Partition-dependent framing effects in lab and field prediction markets

Many psychology experiments show that individually judged probabilities of the same event can vary depending on the partition of the state space (a framing effect called "partition-dependence"). We show that these biases transfer to competitive prediction markets in which multiple informed traders are provided economic incentives to bet on their beliefs about events. We report results of a short controlled lab study, a longer field experiment (betting on the NBA playoffs and the FIFA World Cup), and naturally-occurring trading in macro-economic derivatives. The combined evidence suggests that partition-dependence can exist and persist in lab and field prediction markets

Graph-Based Decoding Model for Functional Alignment of Unaligned fMRI Data

Aggregating multi-subject functional magnetic resonance imaging (fMRI) data is indispensable for generating valid and general inferences from patterns distributed across human brains. The disparities in anatomical structures and functional topographies of human brains warrant aligning fMRI data across subjects. However, the existing functional alignment methods cannot handle well various kinds of fMRI datasets today, especially when they are not temporally-aligned, i.e., some of the subjects probably lack the responses to some stimuli, or different subjects might follow different sequences of stimuli. In this paper, a cross-subject graph that depicts the (dis)similarities between samples across subjects is used as a priori for developing a more flexible framework that suits an assortment of fMRI datasets. However, the high dimension of fMRI data and the use of multiple subjects makes the crude framework time-consuming or unpractical. To address this issue, we further regularize the framework, so that a novel feasible kernel-based optimization, which permits nonlinear feature extraction, could be theoretically developed. Specifically, a low-dimension assumption is imposed on each new feature space to avoid overfitting caused by the highspatial-low-temporal resolution of fMRI data. Experimental results on five datasets suggest that the proposed method is not only superior to several state-of-the-art methods on temporally-aligned fMRI data, but also suitable for dealing `with temporally-unaligned fMRI data.Comment: 17 pages, 10 figures, Proceedings of the Association for the Advancement of Artificial Intelligence (AAAI-20

Thinking in Chinese vs. Thinking in English: Social Preference and Risk Attitudes of Multicultural Minds

This paper investigates whether language priming activates different cultural identities and norms associated with the language communicated with respect to social preference and risk attitudes. Our contribution is on identifying the conditions where there will be language priming effects. We conduct economic games with bilingual subjects using Chinese and English as instructions. It is found that language priming affects social preference, but only in context involving strategic interactions. In social preference games involving strategic interactions, e.g., the trust game, subjects in the Chinese treatment are more trusting and trustworthy. In individual choice games, such as the dictator game, there is no treatment difference. Further, we also find that language priming affects risk attitudes. Subjects in the Chinese treatment prefer to pick Chinese lucky numbers in Mark Six lottery. These findings suggest that the effect of language priming is context dependent.language, bilingual, biculture, social preference, risk attitudes

Tempus Fugit: Time Pressure in Risky Decisions

We study the effects of time pressure on risky decisions for pure gain prospects, pure loss prospects, and mixed prospects involving both gains and losses. In an experiment we find that risk aversion for gains is robust under time pressure whereas risk seeking for losses turns into risk aversion under time pressure. For mixed prospects, subjects become more loss averse and more gain seeking under time pressure, depending on the framing of the prospects. The results suggest the importance of aspiration levels under time pressure. We discuss the implications of our findings for decision making situations that involve time pressure