Fairness for Robust Learning to Rank

Omid Memarrast, Ashkan Rezaei, Rizal Fathony, Brian D. Ziebart

Abstract: While conventional ranking systems focus solely on maximizing the utility of the ranked items to users, fairness-aware ranking systems additionally try to balance the exposure based on different protected attributes such as gender or race. To achieve this type of group fairness for ranking, we derive a new ranking system from the first principles of distributional robustness. We formulate a minimax game between a player choosing a distribution over rankings to maximize utility while satisfying fairness constraints against an adversary seeking to minimize utility while matching statistics of the training data. Rather than maximizing utility and fairness for the specific training data, this approach efficiently produces robust utility and fairness for a much broader family of distributions of rankings that include the training data. We show that our approach provides better utility for highly fair rankings than existing baseline methods.