[This paper examines a notion of coalitional fairness for exchange allocations. An allocation is "c-fair" if no coalition of traders could benefit from achieving the net trade of some other coalition. Properties of c-fair allocations are studied both in exchange economies with a finite number of traders and with an atomless sector.]

[This paper is a natural outgrowth of recent studies in markets with a "continuum" of traders. An equivalence theorem for the core of such economies was obtained, under the assumption that the measure space of economic agents is atomless. We introduce a sufficient condition under which the preceding result can be extended to economies containing "atomic" traders. The condition bears on the measure of the atoms.]