ABC traces expenses into cost with resource and activity drivers and provides much cost visibility that is traditionally hidden. Sadly, many organizations continue to use a single indirect and shared expense “pool”that allocates resource expenses into costs based on a single cost factor, which violates cost accounting's causality principle. Hence, compared to ABC’s disaggregating a single cost pool into multiple ones and tracing each pool with an activity cost driver based on a causeand-effect relationship, the existing costs are flawed and misleading. The products and service lines are simultaneously over- and under-costing because allocations always have a zero sum error. It’s baffling how accountants can accept this deficient practice when ABC is a better alternative