Dear all,

tomorrow we will have a LIRa session with Hein Duijf.

Everyone is cordially invited!

Speaker: Hein Duijf (Utrecht University)

Date and Time: Friday, May 27th 2016, 13:00-14:30

Venue: ILLC Seminar Room F1.15, Science Park 107

Title: Cooperative Rationality: beyond team reasoning.

Abstract. The vast majority of philosophical accounts of collective intentionality rely on members 'intentions to do their part in the collective act'. It is, however, far from clear what this means. It has been proposed that the economic literature on team reasoning (as studied by Bacharach, Sugden and Gold) can shed some light on this philosophical debate. Although it has been argued that team reasoning corrects and extends individualistic decision theory (by studying Hi-Lo games), we aim to show that it is surprisingly weak in two regards: (1) it fails to transcend individualistic decision theory, since it can be explained as a change of motive, and (2) a new challenge is presented where the team reasoning account fails and individualistic decision theory succeeds in capturing the cooperative incentives, thus providing justification that they are on a paradoxical par. Reform is required. We propose a logic of agency and intentionality to adequately reduce team reasoning to a certain intention type, coined team intention. Such a member's team intention inclines her to perform an individual action that is, merely, compatible with a best group action. On the one hand, this reduction shows that team reasoning can be adequately explained by a change of motive. Team reasoning is hence moved into the ball park of individualistic decision theory, coupled with preference transformations, which it was supposed to transcend. On the other hand, it reveals the weakness of team reasoning and points to an enhancement. To rectify the situation, we utilise the logical language to introduce participatory intentions, which incline an agent to promote that a best group action is performed. Our main result is two-fold: (1) participatory intentions correctly address the new challenge and (2) participatory intentions surpass team intentions, and therefore also team reasoning.

Hope to see you there!

The LIRa team