Joint costs are allocated to products based on some convenient allocation base rather than a cause-and-effect measure of resources used by each joint product. Therefore, these costs are not a useful basis for pricing decisions. If sales value at splitoff or the net realizable value method is used to allocate joint costs, the selling prices of joint products drive joint-cost allocations, rather than cost allocations serving as the basis for the pricing of joint products! Of course, as we saw in Chapter 14, the joint products must generate a sufficient amount of combined revenue in the long run to cover the joint costs of processing.