National Award
- University of Hyderabad established C.R. Rao Advanced Institute of Mathematics, Statistics and Computer Science (AIMSCS) to promote research in maths, statistics and their applications to varied fields
- The road from IIIT Hyderabad passing along University of Hyderabad has been named Prof. C.R. Rao Road
- The Pennsylvania State University has established C. R. and Bhargavi Rao Prize in statistics