Imagine that speeders who drive yellow cars are ticketed but speeders who drive other colored cars are not. Whether or not the traffic law explicitly singles out speeders in yellow cars, a system that reaches that result in practice would be unfair. In a death penalty system in which approximately 2% of known murderers are sentenced to death1, fairness mandates that those few who are sentenced to death should be comparable to others who are sentenced to death – and worse than those who are not.
