abstract:The optimism bias (also known as unrealistic or comparative optimism) is a bias that causes a person to believe that they are less at risk of experiencing a negative event compared to others. There are four factors that cause a person to be optimistically biased: their desired end state, their cognitive mechanisms, the information they have about themselves versus others, and overall mood.
Adjustments for the optimismbias have since been factored into the budget of many UK government projects, including most recently the 2012 London Olympics.