Risk aversion

In economics and finance, risk aversion is the behavior of humans (especially consumers and investors), when exposed to uncertainty, to attempt to reduce that uncertainty. It is the reluctance of a person to accept a bargain with an uncertain payoff rather than another bargain with a more certain, but possibly lower, expected payoff. For example, a risk-averse investor might choose to put his or her money into a bank account with a low but guaranteed interest rate, rather than into a stock that may have high expected returns, but also involves a chance of losing value.

Example

A person is given the choice between two scenarios, one with a guaranteed payoff and one without. In the guaranteed scenario, the person receives $50. In the uncertain scenario, a coin is flipped to decide whether the person receives $100 or nothing. The expected payoff for both scenarios is $50, meaning that an individual who was insensitive to risk would not care whether they took the guaranteed payment or the gamble. However, individuals may have different risk attitudes

Risk aversion (psychology)

Risk-aversion is a preference for a sure outcome over a gamble with higher or equal expected value. Conversely, the rejection of a sure thing in favor of a gamble of lower or equal expected value is known as risk-seeking behavior.

The psychophysics of chance induce overweighting of sure things and of improbable events, relative to events of moderate probability. Underweighting of moderate and high probabilities relative to sure things contributes to risk-aversion in the realm of gains by reducing the attractiveness of positive gambles. The same effect also contributes to risk-seeking in losses by attenuating the aversiveness of negative gambles. Low probabilities, however, are overweighted, which reverses the pattern described above: low probabilities enhance the value of long-shots and amplify aversion to a small chance of a severe loss. Consequently, people are often risk-seeking in dealing with improbable gains and risk-averse in dealing with unlikely losses.