scholarly journals Fitness-Maximizers Employ Pessimistic Probability Weighting for Decisions Under Risk

2020 ◽  
pp. 1-32
Author(s):  
Michael Holton Price ◽  
James Holland Jones
Decision ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Doron Cohen ◽  
Ori Plonsky ◽  
Ido Erev

Author(s):  
Stephen G Dimmock ◽  
Roy Kouwenberg ◽  
Olivia S Mitchell ◽  
Kim Peijnenburg

Abstract We test whether probability weighting affects household portfolio choice in a representative survey. On average, people display inverse-S-shaped probability weighting, overweighting low probability events. As theory predicts, probability weighting is positively associated with portfolio underdiversification and significant Sharpe ratio losses. Analyzing respondents’ individual stock holdings, we find higher probability weighting is associated with owning lottery-type stocks and positively skewed equity portfolios. People with higher probability weighting are less likely to own mutual funds and more likely to either avoid equities or hold individual stocks. We are the first to empirically link individuals’ elicited probability weighting and real-world decisions under risk.


2018 ◽  
Author(s):  
Andreas Pedroni ◽  
Jörg Rieskamp ◽  
Thorsten Pachur ◽  
Renato Frey ◽  
Jonathan E. Westfall ◽  
...  

The investigation of decisions under risk has mainly followed one of two approaches.One relies on observing choices between lotteries in which economic primitives (outcome magnitudes, probabilities, and domains (i.e., gains and losses)) are varied systematically, and this information is described to participants. The systematic variation of the economic primitives allows to formally describe behavior with expectation-based models such as expected utility theory or cumulative prospect theory (CPT), arguably the most prominent descriptive theories of risky choice. One drawback, however, is that lottery tasks can seem artificial, likely reducing the external or ecological validity. A second more naturalistic approach employs dynamic paradigms that mimic features of real-life risky situations and are assumed to have higher ecological validity. Because key information are often not provided to the decision maker, it is impossible to apply the same models as in the first approach. The goal of the present work is to integrate both approaches, by developing models for the "hot" Columbia Card Task (CCT), a task that combines a dynamic decision situation with systematic trial-to-trial variation in economic primitives. In a model comparison on the basis of the data of 191 participants, we identified a best-performing model that describes behavior as a function of CPT’s main components, outcome sensitivity, probability weighting, and loss aversion. Our work therefore provides a framework that allows the description of risk-taking behavior in a naturalistic dynamic task based on key psychological constructs (e.g., loss aversion, probability weighting) that are rooted in the factorial variation of economic primitives.


2020 ◽  
Vol 23 (4) ◽  
pp. 1100-1128
Author(s):  
Ilke Aydogan ◽  
Yu Gao

Abstract A recent strand of the literature on decision-making under uncertainty has pointed to an intriguing behavioral gap between decisions made from description and decisions made from experience. This study reinvestigates this description-experience gap to understand the impact that sampling experience has on decisions under risk. Our study adopts a complete sampling paradigm to address the lack of control over experienced probabilities by requiring complete sampling without replacement. We also address the roles of utilities and ambiguity, which are central in most current decision models in economics. Thus, our experiment identifies the deviations from expected utility due to over- (or under-) weighting of probabilities. Our results confirm the existence of the behavioral gap, but they provide no evidence for the underweighting of small probabilities within the complete sampling treatment. We find that sampling experience attenuates rather than reverses the inverse S-shaped probability weighting under risk.


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