An Anonymized Urn-Based Experimental Dataset on Decision-Making under Risk and Ambiguity
How people bet differently when odds are clear versus murky
Researchers collected 4,486 decisions from 246 people choosing how much to wager on colored balls drawn from urns—sometimes with known odds, sometimes with unknown odds. The dataset reveals how people's willingness to pay shifts when uncertainty becomes ambiguous rather than simply risky, with online participants also rating how uncertain they felt about each choice.
Understanding how people behave under ambiguous uncertainty matters for everything from financial regulation to insurance pricing to public health policy, where real decisions often involve incomplete information. This dataset is large and detailed enough that researchers can now test competing theories about ambiguity-aversion side by side, and replicate findings that might otherwise stay trapped in individual labs.