Abstract: The sunk cost effect is a irrational phenomena that occurs when the current decision-making is made based on sunk cost. In this paper, we reviewed scientific literature on the sunk cost effect. According to traditional economic theory, a rational decision-maker is expected to not let sunk cost, which incurred in the past and cannot be changed now and in the future, influence his or her current decision-making. However, collective evidence indicated that decision-makers are particularly vulnerable to sunk costs, thus demonstrating the sunk cost effect. Since first confirmed empirically by Arkes and Blumer in 1985, the sunk cost effect has been documented in various domains, including consumer behavior, progress management, clinical treatment, personal relationship and even war policy. Thus a better understanding of the sunk cost effect, especially its underlying mechanisms and influencing factors, is crucial to avoid this ubiquitous decision-making bias. Generally, existing literature has examined the sun cost effect in two types of decision task, utilization decisions and progress decisions, which even could be distinguished as two research paradigms. Underlying mechanisms of the sun cost effect were summarized as following: (1) cognitive frameworks including prospect theory, mental accounting and query theory; (2) motivative frameworks, such as self-justification and waste-avoidance; (3) neural mechanisms. In addition, factors that may moderate the sunk cost effect include (1) characteristics of sunk cost, e. g., the magnitudes of sunk cost and the type of sunk cost; (2) contexts of sunk cost decision, which refers to time delay between sunk cost and current decision, and how the information of sunk cost is framed; (3) individual characteristics, e. g., age, domain-specific expertise and personality; (4) cultural difference distinguishing individualism vs. collectivism. On the basis of the review of existing researches, four future directions for this line of research were also discussed. First, since sunk costs in existing researches are usually presented and manipulated under hypothetical scenarios which may limit its ecological validity, future researches therefore are expected to be conducted with real sunk cost. In addition, distinguishing two types of decision task empirically is also suggested. Second, the sunk cost effect has been repeatedly established in nonhuman animals, so it is an interesting question as to what do these findings mean for humans’ sunk cost effect. Besides, rational reasons behind the sunk cost effect may suggest future researchers to figure out to what extent decision-makers are relatively rational. Third, the sunk cost effect has been exclusively documented from monetary cost, whether and how behavioral sunk cost effect occurs deserve more attention. Fourth, although the sunk cost effect researches are numerous, few have involved coping strategies. Therefore, how to avoid the sunk cost effect for decision makers facing with various sunk cost ought to be explored. In addition to adverse effects, the sunk cost effect may be used positively, e.g., enhance consumer loyalty as switching barrier or promote target action serving as commitment device. Future researches hence need to define the pros and cons of the sunk cost effect, and when and how it could play a positive role.

Key words: sunk cost effect, escalation of commitment, prospect theory, mental accounting, self-justification

摘要： 沉没成本效应是指决策者的决策行为因受沉没成本影响而产生的一种非理性决策现象。针对这一决策偏差的产生根源，研究者从认知、动机和神经三个角度提出了解释。沉没成本效应的影响因素包括沉没成本特性、情境因素、个体差异和文化差异等。基于先前研究存在的问题和不足，沉没成本效应的未来研究应着眼于改进研究方法，探究产生根源，关注行为沉没成本和加强应用研究。

关键词: 沉没成本效应, 承诺升级, 预期理论, 心理账户, 自我申辩