BLACKSBURG, Va. — Nobel laureate James M. Buchanan Jr., whose theories explored the political world through the same hard lens applied to economics, has died. He was 93.

Buchanan’s sister confirmed that Buchanan died Wednesday in Blacksburg, Va., where he lived.

Buchanan was a pioneer in public choice theory, which states that actors in the political world are motivated by the same self-interest that applies to those in the economic marketplace.

He won the Nobel for economics in 1986, when Buchanan’s theories had gained favor in the Reagan administration.

He founded the Center for Study of Public Choice at George Mason University, where he was professor emeritus.

The center’s director, Alex Tabarrok, said Buchanan’s work breathed life into the dry world of economics and brought a steely, real-world outlook to political science.

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