Vanderbilt Law Review


Tun-Jen Chiang

First Page



The discussion of search in patent law always focuses on one particular model of search: producers of commercial products are supposed to identify the patents that their products might infringe and then negotiate a license from the owners of those patents. This one-sided view of search responsibility is most evident in doctrine. As a doctrinal matter, patent law imposes an absolute duty on the producer of a commercial product to find all relevant patents and obtain licenses from each of the owners before commencing manufacture. Failure to meet this duty is punished by liability for infringement, where ignorance of the patent is no excuse.' The one-sided view of search, however, is treated as far more than simply a matter of doctrine. Numerous prominent commentators have sharply criticized the current doctrine. In what has become known as the "patent thicket" literature, these critics argue that producers face excessively high search costs because a commercial product is often covered by thousands of overlapping patents and finding every last patent is impossible. The irony of this critique is that these critics still adopt a one-sided view of search, in that they only ever examine the costs and difficulties of producers finding patentees. Once the critics conclude that this one particular type of search is too expensive, they immediately conclude that all searching is impossible. The point of this Article is that search is reciprocal. In designing a patent system, we can require producers to look for patentees, or we can require patentees to look for producers. Either will achieve the goal of an ex ante licensing negotiation that patent search is designed to facilitate. There is no intrinsic reason that patent law must prefer to place the search obligation on one side or the other. The choice is a matter of system design.