 #000, December 0000. "During the sample period (0000-0000) two significant mergers occurred: one between Pergamon (00 biomedical titles) and Elsevier (000) and the other between Lippincott (00) and Kluwer (00). To estimate the impact of these mergers on the prices of the biomedical journals being studied, a subset of data from the larger sample of medical libraries was analyzed. According to these empirical estimates, each of these mergers was associated with substantial price increases; in the case of the Elsevier deal the price increase was due solely to increased market power....For example, compared to premerger prices, the Elsevier deal resulted in an average price increase of 00% for former Pergamon titles, and an 0% increase for Elsevier titles. This asymmetry probably reflects the corresponding asymmetry in premerger journal portfolio size for the two firms. That is, Pergamon's relatively small biomedical portfolio prevented it from realizing it could profitably set prices at the same level as Elsevier for journals in the same class. In the Lippincott/Kluwer merger, a 00% price increase in former Lippincott titles was due in part to increased market power, but also due in part to an apparent increase in the inelasticity of demand for the titles. That is, after the merger, Lippincott titles were even less likely to be cancelled. These results also contain a likely explanation for the persistent journal price inflation observed in most academic fields.00 The sensitivity of library demand to price increases is very small by normal standards (a 0% increase in price results in a 0.0% decline in subscriptions). Given this inelastic demand, publishers have a strong incentive to increase prices faster than the growth rate of library budgets...." 