David Blackwell

The citation reads as follows:

The John von Neumann Theory Prize for 1979 is awarded to David Blackwell for his outstanding work in developing the theory of Markovian decision processes, and, more generally, for his many contributions in probability theory, mathematical statistics, and game theory that have strengthened the methodology of operations research and management science.

In the area of Markovian decision processes Blackwell, in a remarkable series of papers published between 1961 and 1966, put the theory of dynamic programming on a rigorous mathematical footing. He introduced new techniques of analysis and established conditions for the existence of optimal and stationary optimal policies. Particularly noteworthy are his studies of the effect of varying the discount rate and his introduction of the important concepts of positive and negative dynamic programs. Virtually all of the subsequent developments in this field are based on these fundamental papers.

In other areas, Blackwell's early work with Arrow and Girshick helped lay the foundations for sequential analysis, and his subsequent book with Girshick systemized the whole field of statistical decision theory, to the great benefit of a generation of mathematical statisticians. The famous Rao-Blackwell theorem on statistical estimation led to a practical method for improving estimates, now known as "Rao-Blackwellization." An elegant and important form of the renewal theorem is due to Blackwell, as is a beautiful characterization of the information content of an experiment. In game theory, he initiated the study of duels (with Girshick) and later made several deep contributions to our understanding of sequential games and the role of information therein.