Abstract
Breakthrough innovations – commonly defined by innovations with patents surpassing a critical threshold of forward citations – generate benefits for innovators, businesses, and society. Analyzing more than five million patents and citations from 1976 to 2017, this paper adds to the existing literature by examining whether the radicalness of a patented good – that is, the more technology classes cited as contributing prior arts not identified in the patent’s own technology identity – impacts the likelihood an innovation is a breakthrough. In essence, the paper tests the common belief that it is beneficial to “think outside the box” when innovating. The results show that increased radicalness increases the likelihood of a breakthrough up to a certain threshold, after which increased radicalness decreases the likelihood of a breakthrough. Additionally, established innovators and university ownership of a patent each extend the range for which increased radicalness increases the probability of a breakthrough, while joint patent ownership decreases the range.