Rationalizable Trade

We formulate necessary and sufficient conditions for interim rationalizable trade between two players.

Conditioning and Aggregation of Preferences

This paper contains a formulation of conditional preferences and their aggregation across states of nature and time that is consistent with, but does not imply, an expected utility representation of preferences, state-independence, or consequentialism. Under weak consistency conditions, the conditional utility of an act given certain information is related to the conditional utility of the same act given some coarser information through a (not necessarily additive) map, called an "aggregator." Sufficient conditions for additive aggregation are developed, based on standard theory of additive conjoint measurement. In an temporal setting, a "tie-coherence" axiom links conditional utilities and aggregators across time, providing the foundation for various forms of recursive utility. The general theory of conditioning and aggregation of preferences is applied to derive additive and recursive utility representations of preferences for information. The associated concept of information affinity (or aversion) is defined and related to recursive utility.

Rationalizable Trade

We formulate necessary and sufficient conditions for interim rationalizable trade between two players

Recursive utility and preferences for information

This paper presents an axiomatic foundation for recursive utility that captures the role of the timing of resolution of uncertainty without relying on exogenously specified objective beliefs. Two main representation results are proved. In the first one, future utility enters the recursion through the type of general aggregators considered in Skiadas (1997a), and as a result the formulation is purely ordinal and free of any probabilities. In the second representation these aggregators are conditional expectations relative to subjective beliefs. A new recursive representation incorporating disappointment aversion is also suggested. The main methodological innovation of the paper derives from the fact that the basic objects of choice are taken to be pairs of state-contingent consumption plans and information filtrations, rather than the temporal (objective) lotteries of the existing literature. It is shown that this approach has the additional benefit of being directly applicable to the continuous-time version of recursive utility developed by Duffie and Epstein (1992)