Sequential contributions rules for minimum cost spanning tree problems

We introduce a family of sequential contributions rules for minimum cost spanning tree problems. Each member of the family assigns an agent some part of his immediate connection cost and all of his followers are equally responsible for the remaining part. We characterize the family by imposing the axioms of efficiency, non-negativity, independence of following costs, group independence, and weak first-link consistency. The Bird and the sequential equal contributions rules are two distinguished members of the sequential contributions rules. The Bird rule is obtained by requiring an agent to pay the whole part of the immediate connection cost, and the sequential equal contributions rule is obtained by requiring an agent and each of his followers to be equally responsible for the immediate connection cost. We show that how these two rules can be singled out from the family by imposing additional axioms. JEL Classification: C71; D70.