Jean Tirole, a French economist whose theories about the behavior of large companies underpin modern antitrust regulation, won this year’s Nobel Prize in Economic Sciences.

It was the first time in more than 30 years that the prize has been given for the study of regulation, a topic that has moved well beyond academia since the financial crisis.

At the core of Mr. Tirole’s work are models, often densely mathematical, that describe monopolies, oligopolies and markets. But he also has ranged widely across industries, among them payment cards and telecommunications, to produce studies of their particular function and dysfunction.

Among his prescient works were examinations,in the late 1990s of the importance of banks having access to assets that can be quickly turned into cash. Regulators around the globe are today putting in place rules that require banks to hold more such liquid assets.

The Royal Swedish Academy of Sciences on Monday cited Mr. Tirole’s analysis of monopolies and oligopolies in honoring the Toulouse School of Economics professor.