An Experiment on Forward versus Backward Induction: How Fairness and Levels of Reasoning Matter

We report the experimental results on a game with an outside option where forward induction contradicts with backward induction based on a focal, risk dominant equilibrium. The latter procedure yields the equilibrium selected by Harsanyi and Selten’s (1988) theory, which is hence here in contradiction with strategic stability (Kohlberg-Mertens (1985)). We find the Harsanyi-Selten solution to be in much better agreement with our data. Since fairness and bounded rationality seem to matter we discuss whether recent behavioral theories, in particular fairness theories and learning, might explain our findings. The fairness theories by Fehr and Schmidt (1999), Bolton and Ockenfels (2000) or Charness and Rabin (2002), when calibrated using experimental data on dictator- and ultimatum games, indeed predict that forward induction should play no role for our experiment and that the outside option should be chosen by all sufficiently selfish players. However, there is a multiplicity of “fairness equilibria”, some of which seem to be rejected because they require too many levels of reasoning. We show that learning theories based on naive priors could alternatively explain our results, but not that of closely related experiments

Influence of aggregation and measurement scale on ranking a compromise alternative in AHP

Author's pre-print version dated 20. December 2009 deposited in Munich Personal RePEc Archive. Final version published by Palgrave Macmillan; available online at http:// www.palgrave-journals.com/Analytic Hierarchy Process (AHP) is one of the most popular multi-attribute decision aid methods. However, within AHP, there are several competing preference measurement scales and aggregation techniques. In this paper, we compare these possibilities using a decision problem with an inherent trade-off between two criteria. A decision-maker has to choose among three alternatives: two extremes and one compromise. Six different measurement scales described previously in the literature and the new proposed logarithmic scale are considered for applying the additive and the multiplicative aggregation techniques. The results are compared with the standard consumer choice theory. We find that with the geometric and power scales a compromise is never selected when aggregation is additive and rarely when aggregation is multiplicative, while the logarithmic scale used with the multiplicative aggregation most often selects the compromise that is desirable by consumer choice theory

In and Out of Equilibrium II: Evolution in Repeated Games with Discounting and Complexity Costs

We explore evolutionary dynamics for repeated games with small, but positive complexity costs. To understand the dynamics, we extend a folk theorem result by Cooper (1996) to continuation probabilities, or discount rates, smaller than 1. While this result delineates which payoffs can be supported by neutrally stable strategies, the only strategy that is evolutionarily stable, and has a uniform invasion barrier, is All D. However, with sufficiently small complexity costs, indirect invasions - but now through 'almost neutral' mutants - become an important ingredient of the dynamics. These indirect invasions include stepping stone paths out of full defection

Evolutionary dynamics of Lewis signaling games: signaling systems vs. partial pooling

Transfer of information between senders and receivers, of one kind or another, is essential to all life. David Lewis introduced a game theoretic model of the simplest case, where one sender and one receiver have pure common interest. How hard or easy is it for evolution to achieve information transfer in Lewis signaling?. The answers involve surprising subtleties. We discuss some if these in terms of evolutionary dynamics in both finite and infinite populations, with and without mutation

Bargaining power and the impact of lender liability for environmental damages

Should lenders be made liable for environmental damages caused by their customers? In a recent paper Pitchford studied the case where the customer is a wealth-constrained manager-owned firm. He argued convincingly that a joint liability of lender and firm may reduce the firm's incentive to prevent an environmental damage and may therefore be socially harmful. However, his argument hinges on the assumption that the lender has no bargaining power and makes 0-profits in a contract. In this paper we study all possible optimal contracts between the borrower and the lender. In particular we study the case where the lender has all the bargaining power. We use the weighted Nash-bargaining solution to handle both cases in a unified framework. The results for the case where the lender has a high bargaining power differ substantially from Pitchford's findings. Then a joint liability rule is socially preferable to single liability of the firm. In fact, often it is optimal to require a liability above the actual costs of a damage or to set it so high that it extracts all potential profits from the projec

On the interpretation of evolutionarily stable sets

We introduce notions of evolutionary stability for sets of strategies based on the following requirements: After every sufficiently small mutation of a population playing a single strategy in the set: a) No single mutant strategy can spread. b) A single mutant strategy not in the set will be driven out. Depending on the precise interpretation of "a sufficiently small mutation" in these requirements we distinguish "simple ES sets", "pointwise uniform ES sets" and "uniform ES set". In contrast to the original definition of an ES set by Thomas (1985d) our definitions do not require the sets to be closedWe show: 1) A uniform ES set is always an ES set as defined by Thomas. 2) For analytic fitness functions, and hence for all symmetric normal form games, the notions of pointwise uniform ES set and ES set coincide. 3) All four definitions of evolutionary stability for sets coincide in symmetric bimatrix games

Universality of Nash components

We show that Nash equilibrium components are universal for the collection of connected polyhedral sets. More precisely for every polyhedral set we construct a so-called binary game-a game where all players have two pure strategies and a common utility function with values either zero or one-whose success set (the set of strategy profiles where the maximal payoff of one is indeed achieved) is homeomorphic to the given polyhedral set. Since compact semi-algebraic sets can be triangulated, a similar result follows for the collection of connected compact semi-algebraic sets. We discuss implications of our results for the strategic stability of success sets, and use the results to construct a Nash component with index k for any fixed integer k