Harvard University | Columbia University | Yale University | University of Paris | New York University | Stanford University | Princeton University | University of Cambridge | University of Pennsylvania | University of Michigan | University of Chicago | University of California, Berkeley | University of Toronto | Cornell University | University of Oxford | University of London | University of Oslo | Cambridge University | University of Southern California | McGill University | Johns Hopkins University | Northwestern University | University of California | Brown University | University of Queensland | University of Minnesota | University of Washington | University of Notre Dame | University College London | Duke University |
He also held short-term visiting positions at the Victoria University of Wellington, New Zealand (1993), University of Bucharest, Romania (1998), University of Pernambuco in Recife, Brazil (1999), and The Bernoulli Institute (at EPFL) in Lausanne, Switzerland (2004).