An Axiomatic Characterization of Some Locations In Trees

We describe axioms that uniquely characterize the absolute median and the squared median (the point that minimizes the sum of squared distances) of a tree. A common feature of these characterizations is a Consistency axiom of the type first used by H.P. Young to characterize a voting procedure called Borda's rule. These results make it possible to argue in favor of, or against, a particular location in terms of principles satisfied or violated.