Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We compare competing college admission matching mechanisms that differ in preference submission timing (pre-exam, post-exam but pre-score, or post-score) and in matching procedure (Boston (BOS) and serial dictatorship (SD) matching). Pre-exam submission asks students to submit college preferences before entrance exam scores are known, whereas post-score (post-exam) submission removes (reduces) score uncertainties. Theoretical analyses show that although mechanisms with post-score submission or SD matching are ex-post fair and efficient, they are not so ex-ante. Instead, the mechanism with pre-exam submission and BOS matching can be more fair and efficient ex-ante. These hypotheses are supported by empirical test on data from a top school at a top-ranked Chinese university with identification based on temporal and provincial changes. We find that although students admitted under the pre-exam BOS mechanism have lower college entrance exam scores than students admitted through other mechanisms on average, they exhibit similar or even better college academic performance.