Loss aversion is the tendency for losses to feel psychologically more painful than equivalent gains feel pleasurable. Losing $100 hurts roughly twice as much as gaining $100 feels good.

Origin

Identified by Kahneman and Tversky as the foundation of Prospect Theory, which replaced expected utility theory in behavioral economics and earned Kahneman the 2002 Nobel Prize in Economics.

The Asymmetric Value Function

Gains and losses are not evaluated on the same scale. The marginal pain of additional losses exceeds the marginal pleasure of equivalent additional gains — and the curve is steeper for losses.

Where Loss Aversion Controls Behavior

• Holding losing investments too long to avoid "realizing" a loss
• Refusing promotions that require taking on visible new responsibilities
• Insurance over-purchasing — paying more for peace of mind than actuarial value
• Negotiation — concessions feel more significant than equivalent gains
• Marketing — "Don't miss out" outperforms "Get this benefit"

Override

Reframe losses as costs of doing business, not catastrophes. Track the costs of inaction as deliberately as you track the risks of action.

Reference:

Wikipedia: Loss Aversion

https://en.wikipedia.org/wiki/Loss_aversion