Abstract: Omission bias described people`s tendency to favor the loss caused by omission rather than the same or less loss caused by commission. This phenomenon is universal in people`s daily decision-making behavior, especially in social public policy area. This paper introduces two psychological mechanism of the omission bias, namely, loss aversion and norm theory. Afterwards, we introduce influential factors of the omission bias, including protected value, the knowledge of outcomes, negative emotion, social roles and cultural values. Moreover, the deficiencies existing in current research are discussed and the directions for future research on omission bias are suggested.

Key words: omission bias, loss aversion, decision avoidance, protected value