Prospect Theory finds that most of us feel a loss much greater than we do a gain. It’s another asymmetry: losses hurt more than gains feel good (loss aversion).
Prospect theory is a behavioral economic theory that describes the way people choose between probabilistic alternatives that involve risk, where the probabilities of outcomes are known. … The paper “Prospect Theory: An Analysis of Decision under Risk” (1979) has been called a “seminal paper in behavioral economics”.
Source: Prospect Theory Wikipedia