These are all very good and true points, but I think one of the questions the parent poster was trying to ask was what happens if an observed bias evident in a model's output simply proportionally lines up with reality, even when controlling for confounders.

(This is all further demonstration of just how complex a term like "correct" can be in this case, as you point out, but I think it's worth considering the whole spectrum and perhaps the "Devil's advocate" instances of potential correctness.)

This is one example recently given by the founder of a controversial AI-based insurance company (https://www.lemonade.com/blog/ai-can-vanquish-bias/), where he claims sufficiently fine-grained AI classification actually reduces group bias even if in some cases the output may, in aggregate, be statistically biased towards particular groups:

>Let’s say I am Jewish (I am), and that part of my tradition involves lighting a bunch of candles throughout the year (it does). In our home we light candles every Friday night, every holiday eve, and we’ll burn through about two hundred candles over the 8 nights of Hanukkah. It would not be surprising if I, and others like me, represented a higher risk of fire than the national average. So, if the AI charges Jews, on average, more than non-Jews for fire insurance, is that unfairly discriminatory?

>It depends.

>It would definitely be a problem if being Jewish, per se, resulted in higher premiums whether or not you’re the candle-lighting kind of Jew. Not all Jews are avid candle lighters, and an algorithm that treats all Jews like the ‘average Jew,’ would be despicable. That, though, is a Phase 2 problem.

>A Phase 3 algorithm that identifies people’s proclivity for candle lighting, and charges them more for the risk that this penchant actually represents, is entirely fair. The fact that such a fondness for candles is unevenly distributed in the population, and more highly concentrated among Jews, means that, on average, Jews will pay more. It does not mean that people are charged more for being Jewish.

>It’s hard to overstate the importance of this distinction. All cows have four legs, but not all things with four legs are cows.

>The upshot is that the mere fact that an algorithm charges Jews – or women, or black people – more on average does not render it unfairly discriminatory. Phase 3 doesn’t do averages. In common with Dr. Martin Luther King, we dream of living in a world where we are judged by the content of our character. We want to be assessed as individuals, not by reference to our racial, gender, or religious markers. If the AI is treating us all this way, as humans, then it is being fair. If I’m charged more for my candle-lighting habit, that’s as it should be, even if the behavior I’m being charged for is disproportionately common among Jews. The AI is responding to my fondness for candles (which is a real risk factor), not to my tribal affiliation (which is not).

One thing his post doesn't discuss is what might cause such a group correlation and how much agency is involved. In the case of candle-lighting, it's presumed that people (Jewish or otherwise) are doing it purely out of their own free will, or at least due to a belief/practice they largely have choice over.

If instead the root cause is hypothetically partly or wholly extrinsic (e.g. police being disproportionately more likely to arrest people among certain groups, with it remaining disproportionate after accounting for the true crime frequency/severity base rate for individuals in that group), then I think an analogue of the above example wouldn't hold up, because, as you say, the inputs would be inherently unjust, even if they're in some sense statistically predictive. So it'd be unfair to use such data.

Then there's the grayer area. What if a group is hypothetically disproportionately represented among a certain data set or proxy but the representation is commensurate with the true base rate among individuals of that group?

In some sense, it's not unfair, because you're getting actual data based on what people are actually choosing to do or not do.

But it opens the door into larger arguments of culpability, free will, being dealt a bad hand, etc. It's inherently unfair to be born into a very poor family or a crime-ridden area or a house with lead paint or as the ancestor of generations of people who were oppressed, abused, shut out of society, and otherwise treated very unfairly, let alone potentially abducted, enslaved, and/or subject to genocide. Even if the true rate hypothetically lines up with the proxy, there still might linger impactful and lasting trickle-down effects from generations of very unfair and incorrect proxies. So it could potentially be correct inputs, correct outputs, but still unfair in a deep sense. However, is it unfair to the point of it violating discrimination laws? I don't actually know. And I could see many different arguments about the ethics of such outputs.

And then there are of course the epistemological problems / meta-problems, here, which might be the trickiest of all: how do or can you know the data is accurate, how do or can you know the true base rate, etc. So it's very difficult to tell in practice how fair any particular metric is.

Bias is clearly a major issue for AI, but I think it's a pretty nuanced subject. It's easy (but of course deeply necessary) to list all the actual and theoretical failure modes, but it's hard to always truly determine how fair something is and exactly what ethical and philosophical principles to use when judging fairness.

I know that's basically just a reiteration of your point, but I always see this framed from the perspective of how easy it is to get things wrong, without examples of cases where one could potentially "steelman" the wrongness; or earnestly steelman it yet still ultimately conclude it doesn't conform to a particular society's values, even if it might conform to laws. (Or at least a subset of a society's values - given some of the seeming fundamental value divides in the US. Two people could agree about most of the above but come to very different conclusions if one of them is socially left-leaning and the other is socially right-leaning.)