Methodological challenges for creating accurate patent indicators

The chapter deals with new methodological issues of retrieval for patent indicators linked to the change of the patent system in the last 20 years and the new ways to access patent data. In particular, it describes international flows of patent applications between the US, Europe, and Southeast Asia, and illustrates methods for an appropriate cross-country comparison. A central topic of this chapter is the implications of the frequently used Patent Cooperation Treaty route of patent applications on the conception of search strategies and the interpretation of search results. Furthermore, the possibilities of search with the new international Cooperative Patent Classification are explained. In addition, the patenting activities of very large companies and patent value are discussed.