Aggregating rankings with positional constraints

We consider the problem of rank aggregation, where the goal is to assemble ordered lists into one consensus order. Our contributions consist of proposing a new family of distance measures that allow for incorporating practical ranking constraints into the aggregation problem formulation; showing how such distance measures arise from a generalization of Kemeny´s axioms of the Kendall τ distance; and proving that special classes of the proposed distances may be computed in polynomial time.