First, that requires defining merit. Only New York City defines it as the score on a single test — other cities’ selective high schools use multiple measures, as do top colleges. There are certainly other potential criteria, such as artistic achievement or citizenship.

However, when merit is defined as achievement in school, the question of whether the test is meritocratic is an empirical question that can be answered with data.

https://www.chalkbeat.org/posts/ny/2018/06/22/ive-spent-years-studying-the-link-between-shsat-scores-and-student-success-the-test-doesnt-tell-you-as-much-as-you-might-think/