Dalrymples writes at The Library of Law and Liberty on the sticky philosophical issues involved in racial discrimination. Analyzing the case of Washington DC taxi drivers refusing service to young black male passengers, Dalrymple shows that it is unjust for such passengers to be refused service but also unjust to force taxi drivers to bear the additional risk of picking them up (assuming the statistics that show that such passengers commit violence and skip out on fares more frequently are accurate). How do you negotiate such competing injustices? There is no easy answer.
…it is a matter of judgment at what point such discrimination becomes morally reprehensible. The avoidance of a trivial risk, either because the thing avoided is itself trivial (let us say the risk of a smaller tip) or because it is statistically negligible, would certainly render such discrimination reprehensible, for then injustices would be committed for no good reason. But the precise point at which a risk is trivial is not discernible by science and depends on the point of view of the person running it. As the eminent British physician, Sir George Pickering, once put it, a minor operation is an operation performed on someone else.