Different metrics and location problems.

Many problems in operations research and in economics reduce to the finding of one or more points minimizing some function of the distance. The Euclidean distance is most commonly used: such a metric is often well suited to modeling problems, but—above all—it is simple and behaves most regularly with respect to mathematical properties. Anyhow, some problems are better modeled (at least from some points of view) by other metrics; e.g., by the rectilinear one. Therefore, it is useful to have estimates concerning the difference among solutions based on different choices of the distance function. In this note we give, hopefully, a contribution in this directio