Law Serials Pricing and Mergers: A Portfolio Approach

Using data from more than 400 legal serials, I estimate the impact of six publisher mergers on law serial prices during the period, 1990-2000. The results suggest that merger-related price increases were substantial during this period, even after accounting for secular price trends. Furthermore, these merger effects occurred across a broadly-defined portfolio of serial titles consisting of legal encyclopedias and treatises. For other types of serials, such as newsletters and looseleaf services, these effects were not observed. Based on the portfolio demand behavior of buyers, I offer an explanation for this result based on the degree of product differentiation at the level of the individual title. Of particular interest is the purchase of West Publishing Company by Thomson Financial & Professional Publishing Group in 1996. Despite a government-mandated divestiture of more than 50 titles, the results indicate that titles published by West-Thomson experienced a significant post-merger price increase.