Ragu Raj Bahadur
Hira Lal Koul

• Ragu Raj Bahadur was born on April 30, 1924 in Delhi, India. After completing his undergraduate education in the University of Delhi, he secured his Ph.D. in statistics from the University of North Carolina, Chapel Hill in 1950, under the guidance of Herbert Robbins. In the 1950s he served as a Professor at ISI, Calcutta, and from 1961 onwards, he was a Professor of Statistics at the University of Chicago, where he retired in 1992 and passed away as a Professor Emeritus on July 7, 1997, at the young age of 73. Bahadur was a fellow of the American Academy of Arts and Sciences, the Institute of Mathematical Statistics, the International Statistical Institute, the Indian National Sciences Academy and the Indian Academy of Sciences. He was an excellent lecturer and the 1974 Wald Lecturer of the IMS and served as the President of the IMS in 1974-75. Bahadur made several foundational and seminal contributions to statistics. His papers are extremely well written and transparent. His paper on `On Fisher's bound for asymptotic variances' provides an elegant proof of the fact that in the absence of regularity conditions the Fisher information bound for the asymptotic variance of CAN estimate of a parameter may be violated on a set of parameter values having Lebesgue measure zero. In connection with his work on Bahadur efficiency he developed in depth large deviation analysis of the log-likelihood ratio statistic. One of his most cited paper is the paper bearing the title `A note on quantiles in large samples' in Ann. Math. Statist. 37, 577--580, 1966, where he obtained an almost sure first order approximation for the sample quantile. This work was later refined by Jayant Ghosh and Jack Kiefer. It is now known as the Bahadur- Ghosh-Kiefer representation. Bahadur's work with T.W. Anderson on solving binary classification problems with applications to statistical classification and engineering is known as the Anderson-Bahadur algorithm. Steve Stigler, the Ernest De Witt Burton Distinguished Service Professor of Statistics at the University of Chicago, says that ``"Raj was one of the architects of the modern theory of mathematical statistics. His work, which was characterized by a singular depth and elegance, changed the way statisticians think about statistical information at a fundamental level. People from all over the world made pilgrimages to see him." To honor his legacy, the IISA has instituted Bahadur Lecture Series since 2017. At the forthcoming IISA 2022 meeting in Bengaluru, Professor Soumendra Lahiri will be the Bahadur Lecturer. Professor Lahiri made fundamental and pioneering contributions to bootstrap methodology and statistical inference at large, making him a very appropriate person to deliver this lecture. Past Bahadur Lecturers were Arup Bose (Mumbai, 2019), Alexander Belloni (2018, Gainesville) and J. Sethuraman (2017, Hyderabad).

  

  Ragu Raj Bahadur