Out of court settlements are ubiquitous in patent litigation, due to the significant costs of pursuing a trial and uncertainty over its outcome. This is believed to encourage "frivolous" litigation, however the secretive nature of settlement agreements poses a challenge to evaluating the quality of cases filed and the cost they impose on innovators. I develop a dynamic model of litigation in which the defendant screens out plaintiffs through a series of sequential out-of-court settlement offers, exploiting heterogeneity in the likelihood of cases to be dismissed or successful. Employing a newly constructed dataset that combines granular information on all patent infringement cases filed in the US from 2007-2021 and data on the parties involved, I estimate my model. This allows me to retrieve (i) the distribution of the ex-ante probability of victory for plaintiffs, (ii) the unobserved distribution of settlement amounts and (iii) the relative bias of courts towards plaintiffs and defendants. I find that patent litigation costs over $48.8 billion a year to listed defendants, $24.7  billion of which are from settlement transfers. Furthermore, cases brought to court by patent assertion entities are smaller in size, lower in quality and more likely to settle for smaller amounts. I then consider two counterfactuals. First, I consider several fee-shifting rules, finding that conditional fee-shifting is effective in discouraging frivolous litigation, however it can induce costly delays before settlements. Then, I turn to forum shopping. I find that restricting plaintiffs' discretionality in the choice of venue would dramatically reduce the incentives to file low-quality cases, especially in the E.D. of Texas.

Patent Assertion Entities (PAEs) are often viewed as taxing innovative activity, We show how fee shifting in patent litigation can effectively deter their more frivolous assertions, increasing exposed firms’ R&D, innovation output, and startup success. Our identification relies on the U.S. Supreme Court’s 2014 ruling in Octane Fitness v. ICON Health & Fitness, which broadened courts’ discretion to award attorneys fees against exceptionally weak infringement claims. Using a quasi-regression discontinuity design comparing cases pending at Octane’s release with those filed and terminated before or after, we find that the decision increased defendants’ willingness to contest weak claims and prompted plaintiffs, especially PAEs, to file stronger ones. Pending cases saw more fee awards and lower settlement and plaintiff success rates; subsequent PAE cases involved stronger patents and higher success rates. A difference-in-differences analysis further shows that Octane boosted innovation: public firms that were particularly exposed to PAE assertions prior to Octane increased R&D and patenting in response, and private startup firms performed better in venture capital markets 

Understanding how many granted patents are actually valid, and why some examiners or technologies produce more invalid patents than others, is central to evaluating the patent system. Yet validity is revealed only for the small fraction of patents that are later challenged, and PTAB challenges are not random: they depend on patent quality, owner identity, enforcement behavior, and the private value of invalidation. This creates a severe selection problem for any attempt to use PTAB outcomes to evaluate patent examination.

This paper develops a structural framework that combines PTAB inter partes review data, USPTO examination records, patent ownership histories, and litigation data to recover the hidden error structure of patent examination. We model the examiner's grant decision and the petitioner's challenge decision within a unified latent-variable structure, exploiting heterogeneity in post-grant scrutiny across patent owners to identify examiner skill, grant thresholds, challenge selection, and latent patent validity. The same variation that makes PTAB outcomes selected therefore becomes the source of identification. The resulting estimates allow us to distinguish examination false positives from strategic selection into review, recover examiner and art-unit heterogeneity corrected for PTAB selection, and evaluate counterfactual reforms to examination time, art-unit guidelines, and the institutional weighting of Type I versus Type II errors.

We argue that a firm’s related technological capabilities could discourage rather than encourage entry into a nascent technology-based market. As such capabilities also have a potential application in other markets, firms consider the opportunity costs of foregoing entry elsewhere under resource constraints. We develop a simple model to determine the conditions under which this occurs and test the predictions of the model in a discrete hazard analysis of firms’ entry into the LED lighting market during its incubation period. Although core LED lighting capabilities are positively related to the entry hazard, related LED capabilities reduce the entry hazard. Entry is in particular discouraged if the alternative market exhibits greater growth potential. 

This project studies how competition among conglomerate incumbents for startup acquisitions shapes the direction of innovation. We develop a framework in which startups choose where to innovate in a technology space, anticipating acquisition bids from incumbents with different and potentially overlapping technological positions. Acquisition incentives depend not only on technological proximity, but also on how an acquisition affects competition and the balance of market leadership. We aim to characterize when the prospect of acquisition steers startups toward technologies that reinforce an incumbent’s existing position, challenge its leadership, or expand into previously unexplored areas. The analysis provides a framework for assessing the dynamic and antitrust implications of startup acquisitions by conglomerate firms, including acquisitions between firms that are not direct product-market competitors.