Nathan Keyfitz far exceeded his cohort’s average life expectancy having passed away in 2010 at the age of 96.
He had three challenging careers, during which he profoundly influenced the demographic profession. His first career as a statistician began at the Canadian Dominion Bureau of Statistics. At age 46 he began his academic career at the University of Toronto. And his unusually creative third career began after he retired from academia at age 70.
In 1934, Keyfitz graduated with a B.Sc. in Mathematics from McGill University in the depths of the Great Depression when jobs were scarce in Canada. He took his first job at the Canadian Dominion Bureau of Statistics where he spent 23 years, first as a research statistician and later a senior statistical advisor, using his mathematical skills to analyze unemployment statistics and demographic trends of the Canadian population. According to Keyfitz’s fascinating memoir (see http://keyfitz.org/nathan/memoir), the Bureau’s water cooler is the site of his first encounter with Beatrice Orkin; Beatrice later became Keyfitz’s wife for 70 years of marriage and the mother of their two children, Barbara and Robert. In 1951, Keyfitz obtained his PhD in Sociology from the University of Chicago, with a dissertation on the fertility of the Canadian population. This launched his second career.
At age 46 Keyfitz accepted his first academic post at the University of Toronto. This was followed by academic appointments at the Universities of Montreal, Chicago, U.C. Berkeley, Harvard and Ohio State. Near the end of his Chicago stay, he published his widely influential Introduction to the Mathematics of Population. In 1977, he published Applied Mathematical Demography, an innovative book that illuminates the many ways that simple mathematical tools provide insights into complex population issues; the third edition was published in 2005, 28 years after the first!
Keyfitz’s academic career formally ended with his retirement at age 70 from two institutions – Harvard and Ohio State – which marked the beginning of his third career. In “retirement” he became a consultant to Harvard’s Institute for International Development and the head of the population program at the International Institute for Applied Systems Analysis in Austria. He continued to be in constant demand as a consultant and advisor both domestically and internationally, building upon his earlier worldwide travels. Keyfitz took his first international trip at age 38 to Burma to help with their census. Subsequent trips included Indonesia, India, Sri Lanka, Argentina, Russia, China and many other countries. Along the way, he taught himself numerous languages, typically by reading foreign newspapers during his commuting time. The issues he confronted in his travels informed many of the research questions he subsequently addressed. His interests and publications increasingly focused on issues of environmental and food security, population and sustainable development, the ethics of consumption, climate change, and poverty. But he continued his academic pursuits in aging, social security and pension systems both domestic and international, still with a strong interest in Canada.
With his creativity and keen understanding of the interplay of population models and data, Keyfitz is often considered to be the founder of the field of mathematical demography. However, his interests were so broad, his analytical abilities so formidable, and his publications so vast that he has influenced the intellectual history of many disparate fields, both methodological and substantive. He stood at the forefront of population research for more than half of a century. He is sorely missed by his friends, colleagues, and former students.