The effect of social media information on college major choices in China: a difference-in-differences analysis.

The choice of a college major in China is a high-stakes decision often plagued by information asymmetry. This study provides a large-scale causal analysis of how social media influencers impact these choices. Leveraging the "Zhang Xuefeng Phenomeno", an event where a prominent influencer vehemently discouraged Journalism and Communication majors, as a natural experiment, we employ a difference-in-differences (DID) design on a comprehensive dataset of university admission ranks from 2017 to 2023, covering over 3.3 million observations. Our findings reveal that the influencer's negative signal caused the admission rank for Journalism and Communication to worsen by a substantial 13.1% across all institutions and by 24.7% at elite Double First-Class Initiative universities. A significant asymmetric response is identified, as the negative impact is nearly twice the magnitude of the positive effect observed for the endorsed Computer Science major, suggesting that student decisions are driven more by loss aversion than by the pursuit of opportunity. The robustness of these estimates is confirmed using event-study approaches and placebo tests in untargeted fields such as Philosophy and History. Furthermore, an exploratory analysis offers suggestive evidence of positive spillover effects on related practical fields, such as Transportation. A triple-difference (DDD) analysis reveals this impact is significantly weaker in provinces with higher per capita GDP. This research provides robust evidence that social media influencers have become powerful new players in the educational landscape, capable of significantly influencing students' intentions to choose a major. It also highlights novel challenges for policymakers in mitigating information asymmetry and optimizing human capital allocation to support the development of new quality productive forces.