We revisit the issue of asymmetries in the relation between the price of crude oil and refined petroleum products ill the United States. An econometric analysis of monthly data indicates that the asymmetric relation between the price of Crude oil and motor gasoline is generated by refinery utilization rates and inventory behavior. The asymmetric relation between the price of crude oil and home heating oil probably is generated by contractual arrangements between retailers and consumers. Together, these results imply that price asymmetries may be generated by efficient markets. Under these conditions, there is little justification for policy interventions to reduce or eliminate price asymmetries in motor gasoline and home heating oil markets. (c) 2004 Elsevier Ltd. All rights reserved.