Patent analyses in the changed legal regime of the US Patent Law since 2001

In 2001, a new ruling for the publication of patent applications at the United States Patent and Trademark Office came into effect. Since then, all applications which are also filed with foreign offices have to be published 18 months after the application date, in analogy to the ruling in Europe and Japan. This new regime replaces the former system where only granted patents were published. With about 70% of all applications the share of pre-grant publications of applications of US origin is quite high, allowing new types of statistical analysis. In particular, the investigations of time series based on priority years instead of grant years can thus be performed much more topically. On the one hand, a larger dataset for applications of US origin is available; on the other hand, the sample of applications from Asian countries is generally much larger at the US Patent Office than at the European Patent Office. Despite these new opportunities, searches at low levels of aggregation by codes of the International Patent Classification still have to be handled with care.