Many patent assertion entities (PAEs) hide behind multiple unknown subsidiaries or shell companies with obscure ownership. Meanwhile, the United States Patent and Trademark Office (USPTO), like many other patent offices, does not impose a strict time period for recording the change of ownership of a patent, allowing the holder to gain an advantage by controlling the timing of its ownership disclosure. In this paper, we study to which extent PAEs delay the recording of the U.S. patent reassignments of patents that they will subsequently use in infringement patent lawsuits. On average, PAEs notify the change of ownership more quickly than producing firms, but this is not the case for the patents that they will litigate relatively far in time. In particular, the correlation between the recording lag of the patent transaction and the litigation spell is higher when the patent acquirer is a PAE (than when it is a producing firm) or when the acquirer will litigate the patent in the Eastern District of Texas, famously home to opportunistic litigations. Finally, we find that transactions involving unknown subsidiaries of PAEs are recorded at the USPTO significantly later than those involving PAE parent companies or their known subsidiaries.

中文翻译：

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专利声明实体和专利所有权透明度：美国专利商标局专利交易的战略记录

许多专利主张实体 (PAE) 隐藏在多个未知的子公司或空壳公司的背后，其所有权不明确。同时，美国专利商标局 (USPTO) 与许多其他专利局一样，没有对专利所有权变更的记录规定严格的时间期限，允许持有人通过控制其所有权的时间来获得优势披露。在本文中，我们研究了 PAE 在多大程度上延迟了他们随后将在专利侵权诉讼中使用的美国专利重新转让的记录。平均而言，PAEs 通知所有权变更的速度比生产企业更快，但对于他们诉讼时间相对较远的专利而言，情况并非如此。特别是，记录滞后之间的相关性当专利收购方是 PAE（比起生产公司）或收购方将在德克萨斯州东区对专利提起诉讼时，专利交易和诉讼的风险会更高，这里是著名的机会主义诉讼的发源地。最后，我们发现涉及 PAE 未知子公司的交易在美国专利商标局记录的时间明显晚于涉及 PAE 母公司或其已知子公司的交易。