Thomas C. Schelling, a former longtime professor at Harvard University and the Kennedy School of Government whose insights on group and personal behaviors spanned many disciplines and were credited with reducing the risk of nuclear war, died Tuesday in his Bethesda, Md., home. The Nobel laureate in economics was 95.
Wresting game theory out of the abstract realm, Professor Schelling used it to explain a spectrum of behaviors, from everyday decisions such as how patrons choose theater seats to existential actions such as how superpowers cobble together strategies to prevent nuclear annihilation.
While his books influenced a generation of policy makers, students, and theorists, Professor Schelling’s guidance directly shaped strategies in the Kennedy and Johnson administrations.
“Tom Schelling is a titan, and it is not the slightest exaggeration to say that his remarkable scholarship has made the world a safer and better place,” David T. Ellwood said in 2005, when Professor Schelling was awarded the Nobel and Ellwood was dean of the Kennedy School.
The Nobel committee agreed, saying his “insights have proven to be of great relevance for conflict resolution and efforts to avoid war.”
Professor Schelling saw himself as “a social scientist interested in conflict and cooperation.” In his teachings, research, writings, and consulting, he sought to apply game theory — the mathematical study of decision-making amid conflict — to ascertain what actions individuals or institutions would take to secure the best outcomes for themselves.
His book “The Strategy of Conflict,” published in 1960, is considered a seminal synthesis of how game theory can be used, whether in a chess match, by organized crime, or for nuclear deterrence. In a 1978 book, “Micromotives and Macrobehavior,” his applications included a study on how group dynamics can, at times inadvertently, lead to neighborhood segregation and white flight.
He also explored conflicts within oneself, such as the battle fought by a smoker who promises to quit, only to continually reach for one “last” cigarette.
The economist, himself then a smoker, knew well the struggle. Among the many Harvard groups he led was the university’s Institute for the Study of Smoking Behavior and Policy.
His language in his books was lauded for its lucidity, his ideas for their compelling qualities.
“Schelling is the world’s foremost strategic thinker about social situations and human behavior,” economist and onetime Harvard colleague Richard Zeckhauser wrote. “He is an acknowledged expert in such areas as global warming (which involves many players), arms control and deterrence (few players), and smoking behavior (one player).”
No subject fired his intellect and curiosity more than seeking ways to prevent a surprise nuclear attack. His application of game theory formed the foundation for what would be known as the US strategy of mutually assured destruction. To explain the apocalyptic standoff between the United States and the Soviet Union, Professor Schelling reached back to his love of Western movies as a child.
“The ‘equalizer’ of the Old West (the ‘six-shooter’) made it possible for either man to kill the other; it did not assure that both would be killed,’’ he said, according to a 2012 account for the Harvard Kennedy School by his biographer and former student, Robert Dodge. “The advantage of shooting first aggravates any incentive to shoot. As a survivor might put it, ‘He was about to kill me, so I had to kill him in self-defense.’
“But if both were assured of living long enough to shoot back with unimpaired aim, there would be no advantage in jumping the gun and little reason to fear that the other would try it.”
Much of his research in the late 1950s was done at the RAND think tank, a nexus of civilian and military consultants.
“Once the vital game of survival in a nuclear age challenged Schelling’s attention, mere economics could no longer contain him,” wrote Paul Samuelson, the longtime Massachusetts Institute of Technology professor and first US winner of the Nobel Prize in Economics.
As an adviser, Professor Schelling would frequently travel to the nation’s capital.
“In the 1960s, no academic figure exemplified the romance of Harvard in Washington better than Schelling,’’ wrote Boston Globe columnist David Warsh in 1990. “It was in Kennedy’s Camelot that Schelling really burst upon the Washington scene, commuting for his day-a-week consulting job on Friday, and during Lyndon Johnson’s years the economist-cum-strategist was everywhere, advising the best and the brightest in the Defense Department and the National Security Council.’’
He was credited with helping develop President Kennedy’s robust stance that checked Soviet aggression and defused the Berlin crisis in 1961. He was instrumental in the creation of a hot line between Washington and Moscow in 1963.
Robert McNamara, who taught at Harvard before becoming Kennedy’s secretary of defense, wrote that Professor Schelling’s “view permeated civilian leadership under Kennedy . . . . to a remarkable degree.”
Professor Schelling looked upon war as bargaining, in which competing sides are influenced by incentives and deterrents, promises and threats, and the abundance or dearth of information. He developed war games that instructed Robert Kennedy and Henry Kissinger, among others, on how to prevent a crisis from spiraling into a catastrophe.
“Those who read Schelling and participate in his games learn a general principle: In any interactive situation it is vitally important to look at matters from the side of the other party,’’ Zeckhauser said. “The other-people’s-shoes approach is often recommended by soft-hearted promoters of compromise. The core principle, however, is that by understanding the other party’s perspective you will improve your comprehension of the situation dramatically and will come out better yourself. This is an important lesson for hard hearts as well.”
Professor Schelling, who was, as Warsh put it, “a tough-minded peacenik,’’ had an advisory role in Stanley Kubrick’s antiwar classic: “Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb.’’ Kubrick had come to Professor Schelling’s Harvard office after reading his article “Meteors, Mischief and War.”
In the 1964 movie, the Soviets deploy a ‘‘doomsday device’’ that would detonate in the event of an attack. Professor Schelling used a precept of game theory to elucidate the film’s central joke: ‘‘One obvious point in the Strangelove movie was that the Soviet doomsday thing was not a deterrent . . . when the other side did not know in advance that it existed.’’
A native of Oakland, Calif., Thomas Crombie Schelling received a bachelor’s degree in economics from the University of California, Berkeley. He became immersed in the matters of the Cold War, working in Europe for the Marshall Plan and in Washington with the Truman administration. He graduated with a doctorate in economics from Harvard in 1951.
He taught at Yale University before working at the RAND Corp. In 1958, Professor Schelling joined Harvard University. After mandatory retirement in 1990, he taught another dozen years at the University of Maryland.
“Tom was the most lucid, most incisive, most insightful mind among the stellar band of founding fathers of Harvard’s Kennedy School,” said former Kennedy School dean Graham Allison.
On Harvard’s campus, he built a reputation for his ability to pace and rapidly talk through a seemingly intractable problem with his students, linking disparate threads from everyday encounters. “No matter how complicated an argument he would weave, Schelling never dropped a strand, and the product was consistently complete, compelling, and beautiful,” Harvey Fineberg, former dean of the Harvard School of Public Health, once said.
Professor Schelling’s first marriage, to Corinne Saposs, ended in divorce. He leaves his wife, Alice Coleman Schelling of Bethesda; four sons from his first marriage, Andrew of Boulder, Colo., Tom of Ashland, Daniel of Salt Lake City, and Robert of Putney, Vt.; two stepsons, David Coleman of Mountain View, Calif., and Robert Coleman of Portland, Ore.; a sister, Nancy Dorfman of Lexington; 12 grandchildren; and three great-grandchildren.
Continuing his studies into his 90s, he was planning to give two talks on climate change, Zeckhauser, who knew Professor Schelling for 58 years, told the Associated Press.
‘‘He had as clear and incisive a mind as anybody you would ever meet,’’ Zeckhauser said, ‘‘and did not have a modicum of pretense about him.”