禀赋效应或厌恶剥夺，形容当一个人拥有某项物品或资产的时候，他对该物品或资产的价值评估要大于没有拥有这项物品或资产的时候。

这一现象常常用于行为金融学的分析中，并与损失厌恶的理论相联系。由于禀赋效应，人们在决策过程中，往往会产生偏见，导致对于规避风险的考虑远远大于对于追逐利益的考虑，因此人们在出卖物品或资产时，往往索要比其本身更高的价值。

In psychology and behavioral economics, the endowment effect (also known as divestiture aversion and related to the mere ownership effect in social psychology) is the hypothesis that people ascribe more value to things merely because they own them. This is typically illustrated in two ways. In a valuation paradigm, people will tend to pay more to retain something they own than to obtain something they do not own—even when there is no cause for attachment, or even if the item was only obtained minutes ago. In an exchange paradigm, people given a good are reluctant to trade it for another good of similar value. For example, participants first given a Swiss chocolate bar were generally unwilling to trade it for a coffee mug, whereas participants first given the coffee mug were generally unwilling to trade it for the chocolate bar.