I'm struggling to figure out what they're trying to say here in the linked (and very anemic) paper:

> 30% of Black applicants apply to at least one position that demonstrates adverse impact against Black applicants.

The whole thing reads like a tautology.

You are reading a paper without understanding the language of the paper. Adverse Impact has a specific meaning, and in this case it's specifically meaning that Black candidates were selected only four fifths as often as white candidates when their qualifications were identical. The study is only suggesting that further investigation is warranted.