This article investigates the effect of being assigned to different class tracks on education outcomes in higher education. We use administrative data from a Chinese university where students are assigned to two tracks of English education. Students in the high achieving track enjoy exposure to better peers, but receive less instruction time before taking a national English test. A regression discontinuity design establishes evidence that being assigned to the high achieving track has a negligible effect. Our analysis shows that the null impact is due to the offsetting effects of instruction time and peers. (JEL I21, I23)