Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Patents are typically characterized as assets of great values. Nevertheless, there are many patents that are actually never used. In this article, we claim that there is a relationship between the duration of patents and the characteristics of the underlying invention. From the viewpoint of Public Research Institutes, the duration of patents may be a proxy of probability of technology transfer because the long lived patents have higher value and more chances to be transferred. We characterize the patents along different dimensions captured by the renewal and application data, i.e. collaboration, scope, competitiveness and attractiveness. The results of hazard rate duration analysis tell us that long lived patents are characterized by being more focused, having more competitiveness, and being more collaborative. In addition, it is analysed that patents in chemical industry expire faster than those in electrical/electronic industry. Though this fact is against the general intuition, it may be reasonable from a viewpoint of technology transfer.