If they correctly identify discrimination, then very little. Markets already severely punish employers who pay more for workers than necessary. In other words, discrimination laws act as a price control, requiring equal wages in two labor markets where the market clears at different wage levels. For statistical discrimination, discrimination laws have the same negative effects. Groups are really different on average, but the law says employers must treat them the same.
Firms then do their best to avoid paying people more than they're worth.
This would probably be illegal under current law. Under the discrimination laws, aggrieved individuals can sue employers for discriminating against them. B. Employers can defend themselves by showing that the worker was judged on the basis of individual performance. C. Still, the defense always labors under the equivocation between difference and discrimination. D. Interestingly, most discrimination suits come from workers who say their current employer mistreated them, not from workers who say they were not hired in the first place.