ive found everywhere that its on the behalf of literature, but after a 5 sec google of his acceptance speech i found that its on behalf of those who survived and their children, as he states, "It frightens me because I wonder, do I have the right to represent the multitudes who have perished? Do I have the right to accept this great honor on their behalf? ... I do not." and then continues on to how he accepts it in the name of the jewish survivors and how he has identified with them.