Jean Tirole has won the 2014 Nobel Prize in economics for his work on large firms and regulation.
The highly coveted Sveriges Riksbank award in economic sciences dedicated to the memory of Alfred Nobel carries prize money of 8m Swedish krona (£775,000).
This year's prize was focused on "taming powerful firms", particularly in industries with just a few key players.
French economist Tirole, who is the scientific director of industrial economics at Toulouse University, was praised by the judges for his analysis of market power.
The awarding committee said:
Jean Tirole is one of the most influential economists of our time. He has made important theoretical research contributions in a number of areas, but most of all he has clarified how to understand and regulate industries with a few powerful firms.
His book, Theory of Corporate Finance, published in 2005, was given an award for excellence by the Association of American Publishers.
Via telephone Tirole said he was "so moved" by receiving the award he might not be able to answer any questions but he would try.
Last year, the award was split between Eugene Fama, Lars Hansen and Robert Shiller for their work in predictions. Or as the committee puts it "for their empirical analysis of asset prices".