Claiming more: the increased voluminosity of patent applications and its determinants

The size of patent applications has doubled over the past two decades, resulting in a dramatic surge in the workload of patent offices all over the world and serious concerns over patent quality standards. The current paper investigates the sources of this inflation in claims and pages for EPO applications. Four hypotheses are quantitatively examined: the diffusion of national drafting practices, the complexity of research activities, the emergence of new sectors, and filing strategies. The results validate the four hypotheses. They reveal major differences across countries in patent drafting styles, especially between Civil and Common Law countries, the latter being characterized by much larger patents. Second, the success of the PCT route is leading to the harmonizing of drafting styles worldwide on the US model. This paper therefore challenges the commonly accepted idea that more claims reflect a broader scope of protection by showing that the size of patents is partly due to institutional changes in the system. © 2009 Elsevier B.V. All rights reserved.