For decades, skeptics of civil rights legislation have offered a perverse-effects argument. That argument starts from the well-founded premise that it is more difficult to enforce prohibitions on discrimination at the hiring stage than at the termination stage. Although disappointed applicants rarely know why they didn’t get a job, workers discharged after they have been on the job for a while typically find it easier to build a case. The worker often can point to past performance evaluations, or compare her outputs to those of her coworkers, to show that she was succeeding on the job. And the lore is that juries are inclined to give longtime employees the benefit of the doubt in discriminatory-discharge cases.