BERKELEY, Calif. — On Jan. 1, South Korea takes over the Group of 20 chairmanship from the United Kingdom. Korea is not the first emerging market to chair the G20, but it is the first to do so since the global financial crisis. And it is the first to do so since the G20 emerged as the steering committee for the world economy.

G20 chairs can have considerable influence. They coordinate the group's work, they organize its meetings. Like most committee chairs, they have significant agenda-setting power.

During Britain's G20 chairmanship, Gordon Brown had a clear agenda. He saw the G20 as a vehicle for building consensus on coordinated monetary and fiscal stimulus measures and financial regulation. He also viewed it as a forum to address problems created for the poorest countries by the global financial crisis. And he used the chairmanship to elicit commitments to resist protectionism.