Under sequential contracting, the principal agent P negotiates with each transportation agent in sequence. That is, first P meets with t^sub 1^, then P meets with t^sub 2^, and so on. At each meeting, the two agents first consider route A to D, then route A to E, then route B to D, then route B to E. For the purposes of creating a benchmark, assume that each meeting results in a contract that, based on the information available at that moment, reflects the greatest possible benefits from exchange. (Specifically, the principal does not consider what future contracts may be possible with the other agents, who have not yet been met.) Prices for transportation services need only satisfy voluntary participation, implying that a broad range of contract prices is possible; the principal could pay as little as the transportation provider's marginal cost or as much as his entire cost savings. While there is a range of possible total costs of moving the units under this benchmark, the number of units to be moved is rigidly defined.