Security effect
As a security effect (Engl. Certainty effect ) is a cognitive bias called that people at a decision under uncertainty rate much higher then the difference between two probabilities, if this can be achieved absolute certainty. A transition from 99 to 100 percent is rated as more important than a transition from 50 to 51 percent. While this is merely a quantitative improvement, this represents a qualitative transition.
Similarly, a transition from 0 to 1 percent scores much higher than a transition from 50 to 51 percent. This is called opportunity effect (Engl. Possibility effect ), respectively. Example: In order to reduce the risk of a catastrophe (reactor accident, amputation or the like) from 5 to 0 percent (i.e. to exclude it completely), people would invest a lot more than for the reduction from 10 to 5 percent.
Both effects show that people irrationally attach great importance to improbable events. This finding is one of the improvements of the prospect theory compared to the classic expected utility theory .
source
- Daniel Kahneman (2011): Thinking, fast and slow , Allen Lane Paperback, ISBN 978-1-846-14606-0 , therein Chapter 29 "The Fourfold Pattern", pp. 310–321