James M. Buchanan, a Nobel Prize-winning economist from George Mason University, whose opposition to deficit spending and support of a balanced-budget amendment helped shape conservative economic and political thought, died Jan. 9 at a hospital in Blacksburg. He was 93.

The death was confirmed by a nephew, Jeff Whorley, who said he could not cite a specific cause. He noted that his “Uncle Buck” had traveled to Europe in the past year and lived alone on a working farm outside Blacksburg.

Since 1956, Dr. Buchanan had spent most of his career in Virginia, teaching at the University of Virginia and Virginia Tech before joining the faculty at George Mason in 1983. He won the Nobel Prize in 1986 for being a key architect of the school of economic thought known as public choice.

In simplified form, Dr. Buchanan applied the principles of the economic marketplace to politics. He argued that politicians and government officials — like other participants in an economic system — acted in their own self-interest. Since the policymakers’ goal was to be reelected or maintain power, they did not always act in the best interest of the public, or at least of public finances.

Lawmakers routinely voted for programs popular with their constituents, Dr. Buchanan maintained, but they were reluctant to ask for corresponding tax increases.

James M. Buchanan in his office at George Mason University in Fairfax, Va., on June 26, 1985. (Charles K. Crockett/THE WASHINGTON POST)

“Their natural proclivity is to spend more and not tax,” he explained to Time magazine in 1986. By refusing to make a choice between taxing and spending, the politicians ended up driving the economy into a cycle of ever-spiraling budget deficits.

“His big contribution,” Gary Hufbauer, senior fellow at the Peterson Institute for International Economics, said Wednesday, “is that he got our profession to think of government policymakers not as platonic philosophers but as interested parties in their own right who are furthering their own views, at least some extent.”

Dr. Buchanan and his onetime colleague, Gordon Tullock, outlined the “public choice” model in their 1962 book “The Calculus of Consent,” which became a major theoretical basis for conservative and libertarian economic thinkers.

Their view represented a stark departure from the long-prevailing economic views of John Maynard Keynes, who held that deficit spending was a useful tool for advancing the public good through government programs.

“Keynesian economics turned the politicians loose,” Dr. Buchanan wrote in 1978.

Dr. Buchanan was also a longtime advocate for a constitutional amendment requiring a balanced budget, saying politicians would not stop spending unless forced.

“There’s a natural proclivity for them to create deficits unless they are constrained by some moral rule or some constitutional rule,” he told The Washington Post in 1986.

Sen. Phil Gramm (R-Tex.), a sponsor of the Gramm-Rudman-Hollings Act of the 1980s, once described Dr. Buchanan as the first economist “to bring to bear the basic logic of economics to public-policy decision-making.”

Some scholars were not as receptive to his economic solutions, calling them simplistic and unoriginal. But Dr. Buchanan, who had disdain for what he called the “Eastern academic elite,” said his ideas reflected “simple applications of common sense that the academics all forget about.”

James McGill Buchanan Jr. was born Oct. 3, 1919, in Murfreesboro, Tenn. His grandfather was a Tennessee governor in the 1890s, but Dr. Buchanan grew up in rural poverty “without indoor plumbing, electricity, radio, television, or air travel,” he wrote in an autobiographical essay.

He graduated from Middle Tennessee State University in 1940 and received a master’s degree in economics from the University of Tennessee in 1941. During World War II, he served on the staff of Navy Adm. Chester W. Nimitz, commander of the Pacific fleet.

Dr. Buchanan received his doctorate in economics in 1948 from the University of Chicago, long a center of market-oriented economic thought.

He taught at the University of Tennessee and Florida State University before going to U-Va. in 1956 as head of the economics department. He founded a center for the study of political economy at Virginia, then joined the faculty at Virginia Tech in 1969.

Although he had been affiliated since 1983 with George Mason — and was the Fairfax-based university’s first Nobel laureate — Dr. Buchanan continued to live on his 400-acre farm outside Blacksburg, where he raised cattle and grew vegetables.

His wife of 60 years, Anne Bakke Buchanan, died in 2005. Survivors include two sisters.

In 2007, Dr. Buchanan retired from George Mason’s Center for Study of Public Choice — which he had founded at Virginia Tech — but he continued to deliver occasional lectures and work on projects until his death.

His other books included “Fiscal Theory and Political Economy” (1960), “The Limits of Liberty” (1975), “Freedom in Constitutional Contract” (1978), “Liberty, Market and State” and a 10-volume collection of other writings.

Even Dr. Buchanan’s staunchest admirers admitted that he was forbidding and hardly had a warm personality.

“I want a private sphere in which I am protected, where nobody can invade,” he told the Chicago Tribune in 1986. “I don’t feel the need to be a part of a community or a team.”