To clarify, I was asking on a technical, not ethical level, about the metrics you use to optimize recommender algorithms. Meaning -- well, my frame of reference is Genetic Algorithms where you have a fitness function that evaluates potential candidate solutions. A higher score in the fitness function means a better solution.
When optimizing for engagement the fitness function is (superficially, naively) simple. Just, how much time did the user ultimately spend on the platform. My question is, if you are optimizing for 'good for humanity', what do you measure that you can wire into this function?
I have an interest in understanding this and am looking at: https://www.coursera.org/specializations/recommender-systems -- if anyone has a better suggestion, feel free!