Introduction One of the merits of the notion of sequential equilibrium is the emphasis on out-of- equilibrium beliefs-that is, on beliefs (about past and future play)at information sets that should not be reached if given equilibrium is played. The key insight of extensive-form analysis is that out-of-equilibrium beliefs deter

Introduction These notes essentially tie up a few loose ends in Lecture 8; in particular, I exhibit examples of inefficiencies in first- and second-price auctions. I would also like to briefly comment on Questions 1 and 2 in Problem Set 2 The first-price auction may be inefficient even with private values Both examples I am going to show are due to Eric Maskin(to the best of my knowledge) The first point I wish to make is that, even in a private-values setting, asymmetries may

Introduction This lecture, as well as the next, exemplify applications of the framework and techniques developed so far to problems of economic interest. Neither lecture attempts to cover the example applications in any generality, of course; you may however find these topics of sufficient interest to warrant further study Auction theory is generally indicated as one of the \success stories\of game theory There is no doubt that the game-theoretic analysis of auctions has informed design decisions

Introduction This lecture presents the two main contributions of \interactive epistemology\to thethe- ory of normal-form games: a characterization of Nash equilibrium beliefs, and a full (i.e behavioral) characterization of rationalizability a review of the basic definitions For your convenience, I summarize the essential definitions pertaining to models of interactive

Introduction This lecture focuses on the interpretation of solution concepts for normal-form games. You will recall that, when we introduced Nash equilibrium and Rationalizability, we mentioned numerous reasons why these solution concepts could be regarded as yielding plausible restric- tions on rational play, or perhaps providing a consistency check for our predictions about

Introduction This lecture continues our analysis of games with payoff uncertainty. The three main objec- tives are: (1) to illustrate the flexibility of the Harsanyi framework (or our version thereof); (2)to highlight the assumptions implicit in the conventional usage of the framework, and the possible departures; (3) to discuss its potential problems, as well as some solutions to the latter

The vast majority of games of interest in economics, finance, political economy etc. involve some form of payoff uncertainty. A simple but interesting example is provided by auctions: an object is offered for sale, and individuals are required to submit their bids in sealed envelopes. The object is then allocated to the highest bidder at a price which depends on every bid, according to some prespecified rule (e.g. \first-price\ or \second-price\rule). In

Introduction Nash equilibrium has undoubtedly proved to be the most influential idea in game theory. enabled fundamental breakthroughs in economics and the social sciences. Its development was a major intellectual achievement; what is perhaps more important, it Recent foundational research has emphasized the subtleties in the interpretation of Nash

Introduction This lecture continues the analysis of normal-form games. We analyze general, non-zerosum games, emphasizing the informal\equation\: Rational Behavior+ Assumptions about Beliefs=Solution Concepts Before we tackle the new material, let us review what we have learned about zerosum

Introduction The purpose of this lecture is to help you familiarize with the workings of sequential equi- librium and \sequential equilibrium lite, i.e. perfect Bayesian equilibrium. The main focus is the \reputation\ result of Kreps and Wilson(1982). You should refer to OR for details and definitions: I am following the textbook quite closely. of the game in which an incumbent faces a sequence of K (potential) entrants. It is clear that, in the subgame in which the last entrant gets a chance to play, the incumbent will