Ashbery is considered the most influential American poet of his time. Oxford University literary critic John Bayley wrote that Ashbery "sounded, in poetry, the standard tones of the age." Langdon Hammer, chair of the English Department at Yale University, wrote in 2008, "No figure looms so large in American poetry over the past 50 years as John Ashbery" and "No American poet has had a larger, more diverse vocabulary, not Whitman, not Pound." Stephanie Burt, a poet and Harvard professor of English, has compared Ashbery to T. S. Eliot, calling Ashbery "the last figure whom half the English-language poets alive thought a great model, and the other half thought incomprehensible".