Result
It is impossible to verify that an agent is vNM-rational by observing its actions without access to the domain of its utility function.
Motivation
Alphonso and Beatriz both go the market to buy fruit.
Alphonso prefers grapes to oranges.
He fills his basket with grapes and pays for them.
Beatriz carefully picks through the fruit and purchases some oranges and some grapes.
Callisto arrives with a package of grapes.
"Say, Beatriz, would you like to trade some of your oranges for this package of grapes?" Callisto offers.
"Gladly." Beatriz replies, exchanging some of her oranges for the grapes.
A few moments later, Alphonso notices Beatriz giving Deion some grapes in exchange for some oranges.
"You are acting irrationally, Beatriz!" Alphonso exclaims. "Your... (read 157 more words →)