Prospekteorien

Prospekteorien, often translated as prospect theory, is a descriptive model of decision-making under risk developed by psychologists Daniel Kahneman and Amos Tversky. It emerged as an alternative to expected utility theory, which assumes individuals make rational choices to maximize their expected gains. Prospect theory highlights that people do not always behave rationally and are influenced by psychological factors when making decisions involving potential losses and gains.

The theory posits that individuals evaluate outcomes relative to a reference point, which is typically their current situation. Gains are perceived relative to this reference point, as are losses. A key finding is that people are generally risk-averse when it comes to gains, meaning they prefer a sure gain over a gamble with a higher expected value. Conversely, they tend to be risk-seeking when facing losses, preferring to take a gamble to avoid a sure loss, even if the expected value of the gamble is lower.

Another crucial aspect of prospect theory is the concept of diminishing sensitivity. The subjective impact of both gains and losses decreases as their magnitude increases. For example, the difference in satisfaction between gaining $10 and $20 is perceived as greater than the difference between gaining $1000 and $1010. Similarly, the pain of losing $10 is felt more intensely than the difference between losing $1000 and $1010.

Furthermore, prospect theory incorporates the idea of probability weighting, where individuals subjectively overweight small probabilities and underweight moderate to high probabilities. This explains phenomena like people buying lottery tickets despite the extremely low odds of winning. The theory has had a significant impact on behavioral economics, finance, and psychology, offering a more realistic account of how people make choices when uncertainty is involved.