In Rawls’s initial formulation, the difference principle speciied that the distribution of income and wealth, via the basic structure, was to be to “everyone’s advantage” (“Justice as Fairness” [1958] in CP 48, 50; TJ 53). In subsequent discussion in A Theory of Justice Rawls amended this formulation. He notes that the phrase “everyone’s advantage” suggests that the expectations of the various income groups are “close-knit”; they go up and down together, and “there’s no loose-jointedness, so to speak, in the way expectations hang together” (TJ 70).

“Close-knitness,” had been assumed, Rawls says, “to simplify the statement of the difference principle.” He, of course, had in mind here his own initial formulation of the difference principle, as aimed at achieving a beneit literally for everybody as regards income and wealth. But Rawls immediately adds, it is “clearly conceivable” that some groups – (for instance) those least well off – “are not affected one way or the other by changes in the expectations of the best off although these changes [may] beneit others” while having no effect on the least well off (TJ 72).

This failure of close-knitness, in fact or in hypothesis, forces a revision on Rawls’s initial formulation of the difference principle. A very general revision would say that every group is to beneit, or at least none becomes worse off. Accordingly, Rawls’s principle of “everyone’s advantage” needs to be revised to accord with this more nuanced understanding of mutual beneit. Thus, as some people improve their situations, others should continue to improve, to become better–off, or at least none becomes worse off. “Everyone’s advantage” or mutual benefit so understood is an ongoing process.