(Cont.) The second chapter investigates the interaction of strategic uncertainty and timing in a coordination game. Carlsson and van Damme have shown that small departures from common knowledge of the game being played can dramatically alter the equilibrium set. In the game I look at, there are two equilibria, but only the risk dominant equilibrium survives such a perturbation. I augment this model by giving agents a costly option to delay choosing a strategy (thereby observing any actions that were taken without delay). Strategic uncertainty gives agents a reason to exercise this option (under complete information, it never would be). In turn, the fact that Agent B sometimes waits and chooses an action after observing Agent A's choice, mitigates the risk that A faces when taking an action that is efficient but sensitive to coordination. As a result, the efficient equilibrium is played more often; in fact, as the cost of delay vanishes, it is always played. In Chapter 3, I explore the interaction between imperfect consumer information and the endogenous level of product differentiation in a non-spatial model of monopolistic competition with horizontally differentiated products. A principle of extreme differentiation is derived: firms will always choose to differentiate either maximally or minimally. In equilibrium, differentiation is maximal when search costs are low and minimal when search costs are high, providing a new interpretation of Hotelling's classic result.

'These two volumes constitute an impressive collection of selected path-breaking works of Professor Selten. . . . Edward Elgar Publications deserve merit for bringing out most frequently-cited and prominent articles of Professor Selten in a conveniently available package.' - K. Ravikumar, Journal of Scientific and Industrial Research In 1994, the Nobel Prize was awarded to Reinhard Selten, John Nash and John Harsanyi, for pioneering analysis in game theory. Selten was the first to refine the Nash equilibrium concept of non-cooperative games for analysing dynamic strategic interaction and to apply these concepts to analyses of oligopoly.