League tables associated with various forms of service activities from schools to hospitals illustrate the public need for ranking institutions by their productive performance. We present a new method for ranking production units which is based on each units marginal contribution to the technical efficiency of various “mergers” relative to a common reference technology. The approach is radically different from the usual one based on super-efficiency indexes in DEA. We illustrate the mechanics of our method by a series of numerical examples and further demonstrate that our new index inherits all relevant and desirable properties of the Farrell efficiency index upon which it is constructed.