Consider the classical double marginal ization problem of single-product successive monopolies. We show that the ratio of the cost pass-through at the final sale relative to that at the wholesale level is characterized by the curvature of inverse demand in the final market. We also apply Cowan's (2012) method, which utilizes the idea of pass-through in an analysis of third-degree price discrimination, to compare consumer surplus under vertical integration and separation. (C) 2013 Elsevier B.V. All rights reserved.