Stephen Choi, a leading young corporate and securities law expert at Boalt Hall School of Law at the University of California at Berkeley, has accepted a permanent offer from the law school at New York University, where he is presently visiting. When word got out last Spring that Choi might be moveable, several top law schools expressed interest. That NYU prevailed must be particularly welcome news in Washington Square, given the hit their corporate faculty took last year when Henry Hansmann returned to Yale after only a year and Robert Daines moved to Stanford.