There are three reasons why the reported product margins for the two costing systems differ from one another. The first reason is that the traditional cost system allocates all manufacturing overhead to products. The ABC system only assigns manufacturing overhead costs consumed by products to those products. More specifically, the ABC system does not assign the manufacturing overhead costs consumed by the customer relations activity to products because these costs are caused by customers, not specific products. The ABC system does not assign the manufacturing overhead costs included in the “other” activity to products because these organization-sustaining and unused capacity costs are not caused by products.