Abstract: This article replaces action/inaction with change of state/status quo due to its shortcomings. Unitary event is distinguished from divided event in the framework of change of state-status quo. It was approved that action/inaction is only applied to unitary events but not to divided events. This conceptual framework of change of state effect adds to the power of norm theory (Kahnman and Miller, 1986) and incorporate their reception effect and action effect into one change of state effect. On the other hand, this framework also partly explains the long-lasting differences between scenario experiment and field research on regret and counterfactual thinking

Key words: change of state/status quo, action/inaction, unitary event/divided event, counterfactual thinking