A brief history of space and time: The scope-year index as a patent value indicator based on families and renewals

The renewal of patents and their geographical scope for protection constitute two essential dimensions in a patent's life, and probably the most frequently used patent value indicators. The intertwining of these dimensions (the geographical scope of protection may vary over time) makes their analysis complex, as any measure along one dimension requires an arbitrary choice on the second. This paper proposes a new indicator of patent value, the scope-year index, combining the two dimensions. The index is computed for patents filed at the EPO from 1980 to 1996 and validated in its member states. It shows that the average value of patent filings has increased in the early eighties but has constantly decreased from the mid-eighties until the mid nineties, despite the institutional expansion of the EPO. This result sheds a new and worrying light on the worldwide boom in patent filings.