Effects of co-patenting across national boundaries on patent quality. An exploration in pharmaceuticals

This paper explores three novel research questions. First, is an increase in the number of countries involved in ownership of a co-patent an effective way to enhance patent quality? Second, if the objective is to raise patent quality, which are the right countries to collaborate with? And third, does cooperation with partners located in a tax haven affect patent quality? The empirical methodology relies on forward citations as an indicator of quality, and patent co-ownership as a measure of international collaboration. We estimated several count models with a sample of 143,479 pharmaceutical patents (patent families). Our econometric findings show that, first, the average effect of international collaboration is a 4.9% increase in patent quality compared with those patents for which the assignees come from a single country (once we controlled for patent characteristics). When the number of countries in which the assignees are based increases, the effect of this wider collaboration on patent quality is also greater, though only for up to a maximum of five countries. Second, to produce patents of better quality, the most suitable countries with which to collaborate were found to be the United States, Switzerland, Japan, Germany and the United Kingdom. Finally, collaboration with firms located in a country categorized as a tax haven does not have any significant impact on patent quality.