Ten years later, in 1978, the University of Chicago economics faculty admitted their mistake and gave him a Ph.D. for his earlier work.
[1][2] Clarke worked in public policy at the city/regional (Chicago), State, Federal and international levels.
He served as special assistant to the Secretary of the Treasury (George P. Shultz) and chief economist at A. I.
During the mid-1970s, he was heavily involved in airline and trucking deregulation and most recently in oversight of Federal regulatory activities affecting transportation.
[2] Clarke's 1994 TRB paper (with Wayne Brough and Nicolaus Tideman), entitled "Airport Congestion and Noise, Interplay of Allocation and Distribution" illustrates the potential applicability of the Vickrey–Clarke–Groves mechanism to problems of transportation congestion.