Discussion paper

DP6091 Royalty Stacking in High Tech Industries: Separating Myth from Reality

A few recent contributions have claimed that in high-tech industries?where innovation is often cumulative and products include many components which are protected by patents in the hands of many different patent holders?the cost of obtaining all necessary licenses is too high. Some have even requested sweeping policy reforms to deal with the so-called royalty stacking problem. In this Essay we find that the empirical evidence?including new evidence for the 3G telecom industry?does not corroborate the gloomy predictions of the proponents of the royalty stacking hypothesis. A careful look at the theoretical underpinnings of this hypothesis explains the lack of empirical support. First, three necessary conditions must be satisfied for a royalty stacking problem to exist: (a) innovation must be cumulative, so that the patents are complementary; (b) there must be many patents for a given product; and (c) the many patents must be held by numerous, distinct rights holders. Second, royalty stacking may not be a problem even if the three necessary conditions are met; i.e., the three necessary conditions are not sufficient. And, third, several market mechanisms, such as cross licensing or voluntary patent pools, can be used to mitigate the costs of multiple concurrent patent negotiations. We conclude that the so-called royalty stacking problem is more myth than reality and that there is no reason to adopt the dramatic reforms in antitrust and patent law that have been recently proposed by, inter alia, Lemley and Shapiro (2006).


Padilla, J, A Layne-Farrar and D Geradin (2007), ‘DP6091 Royalty Stacking in High Tech Industries: Separating Myth from Reality‘, CEPR Discussion Paper No. 6091. CEPR Press, Paris & London. https://cepr.org/publications/dp6091