In order to analyze a unicellular-multicellular evolutionary transition, a multicellular organism is identified with the vector of viabilities and fecundities of its constituent cells. The Michod–Viossat–Solari–Hurand–Nedelcu index of group fitness for a multicellular organism is a...

Extensive social choice theory is used to study the problem of measuring group fitness in a two-level biological hierarchy. Both fixed and variable group size are considered. Axioms are identified that imply that the group measure satisfies a form of consequentialism in which group fitness only...

Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function....

The rationalizability of a choice function by means of a transitive relation has been analyzed thoroughly in the literature. However, not much seems to be known when transitivity is weakened to quasi-transitivity or acyclicity. We describe the logical relationship between the different notions...

In this paper we will describe a class of three-person games and draw general conclusions about non-cooperative behavior in them.

We provide a characterization of selection correspondences in two-person exchange economies that can be core rationalized in the sens that there exists a preference profil with some standard properties that generates the observed choices as the set core elements of the economy for any given...

The notion of diversity is an issue that is of relevance in several contexts. This paper provides an axiomatic approach to the measurement of diversity. We characterize two nested classes of ordinal measures of diversity and an important member of these classes.

We provide a survey of the literature on ranking sets of objects. The interpretations of those set ranking include those employed in the theory of choice under complete uncertianty, rankings of opportunity sets, set rankings that appear in matching theory, and the structure of assemly proferences.

A contingent contract in a transferable utility game under uncertainty specifies an outcome for each possible state. It is assumed that coalitions evaluate these contracts by considering the minimal possible excesses. A main question of the paper concerns the existence and characterization of...

This paper prouves a new representation theorem for domains with both discrete and continuous variables.