Legendary statistical scientist CR Rao

Aug 26,2023: C Radhakrishna Rao, one of India’s greatest mathematicians and statisticians, died in the US at the dawn of August 23, about two weeks before his 103rd birthday.
Known as Dr Rao to his colleagues and students, the former director of Indian Statistical Institute (ISI) had hit the headlines earlier this year after he was awarded the International Prize in Statistics, which many consider equivalent to the Nobel Prize.
Rao studied mathematics at Andhra University and obtained a degree with top honours. Recognising his talent, his father encouraged him to study higher mathematics.
After his father’s death in 1941, Rao was called to Calcutta for an interview pertaining to his job application to the Indian military. A chance meeting with a person who knew of the ISI brought Rao to the Presidency College where Prasanta Chandra Mahalanobis had established ISI (before it was moved to its own campus). By speaking with some faculty members and workers, Rao felt that ISI was the right place for him.
In an interview in 2013, Rao stated: “I went back to Visakhapatnam and told my mother [that he would like] to get admitted to ISI for training in statistics, and it would cost me Rs 30 a month to stay in Kolkata. She said she would raise the money somehow and that I should go to Kolkata to join ISI. I travelled to Kolkata with `30 in my pocket and joined ISI on 1 January 1941.”
Rao’s seminal contributions have been in areas of statistics that deal with designing an experiment for efficient extraction of information and testing scientific hypothesis using the results of the experiment.
After he had obtained his MA, Rao was offered a technical apprenticeship in ISI. He also began to teach statistics at Calcutta University. In 1944, he derived a seminal result with which his name is associated — the Cramer-Rao bound. In 1945, he proved a result that is now known as the Rao-Blackwell theorem.
Often, we need to obtain knowledge of an unknown feature of a population like, say, the average monthly income of an Indian. Data can be collected only from a small number of people. From these data, one can obtain an approximate knowledge of monthly income. There are several ways of obtaining estimates from data, but the method proposed by Rao, and two years later by David Blackwell, results in highly reliable estimates.
He went to Cambridge and obtained a PhD under Ronald Fisher, a founder of modern statistical science. During his PhD, he discovered a method, now known as Rao’s Score Test, which is used in all branches of science.
Rao returned to India in 1948 and became a professor in ISI at 28; in 1964, he was appointed its Director. After his retirement from ISI, he moved to the US. In 1982, he established the Center of Multivariate Analysis at the University of Pittsburgh. He joined the Pennsylvania State University in 1988. In 2007, the University of Hyderabad opened the C R Rao Advanced Institute of Mathematics, Statistics and Computer Science. Around 2010, Rao moved to the University of Buffalo at Amherst. He published his last scientific work in his 100th year.
Rao was hugely creative. He used to categorise creativity in two kinds.
“At its highest level, it is the birth of a new idea or a theory which is qualitatively different from and not conforming to or deducible from any existing paradigm, and which explains a wider set of natural phenomena than any existing theory. There is creativity of another kind at a different level, of a discovery made within the framework of an existing paradigm but of immense significance in a particular discipline.”
Rao had excelled in creativity of both kinds.
C. R. Rao was born to a Telugu family in Hadagali, Bellary, Madras Presidency (now in Karnataka), India. His schooling was completed in Gudur, Nuzvid, Nandigama, and Visakhapatnam, all in the present state of Andhra Pradesh. He received an MSc in mathematics from Andhra University and an MA in statistics from Calcutta University in 1943. He obtained a Ph.D. degree at King’s College in Cambridge University under R. A. Fisher in 1948, to which he added a DSc degree, also from Cambridge, in 1965.
The Indian American statistician was recently awarded International Prize in Statistics, which is statistics’ equivalent of the Nobel Prize. The most distinguished exponent of the subject, Calyampudi Radhakrishna Rao’s monumental work across several branches of statistics and its applications, is noteworthy.
He joined the ISI as a student when it was set up by Dr. P.C. Mahanobilis when statistics as a subject was still in its early years and yet to be taught as a distinct subject at the post-graduate level.
He was sent by Dr. Mahalanobis to Cambridge University, United Kingdom to use certain statistical techniques for anthropological analysis, and from where he earned a doctorate under the supervision of Ronald Fischer, among the pioneers of the field.
On returning to the ISI in India, where Dr. Rao spent the next 40 years of his career, he conceived and established several undergraduate and graduate programmes in statistics and was instrumental in establishing several bureaus of the Indian Statistical Institute in various States.
Dr. Rao was also a member of several government committees for the development of national statistical systems, statistical education and research in India. He served as chairman of the Committee on Statistics (1962-69), chairman of the Demographic and Communication for Population Control (1968-69), chairman of the Committee on Mathematics, Atomic Energy Commission, AEC (1969-78), member of the Committee on Science and Technology, COST (1969-71).
After his retirement, Dr. Rao moved to the United States and worked at several universities. Former U.S. President George Bush conferred on him the National Medal of Science. He was awarded India’s highest honours the Padma Bhushan and Padma Vibhushan in 1969 and 2001, respectively.
Reference: Partha P Majumder(The Indian Express),Deccan Chronicle,The Hindu