Working Paper

Ambiguity Aversion is the Exception

Martin G. Kocher, Amrei M. Lahno, Stefan T. Trautmann
CESifo, Munich, 2015

CESifo Working Paper No. 5261

Assuming universal ambiguity aversion, an extensive theoretical literature studies how ambiguity can account for market anomalies from the perspective of expected utility-based theories. We provide a systematic experimental assessment of ambiguity attitudes in different likelihood ranges and in the gain domain, the loss domain and with mixed outcomes. We draw on a unified framework with more than 500 participants and find that ambiguity aversion is the exception, not the rule. We replicate the usual finding of ambiguity aversion for moderate likelihood gains. However, when introducing losses or lower likelihoods, we observe ambiguity neutrality or seeking, rejecting universal ambiguity aversion.

CESifo Category
Behavioural Economics
Empirical and Theoretical Methods
Keywords: ambiguity aversion, decision under uncertainty, Ellsberg experiments
JEL Classification: C910, D810