C. R. Rao
Rao in 2012
Calyampudi Radhakrishna Rao

(1920-09-10)10 September 1920
Died22 August 2023(2023-08-22) (aged 102)
CitizenshipIndian (until 1995)
American (1995–2023)[3]
EducationAndhra University (MA)
University of Calcutta (MA)
King's College, Cambridge (PhD, DSc)
Known forCramér–Rao bound
Rao–Blackwell theorem
Orthogonal arrays
Score test
AwardsPadma Vibhushan
National Medal of Science (2001)
S. S. Bhatnagar Prize
Guy Medal (Silver 1965, Gold 2011)
International Prize in Statistics (2023)
Scientific career
FieldsMathematics and Statistics
Thesis Statistical Problems of Biological Classifications  (1948)
Doctoral advisorRonald Fisher
Doctoral students

Calyampudi Radhakrishna Rao FRS (10 September 1920 – 22 August 2023) was an Indian-American mathematician and statistician.[4] He was professor emeritus at Pennsylvania State University and Research Professor at the University at Buffalo. Rao was honoured by numerous colloquia, honorary degrees, and festschrifts and was awarded the US National Medal of Science in 2002.[5] The American Statistical Association has described him 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, demography, biometry, and medicine."[5] The Times of India listed Rao as one of the top 10 Indian scientists of all time.[6]

In 2023, Rao was awarded the International Prize in Statistics,[7] an award often touted as the "statistics’ equivalent of the Nobel Prize".[8] Rao was also a Senior Policy and Statistics advisor for the Indian Heart Association non-profit focused on raising South Asian cardiovascular disease awareness.[9]

Early life

C. R. Rao was the eighth of the ten children born to a Telugu family[1] in Hoovina Hadagali, Bellary, Madras Presidency, Britain ruled India (now in Vijayanagara, Karnataka, India). His schooling was completed in Gudur, Nuzvid, Nandigama, and Visakhapatnam, all in the present state of Andhra Pradesh.[2] He received an MSc in mathematics from Andhra University and an MA in statistics from Calcutta University in 1943.[5] He obtained a PhD degree at King's College, Cambridge, under R. A. Fisher in 1948, to which he added a DSc degree, also from Cambridge, in 1965.[citation needed]


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Rao first worked at the Indian Statistical Institute and the Anthropological Museum in Cambridge. Later he held several important positions, as the Director of the Indian Statistical Institute, Jawaharlal Nehru Professor and National Professor in India, University Professor at the University of Pittsburgh and Eberly Professor and Chair of Statistics and Director of the Center for Multivariate Analysis at Pennsylvania State University.[10]

As Head and later Director of the Research and Training School at the Indian Statistical Institute for a period of over 40 years, Rao developed research and training programs and produced several leaders in the field of Mathematics. On the basis of Rao's recommendation, the Asian Statistical Institute (ASI), now known as the Statistical Institute for Asia and Pacific, was established in Tokyo to provide training to statisticians working in government and industrial organisations.[11]

Among his best-known discoveries are the Cramér–Rao bound and the Rao–Blackwell theorem both related to the quality of estimators.[12] Other areas he worked in include multivariate analysis, estimation theory, and differential geometry. His other contributions include the Fisher–Rao theorem, Rao distance, and orthogonal arrays. He was the author of 14 books and published over 400 journal publications.

Rao received 38 honorary doctoral degrees from universities in 19 countries around the world and numerous awards and medals for his contributions to statistics and science. He was a member of eight National Academies in India, the United Kingdom, the United States, and Italy. Rao was awarded the United States National Medal of Science, that nation's highest award for lifetime achievement in fields of scientific research, in June 2002. He was given the India Science Award in 2010, the highest honour conferred by the government of India in a scientific domain. In 2013, he was nominated for the Nobel Peace Prize, along with Miodrag Lovric[13] (Editor) and Shlomo Sawilowsky, for their contribution to the International Encyclopedia of Statistical Science.[14] He was most recently honoured with his 38th honorary doctorate by the Indian Institute of Technology, Kharagpur, on 26 July 2014 for "his contributions to the foundations of modern statistics through the introduction of concepts such as Cramér–Rao inequality, Rao–Blackwellization, Rao distance, Rao measure, and for introducing the idea of orthogonal arrays for the industry to design high-quality products."

Rao was the President of the International Statistical Institute, Institute of Mathematical Statistics (USA), and the International Biometric Society. He was inducted into the Hall of Fame of India's National Institution for Quality and Reliability (Chennai Branch) for his contribution to industrial statistics and the promotion of quality control programs in industries.

The Journal of Quantitative Economics published a special issue in Rao's honour in 1991: "Dr. Rao is a very distinguished scientist and a 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 in statistics at bachelor's and master's level all over the world. He was 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 recognise Dr. Rao's own contributions to econometrics and acknowledge his major role in the development of econometric research in India."

Areas of research contributions


Rao died in Buffalo, New York on 22 August 2023, aged 102.[15][16][17][18]

Obituaries describing his professional contributions and impact on the society have been published in the IMS Bulletin [1] and Nature [2].

Awards and medals

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In his honour

Selected publications

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Edited volumes


Collected works[edit]


  1. ^ a b Nielsen, Frank (1 December 2016). "Interview with Professor Calyampudi Radhakrishna Rao". Amstat News.
  2. ^ a b Prakasa Rao, B. L. S. (10 September 2014). "C. R. Rao: A life in statistics" (PDF). Current Science. Retrieved 17 February 2020.
  3. ^ "The Numberdars". The Times of India. 1 October 2011. Archived from the original on 23 March 2016.
  4. ^ "The Numberdars". Times Crest. 1 October 2001. Archived from the original on 23 March 2016. Retrieved 14 March 2016.
  5. ^ a b c "Statisticians in History: Calyampudi R. Rao". American Statistical Association. 30 November 2016. Archived from the original on 3 March 2016. Retrieved 4 October 2009.
  6. ^ "C.R.Rao in News". C.R.Rao Advanced Institute of Mathematics, Statistics and Computer Science.
  7. ^ "International Prize in Statistics". www.statprize.org. Retrieved 10 April 2023.
  8. ^ Biswas, Atanu (8 April 2023). "C.R. Rao wins top statistics award – a look back at his pioneering work". The Hindu. ISSN 0971-751X. Retrieved 10 April 2023.
  9. ^ "Indian Heart Association". Indian Heart Association Webpage. Retrieved 27 April 2015.
  10. ^ DasGupta, Anirban (27 February 2024). "C.R. Rao: Paramount statistical scientist (1920 to 2023)". Proceedings of the National Academy of Sciences of the United States of America. 121 (9): e2321318121. doi:10.1073/PNAS.2321318121. PMC 10907269. PMID 38377193.
  11. ^ "Profile". C.R.Rao Advanced Institute of Mathematics, Statistics and Computer Science.
  12. ^ "Telugu professors do homeland proud". The Times of India. 3 July 2010. Retrieved 22 October 2016.
  13. ^ "Miodrag Lovric Home Page". Archived from the original on 10 March 2014. Retrieved 2 June 2017.
  14. ^ https://www.ime.usp.br/~abe/lista/pdfcFHNhReNSn.pdf [bare URL PDF]
  15. ^ "Indian American Mathematician CR Rao No More". Deccan Chronicle. 23 August 2023. Retrieved 23 August 2023.
  16. ^ "Renowned Indian Mathematician C.R Rao passes away in America". The Hans India. 23 August 2023. Retrieved 23 August 2023.
  17. ^ "Legendary statistical scientist CR Rao dies". 23 August 2023.
  18. ^ "C.R. Rao, Amherst resident and winner of statistics' 'Nobel Prize,' dies at 102". 23 August 2023.
  19. ^ "C.R. Rao Receives the India Science Award". Eberly College of Science, Penn State University. 19 October 2010. Archived from the original on 26 September 2015. Retrieved 28 December 2013.
  20. ^ "The previous winners of the Award are Professor C.R. Rao (India) in 2003..." "Archived copy". Archived from the original on 1 January 2014. Retrieved 1 January 2014.((cite web)): CS1 maint: archived copy as title (link)
  21. ^ "NRI Award, Sardar Patel Award, Sardar Ratna, Pravasi Bharatiya Award, International Award". www.sardarpatelaward.org.
  22. ^ a b "Padma Awards" (PDF). Ministry of Home Affairs, Government of India. 2015. Archived from the original (PDF) on 15 October 2015. Retrieved 21 July 2015.
  23. ^ "Recipients of Honorary Degrees". University of Calcutta. Archived from the original on 30 December 2013.
  24. ^ "Road to be named after Prof. C.R. Rao". The Hindu. 10 September 2009. Archived from the original on 13 September 2009. Retrieved 6 May 2012.

Further reading


For the Cramér–Rao inequality and the Rao–Blackwell theorem see the relevant entries on

For Rao contribution to information geometry

Photograph of Rao with Harald Cramér in 1978