Examination — the process of reviewing a patent application and deciding whether to grant the requested patent — improves patent quality in two ways. It acts as a substantive screen, filtering out meritless applications and improving meritorious ones. It also acts as a costly screen, discouraging applicants from seeking low-value patents. Yet despite these dual roles, the patent system has a substantial quality problem: it is both too easy to get a patent (because examiners grant invalid patents that should be filtered out by a substantive screen) and too cheap to do so (because examiners grant low-value nuisance patents that should be filtered out by a costly screen). This Article argues that these flaws in patent screening are both worse and better than has been recognized. The flaws are worse because they are not static, but dynamic, interacting to reinforce each other. This interaction leads to a vicious cycle of more and more patents that should never have been granted. When patents are too easily obtained, that undermines the costly screen, because even a plainly invalid patent has a nuisance value greater than its cost. And when patents are too cheaply obtained, that undermines the substantive screen, because there will be more patent applications, and the examination system cannot scale indefinitely without sacrificing accuracy. The result is a cycle of more and more applications, being screened less and less accurately, to give more and more low-quality patents. And although it is hard to test directly if the quality of patent examination is falling, there is evidence suggesting that this cycle is affecting the patent system. At the same time, these flaws are not as bad as they seem because this cycle may be surprisingly easy to solve. The cycle gives policymakers substantial flexibility in designing patent reforms, because the effect of a reform on one piece of the cycle will propagate to the rest of the cycle. Reformers can concentrate on the easiest places to make reforms (like the litigation system) instead of trying to do the impossible (like eliminating examination errors). Such reforms would not only have local effects, but could help make the entire patent system work better.
