Gallery owner Larry Gagosian on the art world’s “blood sport”

He’s been called “the biggest art dealer in the history of the world.” With 18 galleries around the globe, Larry Gagosian has more exhibition space than most museums. He talks with correspondent Anthony Mason about his estimated billion-dollar-a-year business; New York’s competitive art world; spotting the talent of a young Jean-Michel Basquiat; and why, at age 79, he thinks resting is “overrated.”