Professor Calyampudi Radhakrishna Rao is an Eberly Professor Emeritus of Statistics at Pennsylvania State University. Before his retirement he served as Director of the Centre for Multivariate Analysis at Pennsylvania State University and as an Adjunct Professor at the University of Pittsburgh. Professor Rao presently lives with his daughter, Prof Tejaswini Rao, Professor of Nutrition at City University of New York, Buffalo, and he celebrated his 100th birthday on 10 September 2020. Professor Rao received an honorary doctorate degree from the University of Pretoria in 2002.

He has been a world leader in statistical science for the last seven decades. His research, scholarship and professional services have had a profound influence on the theory and applications of statistics. Technical terms such as Cramer-Rao inequality, Rao-Blackwellization, Rao’s score test, Fisher-Rao theorem, and Rao distance and orthogonal arrays (which are used extensively in industry) appear in all standard books on statistics. The results associated with these terms have been extensively used in engineering and other disciplines. Two of his papers appeared in Breakthroughs in Statistics in the last century.

Rao was awarded an MA degree in mathematics by Andhra University and an MA degree in statistics by Calcutta University before he began doing research at the Indian Statistical Institute (ISI), one of the leading institutes in the world. He was later invited to work on a project at Cambridge University that required the statistical methodology he had developed at the ISI. Based on the work he did, Prof Rao earned PhD and ScD degrees from Cambridge University. To date, he has received 38 honorary doctorates from universities in 18 countries on six continents around the world. He held several important positions, as the Director of the ISI, Jawaharlal Nehru Professor and National Professor of India, University Professor at the University of Pittsburgh, and Eberly Professor of Statistics at Pennsylvania State University.

As Head and later Director of the Research and Training School at the ISI for over 40 years, Prof Rao developed research and training programmes and produced outstanding students which ‘put India not far from the centre of the statistical map of the world’. During this period, he also directed the training programmes at the International Statistical Educational Centre which led to the development of statistics in the Southeast Asian region, for which he received the prestigious Mahalanobis Award from the International Statistical Institute.

For his pioneering contributions to statistical theory and applications, Prof Rao received numerous awards. He is a Fellow of the Royal Society. He was elected to the National Academy of Sciences (USA), the American Academy of Arts and Sciences, the Indian National Science Academy, the Lithuanian Academy of Sciences and the Third World Academy of Sciences. He was made an honorary member of the International Statistical Institute, the International Biometrics Society, the Royal Statistical Society, the Finnish Statistical Society, the Portuguese Statistical Society, the Institute of Combinatorics and its Applications and the World Innovation Foundation, and Honorary Life Fellow of King’s College, Cambridge. He has been the President of the International Statistical Institute, the Institute of Mathematical Statistics (USA) and in the International Biometrics Society.

Prof Rao also received numerous medals: the Wilks Medal of the American Statistical Association, the Army Wilks Medal, the Guy Medal in Silver of the Royal Statistical Society, the Meghnad Saha Medal and the Srinivasa Ramanujan Medal of the Indian National Science Academy, the JC Bose Gold Medal of the Bose Institute and the Mahalanobis Centenary Gold Medal of the Indian Science Congress. Furthermore, he received the Bhatnagar Award of the CSIR of India.

Prof Rao was honoured by the president of the USA with the prestigious National Medal of Science with the citation, ‘for his pioneering contributions to the foundations of statistical theory and multivariate statistical methodology and their applications, enriching the physical-biological, mathematical, economic and engineering sciences’.

The Government of India honoured him with the second-highest civilian award, the Padma Vibhushan (the highest is the Bharat Ratna, of which Dr Nelson Mandela was a recipient), for ‘outstanding contributions to science and engineering/statistics’, and also instituted a cash award in his honour, ‘to be given once in two years to a young statistician for work done during the preceding three years in any field of statistics’.

In 2001, the University of Cyprus honoured Dr Nelson Mandela and Prof CR Rao with honorary doctorate degrees on the same platform. Dr Mandela remarked on the occasion, ‘now I realized, if I want to be fit, I must do statistics half an hour every day’.

TOP 10 CITATIONS

1. In an article entitled ‘The statistical century’ published in the Royal Statistical Society News (Vol 22, Jan 1995), the distinguished statistician Bradley Efron stated:

Karl Pearson’s famous chi-square paper appeared in the spring of 1900, an auspicious beginning to a wonderful century for the field of statistics. The first half of the century was the golden age of statistical theory, during which our field grew from ad hoc origins, similar to the current state of computer science, into a firmly grounded mathematical science. Men of the intellectual caliber of Fisher, Neyman, Pearson, Hotelling, Wald, Cramer and Rao were needed to bring statistical theory to maturity.

2. A review of CR Rao’s book, Linear statistical inference and its applications, by the famous statistician WG Cochran in the Journal of the Franklin Institute states the following:

CR Rao would be found in almost any statistician’s list of the five outstanding workers in the world of Mathematical Statistics today. His book represents a comprehensive account of the main body of results that comprise modern statistics theory.

3. From the preface to the special issue of the Journal of Quantitative Economics in honour of CR Rao:

Dr Rao is a very distinguished scientist and highly eminent statistician of our time. His contributions to statistical theory and applications are well known, and many of his results, which bear his name, are included in the curriculum of courses on statistics at bachelor’s and master’s levels all over the world. He is an inspiring teacher and has guided the research work of numerous students in all areas of statistics. His early work had greatly influenced the course of statistical research during the last four decades. One of the purposes of this special issue is to recognize Dr Rao’s own contributions to econometrics and acknowledge his major role in the development of econometric research in India.

4. From the preface to the special issue of the Journal of Statistical Planning and Inference on ‘Characterizations of probability distributions and related stochastic models’ dedicated to CR Rao on his 75th birthday:

CR Rao is unquestionably one of the architects of ‘Modern Characterization Theory’. His pioneering research and inspirational leadership have had a major influence on the developments in the area. Indeed largely due to the efforts of the people like CR Rao, the area has now acquired a healthy status of being one of the most active and important research areas … CR Rao’s work in characterization theory has led to several keywords in the area, associated with his name.

 S Karlin, a mathematician who won the President’s medal:

CR Rao is among the worldwide leaders in statistical science over the last five decades. His research, scholarship, and professional service has had a profound influence on the theory and applications of statistics and is incorporated into standard references for statistical study and practice.

CR Rao is not only a highly creative theoretician but was attracted and labored with many data sets in health, biology, psychology and social sciences.

6. S Amari, a renowned mathematician from Japan:

Dr Rao is a great scholar beyond the framework of statistics, which he himself has founded. It is a big surprise that his influence has been effective and has played a great role for more than half a century to produce fruitful developments in several scientific disciplines.

The idea of connecting statistics and differential geometry was too early at that time (1945). However, after nearly half a century, Rao’s idea has been developed to become one of the most active and important topics in information sciences, connecting statistics, information theory, control and statistical physics.

7. The Institute of Combinatorial Mathematics and its Applications elected CR Rao as an honorary member with the citation:

As the world’s leading expert in statistical design theory

8. Press release by the Government of India on Prof Rao’s appointment as National Professor (limited to 12 at any time):

The government has appointed CR Rao, an eminent statistician, as National Professor, Professor Rao is an outstanding and creative thinker in the field. He was appointed by Professor Mahalanobis as a full-fledged professor of the Indian Statistical Institute at the early age of 29 in recognition of his creativity. Dr Rao succeeded him as Secretary of the Institute and later its Director.

9. The Times of India dated 31 December 1988 chose CR Rao as one of the top ten of modern India, considering all disciplines and the impact of the work done by each scientist. The list includes Nobel Laureates S Chandrasekhar, H Khurana and CV Raman. 

10. Citation upon Prof Rao’s being awarded an Honorary DSc by the Ohio State University.

Prof Yadavalli, the Head of the Department of Industrial and Systems Engineering in the Faculty of Engineering, Built Environment and Information Technology at the University of Pretoria comments: ‘Among the international community of scholars, you are widely acknowledged as one of the world’s foremost statisticians. In the complex realms of statistics and higher mathematics, your research and scholarly writing have opened new doors of understanding. The statistical theories and applications which bear your name attest to the fundamental contributions you have made to your field and to the larger body of humanity’s knowledge. Numerous honours and awards have followed in tribute to an unusually distinguished and productive life of inquiry. You have earned the highest accolade of all, the esteem of your peers throughout the world of scholarship.’

On the occasion of Prof Rao’s 100th birthday, the University of Pretoria wishes him a happy birthday