Jay Forrester, SM '45
Computing pioneer founded system dynamics
Jay Forrester, professor emeritus of management, may be best known for his 1940s work on magnetic core memory, which ushered in the age of real-time digital computing. This breakthrough freed the machines from reliance on untrustworthy and costly glass tubes and transformed them into reliable, quick-calculating powerhouses. And that was just the first of his intellectual breakthroughs. Forrester also created system dynamics, a discipline that applies a computer systems perspective to human behavior in fields ranging from medicine to economics. In fact, he views system dynamics as “a much more enduring contribution to humanity than magnetic storage.”
Forrester was an original member of the MIT group that built the Whirlwind digital computer, a feat documented in the new book Bright Boys: The Making of Information Technology. The Whirlwind evolved into the Semi-Automatic Ground Environment (SAGE) air defense system that protected North America in the 1950s and 1960s. By 1956, he was a tenured professor at the MIT Sloan School of Management, where he developed computer simulations to analyze and illuminate how social and physical systems change over time–the essence of system dynamics.
“System dynamics forms a foundation for understanding almost every academic subject, allowing students to move easily from one field to another,” Forrester says. In economics, he adds, “the patterns we see using system dynamics are much different, much larger, than the business-cycle-related issues you read about in the papers and provide an explanation for the Great Depression of the 1930s and the present enduring recession.”
Today, semiretired at 92, he continues to work on emerging ideas. In particular, he is proposing system dynamics as the basis for a new kind of K-12 education and as a better way to understand economics and, therefore, to develop more effective policies and business models.
“I entered MIT for one year of graduate education, and I haven’t found my way out yet,” says Forrester, who earned a bachelor’s degree in 1939 at the University of Nebraska. His sons have continued his MIT legacy. Ned Forrester ‘75, SM ‘76, studied electrical engineering, and Nathan Forrester, PhD ‘82, focused on system dynamics. His daughter, Judith, followed another family tradition, living on the cattle ranch in Nebraska where Forrester grew up. His wife of 64 years, Susan Swett Forrester, passed away in June.
Over the years, Forrester’s accomplishments have won him numerous awards, including the IEEE Computer Pioneer Award in 1982 and the National Medal of Technology in 1989. He lives in Concord, Massachusetts.