R.V. Ramamoorthi passed away on November 22, 2023, at the relatively young age of 73. Known as RVR to many, he was on the faculty at Michigan State University for 37 years. He retired voluntarily in 2019 and moved with his wife Deepa (whom he married in 1985) to Bengaluru, India for personal reasons. He was receiving treatment at a local hospital in Bengaluru for respiratory problems and died from complications.

RVR was born in Palakkad, which is now in the state of Kerala in South India, but he was Tamil speaking. His father, R.A. Vaideeswaran, was an administrative officer with US AID, and his mother, Mangalambal, was a housewife. After finishing his Masters at Utkal University in Bhubaneswar, he joined the Indian Statistical Institute (ISI) in Kolkata for his PhD. He completed his dissertation under the supervision of Professor Jayanta Ghosh and graduated in 1981. He spent a year as a Visiting Assistant Professor at Florida State before moving to Michigan State in East Lansing in 1982. He was on the faculty in the Department of Statistics and Probability from 1982–2019, first as a visitor, then joining the tenure-track faculty in 1984, and rising up through the ranks to Full Professor.

Over the course of his career, RVR held visiting appointments at several institutions, including the universities of Pavia, Rome, and Bocconi in Italy, ISI (Kolkata, Delhi, Bengaluru), Indian Institute of Science, and Chennai Mathematical Institute. He served on several editorial boards; most notably, he provided extensive service to Sankhyā in several capacities.

RVR’s research interests were theoretical. He was an ardent Bayesian and was interested in the Foundations of Statistics throughout his career. His PhD dissertation was on Pairwise Sufficiency and Bayes Sufficiency in Undominated Experiments. He continued to study concepts of sufficiency, ancillarity, and Bayesian inference. He was active until the end, and he completed his last paper dealing with “Doob’s theorem on posterior consistency” just a few weeks before he was hospitalized. He was preparing to teach a course next semester on Graphical Models at the Chennai Math Institute.

RVR’s most well-known research contribution is his book Bayesian Nonparametrics, co-authored with J.K. Ghosh, and it is widely considered to be a tour de force. The book’s reviewers noted that it presented a “comprehensive treatment” of the area with “theoretical underpinnings of nonparametric priors in a rigorous yet extremely lucid style … It is indispensable to any serious Bayesian. It is bound to become a classic in Bayesian nonparametrics.”

Despite his theoretical research, RVR had broad interests and was well informed about emerging directions in the field. He fully recognized the importance of applications and appreciated the need to recruit colleagues with diverse interests. RVR was an unusual academic in these days of “publish or perish” philosophy and emphasis on research funding. He marched to the beat of his own drum, worked only on problems that interested him, and was selective in publishing. But he was a deep thinker, and his contributions were always significant and insightful.

On a personal level, RVR led a simple life and was very non-materialistic. In keeping with his disdain for ceremonies and rituals, he had asked that his body and organs be donated for scientific research. He was a voracious reader with diverse interests, and he could carry a conversation on pretty much any topic. He also had a great sense of humor. One of us [VN] will always remember the joke he heard from RVR: “The most interesting stories must be complex. They should have a real part and an imaginary part.” It was a lot of fun to spend an evening with him, a glass of whiskey in hand, sharing stories and talking about people and the profession. He was especially fond of his time as a graduate student and the opportunities he had to get to know ISI’s distinguished faculty at the time as well as many legendary visitors. He was also a great mentor to students, having served as Graduate Director, and he supported the careers of many junior faculty members.

RVR leaves behind his wife Deepa, and siblings, nieces, and nephews, both in India and the US. He will be dearly missed by all of them, as well as by his many friends.

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Written by Vijay Nair, University of Michigan, Ann Arbor, USA; and B.V. Rao and Rajeeva Karandikar, Chennai Mathematical Institute, India