公益营销是一种将公益和营销相结合的企业营销策略，具有公益和盈利的双重属性。本研究考虑企业公益营销包含双重动机（经济动机和公益动机）和政府对企业实施补贴政策，构建竞争背景下企业公益营销基础模型，并将其延伸至供应链背景，探讨企业竞争、政府补贴政策和公益动机对企业、消费者以及社会福利的影响。研究表明：（1）企业间竞争加剧会提升企业经济收益和社会福利，增加企业对社会公益事业的投入，促使企业愿意在公益营销活动中承担更多的社会责任。（2）政府补贴政策有助于改善社会福利，激励企业提升对社会公益事业的投入，但企业可能是为了获取政府补贴，而非完全是源于其承担的社会责任。（3）在供应链背景下，尽管产品价格下降，但消费者剩余仍降低。（4）企业在公益营销活动中保留一定的公益动机，可以实现经济效益与社会效益的双赢。

Cause-related marketing (CRM) typically refers to the marketing strategy of firms that combines public welfare and marketing, with the dual motives of philanthropy and profitability. This paper constructs a stylized model that two competitive firms implement CRM strategy, and then extends this model to the supply chain context. Additionally, we examine the impacts of firm competition, government subsidy policy, and philanthropic motives on the firms, consumers, and social welfare. Our main results follow. (1) The intensified competition between firms enhances the firms' economic benefits and public welfare, increases the investment of firms in social welfare, and prompts the firms to be willing to take more social responsibility in CRM campaigns. (2) The government subsidy policy can improve social welfare and the firms' investment in public welfare; however, the firms may be aiming at getting government subsidies rather than stemming from the social responsibility they assume. (3) In a supply chain scenario, the consumer surplus is lower despite lower product prices. (4) The firms can achieve a win-win situation of economic and social benefits if they properly retain public welfare motives in CRM campaigns.