We address a longstanding question about the causes of creative destruction. Dominant incumbent firms, long successful in an existing technology, are often much less successful in new technological eras. This is puzzling, since a cursory analysis would suggest that incumbent firms have the...

Recent empirical studies suggest a need for a flexible patent regime responding to industry characteristics. In practice, sector-specific modifications of patent strength already exist but lack theoretical foundation. This paper intends to make up for this neglect by scrutinizing in what...