ABSTRACT: Suppose we have a group of Bayesian agents, and suppose that they would like for
their group as a whole to be a Bayesian agent as well. Moreover, suppose that those agents want the
probabilities and utilities attached to this group agent to be aggregated from the individual
probabilities and utilities in reasonable ways. Two ways of aggregating their individual data are
available to them, viz., ex ante aggregation and ex post aggregation. The former aggregates expected
utilities directly, whereas the latter aggregates probabilities and utilities separately. A number of
recent formal results show that both approaches have problematic implications. This study discusses
the philosophical issues arising from those results. In this process, I hope to convince the reader that
these results about Bayesian aggregation are highly significant to decision theorists, but also of
immense interest to theorists working in areas such as ethics and political philosophy.
The results seem quite significant, even if it’s not clear what they mean. One possible interpretation is that expected utility maximization is not the correct ideal for group rationality.
The Theory of Bayesian Aggregation—Bayesian Group Agents and Two Modes of Aggregation by Mathias Risse.
ABSTRACT: Suppose we have a group of Bayesian agents, and suppose that they would like for their group as a whole to be a Bayesian agent as well. Moreover, suppose that those agents want the probabilities and utilities attached to this group agent to be aggregated from the individual probabilities and utilities in reasonable ways. Two ways of aggregating their individual data are available to them, viz., ex ante aggregation and ex post aggregation. The former aggregates expected utilities directly, whereas the latter aggregates probabilities and utilities separately. A number of recent formal results show that both approaches have problematic implications. This study discusses the philosophical issues arising from those results. In this process, I hope to convince the reader that these results about Bayesian aggregation are highly significant to decision theorists, but also of immense interest to theorists working in areas such as ethics and political philosophy.
Wasn’t as enlightening as the abstract made it sound.
The results seem quite significant, even if it’s not clear what they mean. One possible interpretation is that expected utility maximization is not the correct ideal for group rationality.
Or they just do it totally wrong.
Good find, thanks!