Ranking animal body parts according to their economic utility has enabled archaeologists to investigate the economic decisions that resulted in the differential deposition of body parts in faunal assemblages. One of the indices developed by Lewis Binford ranks animal bone according to the quantity and quality of the marrow associated with each bone. The present study demonstrates that a much simpler index based solely on the amount of marrow is a better predictor of marrow extraction by Nunamiut and shows that additional insights into marrow use are obtained when the parts are ranked on the basis of the costs in time and the benefits in calories of extracting bone marrow. -- AATA