Thursday, November 19, 2015

Remembering Herbert E. Scarf of Yale, Great Economist and Operations Researcher - Rest in Peace

This past Tuesday, while teaching my Transportation and Logistics class at the Isenberg School of Management, a class that I love to teach, we were discussing the importance of identifying conditions that guarantee uniqueness of equilibria. I had presented an extended model of transportation network equilibria and we were analyzing it qualitatively.

In order to emphasize to the students  the importance of uniqueness (I was focusing on link flows),  I related to the students a wonderful workshop that I had spoken at, which took place at Stanford University.  The workshop was entitled: Applied General Equilibrium Workshop and it took place March 11-12, 1988. My presentation was  (I checked on my cv): "Variational inequalities and the computation of large-scale equilibria."

I mentioned to my students how exciting it was for me to see George Dantzig there, Curtis Eaves, the Nobel laureate Kenneth Arrow, and also Herbert Scarf.  My dissertation advisor at Brown University, Stella Dafermos, was also there and we were the only two females that had been invited to take part. Strangely enough, I even recall now, although the workshop took place back in 1988,  what Kenneth Arrow was wearing (one of his favorite plaid shirts),  and Herb Scarf's shoes, which, for some reason, impressed me because they were stylish and looked so comfortable. I recall them as being beige Rockport shoes.  The audience, when I spoke about Wardrop's two principles of travel behavior, thought I had said "Wardrobe equilibrium", which Stella and I thought was very funny.

At the workshop we also discussed conditions for uniqueness, which was judged to be a very important property for policy makers when it came to equilibrium problems and a Harvard economics professor was especially avid on this point. The workshop was an intellectual delight and one of the last times that I was with my advisor at a conference since she passed away in 1990.

On Tuesday, when I was reminiscing and sharing the above in my class, I had no idea until I got back to my office and then saw the news, that Professor Herbert E. Scarf had passed away and only two days ago! 

INFORMS produced a fine tribute to Scarf  and the INFORMS President, Ed Kaplan of Yale, recently shared the sad news with all of us. I told my students today of Scarf's passing.

Scarf I remember as being very stately, pleasant, and elegant and had a very warm and welcoming way about him. I was in awe of him because of his book, "Computation of Economic Equilibria," with T. Hansen, which was published by Yale University Press in 1973. Scarf was an economist and also a great contributor to operations research.

In my first book, "Network Economics: A Variational Inequality Approach", which was published in 1993 as the first book in the series: Advances in Computational Economics, I cite Scarf's book in chapter 7, which is on Walrasian Price Equilibrium.  That book is my most highly cited publication according to Google Scholar.

Scarf was a true visionary and realized the importance of algorithmic tools to solve complex equilibrium problems. We have much to thank him for and he will be missed.