In addition to being a great economist, Marty was an institution builder. He was the early driving force behind the rise of the NBER, he led the development of empirical public finance as a respected field, and also very early on he pushed health care economics, both through his leadership at the NBER and through his own work and mentorship. He always was reaching out to help others, and Larry Summers, Jim Poterba, David Cutler, Raj Chetty, and Jason Furman were some of those he mentored. The economics of art museums was yet another topic he had a real interest in, and stimulated research in.
Marty also was one of my oral examiners at Harvard, and he asked only excellent questions. I thank him for judging my answers to be good enough.