Pareto optimum/principle of efficiency/Rawls: simply corresponds to the Pareto optimum (see V. Pareto, Manuel d' économie politique, Paris, 1909, ch. VI, §53 and Appendix, §89.)
The point is that a configuration is always efficient when it is impossible to change it without putting people (at least one person) at a disadvantage. An efficient configuration does not imply an absolute equal distribution.
Within a range of optimal shapes, no shape is superior to the actual unequal distribution of another shape. The different characteristics are not comparable in this sense.
The principle of efficiency can be applied to the basic structure (of a community) if it is applied to the [assumed] expectations of representative members. (See J. M. Buchananan "The Relevance of Pareto Optimality", Journal of Conflict Resolution, vol. 6,1962 - J. M. Buchanan and Gordon Tullock, The Calculus of Consent, Ann Arbor, 1962.)._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
A Theory of Justice: Original Edition Oxford 2005