When the lottery has zero mean, comparing it with a small certain gain highlights what a risk-neutral decision-maker does.

Example — When the lottery is fair, is the certain option preferable?

Variant: in the lottery I win 100100 EUR with prob. 1/21/2 and lose 100100 EUR with prob. 1/21/2. Then VˉL=0\bar V_L = 0 EUR. If the sure alternative pays even just 11 EUR, it has a greater expected value. A risk-neutral rational agent always takes the certain option if the lottery has zero mean. (Casino bets have VˉL<0\bar V_L<0: the rational agent never plays.)

Topics: Probability
Concepts: Risk aversion · Fair game · Expected value
Methods: Fair game
Skills: Probability calculation