Why Not Rectify Past Injustices?

I just got back from a month in the UK, working for the John Locke Institute‘s two summer schools.  The morning before I left, I delivered my talk on “The Economics of Antipathy and Stereotyping.” In the subsequent Q&A, one of the students asked (roughly), “But shouldn’t we try to rectify past injustices that caused present-day differences in worker productivity?”  Since I wasn’t satisfied with my answer at the time, here are the three key points I wish I’d made.  Hopefully my John Locke student...