Sir Roy George Douglas Allen, CBE, FBA (1906 - 1983) was an English economist and mathematician.
R G D Allen was born in Worcester and educated at the Royal Grammar School Worcester, from which he won a scholarship to Sidney Sussex College, Cambridge. He gained a First Class degree in Mathematics and was awarded a Wrangler scholarship.
He became a lecturer at the London School of Economics (LSE) later becoming Professor of statistics. He wrote many papers and books on mathematical economics including the famous paper on A Reconsideration of the Theory of Value published in Economica in 1934 with Sir John Hicks. Other books include: Mathematical Analysis for Economists (1938), Statistics for Economists (1949), Mathematical Economics (1956), and Macroeconomic Theory (1967).
He was Knighted in 1966 for his services to economics and became president of the Royal Statistical Society. He was also treasurer of the British Academy of which he was a fellow (FBA).
Amongst his many great achievements and contributions to economics is his concept of the "partial elasticity of substitution" set out in his famous 1938 book. He was one of the first economists to use mathematics in economics and taught a whole generation of famous economists.
He became a fellow of Sidney Sussex, Cambridge and died in 1983.