We model the decision problems faced by the members of societies whose new members are determined by vote. We adopt a number of simplifying assumptions: the founders and the candidates are fixed; the society operates for a fixed number of periods and holds elections at the beginning of each period;...

We show that any correlation device with rational coefficients can be generated by a mechanism where each player sends a private message to a mediator who in turn makes a public deterministic announcement. Moreover, the mechanism suggested is immunized against individual deviations.

We deal with the concept of e-consistent equilibrium which corresponds to strategies inducing an e-equilbrium in any subgame reached along the play path. Examples and existence conditions are given.

Whoever exists belongs to a species, which did not become extinct, has a (geno-) type, which should be well adjusted, and lives in a habitat which has been sustainable for a long time. To capture the first aspect we allow for interspecies competition and analyze the conditions for species...

Define the riskiness of a gamble as the reciprocal of the absolute risk aversion (ARA) of an individual with constant ARA who is indifferent between taking and not taking that gamble. We characterize this index by axioms, chief among them a “duality” axiom which, roughly speaking, asserts...