This section describes my on-going research, with links to unpublished Working Papers.
Probabilistic choice
This research examines axiomatic foundations for various probabilistic choice models.
I'm working with Jose Rodrigues-Neto and James Taylor on variants of the Luce model. We are currently working on a paper that examines connections between the modern literature on Luce models and an older literature on conditional probability spaces in game theory. A working paper version will be available soon...
I am also interested in random utility models. The following working paper generalises the random categorization rule (RCR) of Aguiar (Economics Letters, 2017) to allow (restricted) category-dependence of preferences:
RYAN (2024) "Category-Dependent Preferences and Stochastic Choice"
This paper also contains a new proof of the result that the Manzini and Mariotti (2014) model is the "intersection" of the RCR and the logit attention model of Brady and Rehbeck (2016).
Ambiguity and the "Jury Paradox"
This work was supported by the Royal Society of New Zealand through the Marsden Fund (16-UOA-190). The Principal Investigators are my co-authors, Simona Fabrizi and Steffen Lippert at the University of Auckland.
The Jury Paradox refers to the possibility that raising the voting threshold for conviction (e.g., from simple majority to unanimity) may increase the likelihood of convicting an innocent defendant. This perverse effect of strategic voting was pointed out by Timothy Feddersen and Wolfgang Pesendorfer (American Political Science Review, 1998). The purpose of the project is to investigate, both theoretically and experimentally, the impact of ambiguous juror beliefs on the prevalence of this paradoxical phenomenon.
In addition to the 2021 and 2022 papers in Theory and Decision, the following working paper is also part of this project:
Fabrizi, Lippert, Pan and RYAN (2024) "Unanimity under Ambiguity"
We are currently preparing additional manuscripts which analyse our experimental data.
Here are the slides from a couple of presentations on the background literature to this topic: Lecture 1 and Lecture 2
And here are slides from a (now somewhat dated) presentation that gives an overview of our research programme.