Max-Planck-Institut fur¨ Mathematik in den Naturwissenschaften Leipzig Risk Preferences in Time Lotteries (revised version: September 2021) by Yonatan Berman and Mark Kirstein Preprint no.: 26 2020 Risk Preferences in Time Lotteries∗ Yonatan Berman† Mark Kirstein‡ 20th August 2021 An important but understudied question in economics is how people choose when facing uncertainty in the timing of events. Here we study preferences over time lotteries, in which the payment amount is certain but the payment time is un- certain. Expected discounted utility theory (EDUT) predicts decision makers to be risk-seeking over time lotteries. We explore a normative model of growth- optimality, in which decision makers maximise the long-term growth rate of their wealth. Revisiting experimental evidence on time lotteries, we find that growth- optimality accords better with the evidence than EDUT. We outline future ex- periments to scrutinise further the plausibility of growth-optimality. Keywords Ergodicity Economics, Growth-Optimal Preferences, Time Lotteries JEL Classification C61 · D01 · D81 · D9 arXiv:2108.08366v1 [econ.TH] 18 Aug 2021 ∗ We benefited from detailed comments by Alexander Adamou and Ole Peters. We also wish to thank Alex Kacelnik for fruitful discussions, along with seminar participants at the Max Planck Institute for Mathematics in the Sciences, Leipzig, University of Duisburg-Essen, and Rutgers University, and with conference participants at the D-TEA Conference 2020 and the 2020 Annual Meeting of the German Economic Association. † B
[email protected], London Mathematical Laboratory ‡ B
[email protected], Max-Planck-Institute for Mathematics in the Sciences 1 1 Introduction Real-world economic decisions are usually a combination of at least two types of uncertainties.