The Influence of Social Proof on Young Consumers' Purchase Behavior on the Shopee E - Commerce Platform

This study examines the influence of social proof on young consumers’ purchase behavior on the Shopee e - commerce platform and investigates the mediating role of fear of missing out (FOMO). Data were collected through an online survey of 674 Shopee users un der the age of 30 living, studying, or working in Hanoi and analyzed using partial least squares structural equation modelling (PLS - SEM). The results show that social proof has a positive and significant direct effect on purchase behavior and a strong posi tive effect on FOMO. FOMO also significantly increases purchase behavior. Moreover, the indirect effect of social proof on purchase behavior through FOMO is significant, indicating complementary partial mediation. The total effect of social proof on purcha se behavior reaches (  = 0.706), while the model explains 46.7% of the variance in FOMO and 61.2% of the variance in purchase behavior. These findings demonstrate that social proof influences young consumers through both informational and emotional pathways. The study contribute s to social influence, eWOM, and FOMO research in the Vietnamese e - commerce context and offers implications for platforms, online sellers, consumers, and policymakers.