No, it’s the appropriate measure of ”unfairness.” If you designed a system where 5 black guys got misidentified but 1 white guy, out of the U.S. population, tha

No, it’s the appropriate measure of ”unfairness.” If you designed a system where 5 black guys got misidentified but 1 white guy, out of the U.S. population, that would be far less unfair compared to 2%/1% despite the ratio being higher. And why did you pick that ratio to compare instead of 90%/80% vs. 99%/98%? The right means of comparison — for fairness — is the absolute difference in proportion. I don’t mean to imply that’s the right metric at all, of course, because it specially privileges minorities. The proper measure should equally weight the algorithm’s performance on all people in the population, or at least weight them irrespective of race. That’s just not a measure of fairness between races.