Technology entry in the presence of patent thickets
研究了专利丛林如何影响企业首次申请专利的进入决策，利用英国数据发现专利丛林会减少技术领域的首次专利申请，且这种效应独立于技术复杂性和机会。
Abstract We analyse how patent thickets affect entry into patenting. A model of entry into patenting that allows for variation in technological opportunity, technological complexity and the extent of patent thickets is developed and analysed. Using UK data we then show that patent thickets are associated with a reduction of first time patenting in a technology controlling for the level of technological complexity and opportunity. Technologies characterized by more technological complexity and opportunity attract more entry into patenting. Our evidence indicates that patent thickets raise entry costs, which leads to less entry into technologies regardless of a firm’s size.