German economist extraordinaire Reinhard Selten has died. Born October 1930, he was 85.

In 1994 he was awarded the Nobel Memorial Prize in Economic Sciences which he shared with John Harsanyi and John Nash, three quarters of the NASH quartet of Nash, Aumann, Selten, Harsanyi that has been widely credited to have advanced decisively the theory of games in the fifties, sixties, seventies, and eighties. Aumann received his Nobel Prize, together with Thomas Schelling, in 2005.

Selten was awarded the Nobel Prize mainly on the strength of his game-theoretic contributions. Specifically, he was credited by the Nobel Prize Committee with the introduction of the concept of subgame perfection which defined conditions under which to exclude from a set of equilibria those which are unreasonable by some standard (non-credible threats). A decade later he provided as a further tool in the game theorist’s toolbox the concept of a trembling hand equilibrium which likewise helped to reduce the set of equilibria.

The Nobel Memorial Prize Committee in Economic Sciences credited Selten in addition explicitly with “powerful new insights regarding evolutionary games and experimental game theory”. Indeed, after he had finished his master’s thesis in 1957, Selten was hired by professor Heinz Sauermann who held a chair at the University of Frankfurt and for whom he worked in various roles as assistant for about a decade. Selten was given considerable leeway by Sauermann and, influenced by characteristic function experiments done by Kalisch et al. (1954) as well as Simon’s Models of Man (1957), embarked on the study of oligopoly experiments which ended a couple of years later in his first experimental paper (Sauermann & Selten 1959). It was through Simon’s influence as well as his own experimental work that Selten started thinking about the bounded rationality that defines much of the decision making of individuals and firms. In fact, from the very beginning of his academic career it has been this methodological dualism that has defined his work (and occasionally confounded his colleagues).

Selten – while being famously dismissive of some of the rites of the scientific community – has worked on too many topics to even start an enumeration here: “I do not want to convey the false impression that my research is single-mindedly organized around a grand question. I am easily attracted by the opportunity to shift my interests into unforeseen exciting new directions. The little coherence there is in my work is due to a desire to understand both fully and boundedly rational economic behaviour, especially in the context of game situations.” (Selten 1993, p. 113)

Selten (1993) remains a good primer of his research interests over the first three or so decades; it is also an enjoyable read. Ortmann (1999) is a succinct introduction to a set of articles selected in collaboration with Selten. Selten (1999) has a brief but very informative biographical sketch by himself. Easily accessible information about both his life and his work may be found on the website of the Nobel Prize Committee .

Acknowledgment: The above draws on a contribution I wrote for Real World Decision Making: An Encyclopedia of Behavioral Economics. (editor: Morris Altman, Praeger 2015)

References.

Kalisch, G., Milnor, J.W., Nash, J., and Nering, J.D..1954. “Some experimental n-person games.” Pp. 301-27 R.M. Thrall, C.H. Coombs, and R.L. Davis (eds). Decision processes. New York and London.

Ortmann, Andreas. 1999. “Introduction (to Selten 1999).” Pp. xi – xxi in Selten (1999)

Sauermann, Heinz, and Selten, Reinhard. 1959. “Ein Oligopolexperiment.” Zeitschrift fuer die gesamte Staatswissenschaft 115, 437-71.

Selten, Reinhard. 1993. “In Search of a Better Understanding of Economic Behaviour.” Pp. 115-39 Arnold Heertje (ed). The Makers of Modern Economics, Vol. 1. Harvester Wheatsheaf.

Selten, Reinhard. 1999. Game Theory and Economic Behaviour. Selected Essays Volumes One, Two. Cheltenham, UK and Northhampton, MA, USA: Edward Elgar.

Simon, Herbert A. 1978. “Rationality as a Process and as a Product of Thought.” American Economic Review 70: 1–16.