中文摘要：

“劣势者效应”即人们给予竞争中处于劣势的一方更多支持的效应。本文主要基于文献回顾，着眼于营销应用，分析了劣势者效应概念，介绍了消费者基于劣势者信息对劣势者的识别和劣势者效应的影响因素和应用条件。过往研究表明，消费者会依据企业或品牌的竞争态势、先天资源、努力程度等因素形成劣势者判断，并给予劣势者支持；影响劣势者效应的中介因素包括身份认同动机、公平动机和功利性动机，竞争结果重要性和文化差异是劣势者效应的调节因素。最后，文章对未来研究方向进行了展望。

英文摘要：

Underdog effect refers to the phenomenon that people support those who suffer the disadvantage in a competition. Based on a literature review and marketing application, this paper analyzes the concept of underdog effect and introduces the recognition of underdogs by consumers based on underdog information and the influencing factors and application conditions of underdog effect. Previous research shows that consumers identify an underdog according to factors such as competition situation, innate resources and effort degree of enterprises or brands, and then support the underdog. Intermediary factors influencing this underdog effect include motives for identification, justice and utilitarian. Furthermore, the significance of competition consequences and cultural differences are the moderators of underdog effect. Finally, this paper points out the directions in future research.