Arthur Pentland Dempster (October 8, 1929 â January 30, 2026) was an American mathematician who was professor emeritus in the Harvard University department of statistics. He was one of four faculty members composing the department when it was founded in 1957.
Dempster received his B.A. in mathematics and physics (1952) and M.A. in mathematics (1953), both from the University of Toronto. He obtained his Ph.D. in mathematical statistics from Princeton University in 1956. His thesis, titled The two-sample multivariate problem in the degenerate case, was written under the supervision of John Tukey.
Dempster died on January 30, 2026, at the age of 96.
Among his contributions to statistics are the initial theory that was expanded into the DempsterâÂÂShafer theory with Glenn Shafer, and the expectation-maximization (EM) algorithm.
Dempster was a Putnam Fellow in 1951. He was elected as an American Statistical Association Fellow in 1964, an Institute of Mathematical Statistics Fellow in 1963, and an American Academy of Arts and Sciences Fellow in 1997.