Three methods to share joint costs or surplus

We study cost sharing methods with variable demands of heterogeneous goods, additive in the cost function and meeting the dummy axiom. We consider fou r axioms: scale invariance (SI); demand monotonicity (DM); upper bound for homogeneous goods (UBH) placing a natural cap on cost shares when goods are homogeneous; average cost pricing for homogeneous goods (ACPH). The random order values based on stand alone costs are characterized by SI and DM. Se rial costsharing, by DM and UB; the Aumann-Shapley pricing method, by SI an d ACPH. No other combination of the four axioms is compatible with additivi ty and dummy. (C) 1999 Academic Press.