Sean Sullivan

Sean Sullivan
University of Iowa | UI · College of Law

PhD JD

About

25
Publications
4,156
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
81
Citations
Citations since 2017
14 Research Items
64 Citations
2017201820192020202120222023051015
2017201820192020202120222023051015
2017201820192020202120222023051015
2017201820192020202120222023051015
Introduction
My research merges traditional legal analysis with economics and statistics. I am particularly interested in using game theory, probability theory, and experimental economics as tools of doctrinal analysis. I write on topics in Evidence Law, Antitrust Law, and Law and Economics.

Publications

Publications (25)
Article
Full-text available
Antitrust analysis is famously complex, fact intensive, and time consuming. But should we aspire for it to be otherwise? I offer two cautionary conjectures in opposition to the search for simpler rules. First, I conjecture that efforts to convert vague antitrust standards into clear rules will rarely succeed without abandoning the underlying standa...
Article
Full-text available
Roughly a year into control of the federal antitrust agencies, President Biden’s antitrust team is turning its attention to policies and enforcement practices. They seem poised to start, as antitrust so often does, with market definition. This is an appropriate target for review but also perilous territory for the administration. Even slight misste...
Article
Full-text available
Entry defenses and potential competition doctrine have much in common. Both draw from predictions about future entry. Both demand difficult assessments of entry barriers and incentives. And both suffer from confused thinking today. This Article offers a clarifying perspective. Rather than focus on matters of litigation posture (who wins or loses if...
Preprint
Full-text available
Surging interest in antitrust enforcement is exposing, once again, the difficulty of defining relevant markets. Past decades have witnessed the invention of many tests for defining markets, but little progress has been made, or even attempted, at reconciling these different tests. Modern market definition has thus become a confused agglomeration of...
Preprint
Full-text available
Monopolization, in the United States, and abuse of dominance, in the European Union, embody different philosophies about how best to police single firm conduct in competition law. Surprisingly, their disagreement ends at market definition. Both doctrines define relevant markets by similar processes and use relevant markets for similar purposes. In...
Article
Full-text available
Surging interest in antitrust enforcement is exposing, once again, the difficulty of defining relevant markets. Past decades have witnessed the invention of many tests for defining markets, but little progress has been made, or even attempted, at reconciling these different tests. Modern market definition has thus become a confused agglomeration of...
Article
Full-text available
Mounting public concern with the exercise of market power in concentrated markets demands a response. While modern antitrust emphasizes the prevention of market power over reaction to its exercise, it does contain one indirect but potentially important tool for addressing problems with already existing concentration and market power: the often-over...
Article
Full-text available
Advocates of traditional antitrust are increasingly called upon to the defend the existing framework. In doing so they face a challenge: the traditional framework is actually quite difficult to explain. The problem is not that modern antitrust involves a lot of advanced economics—though that is also true. The problem is that foundational antitrust...
Article
A paradigm shift is underway in scholarship on legal fact-finding. Recent work points clearly and consistently in the direction that persuasion is the product of purely comparative assessments of factual propositions. This paper comments on the philosophical roots of this shift to a comparative paradigm. It also highlights two serious challenges fo...
Article
Full-text available
Are racial stereotypes a proper basis for legal fact-finding? What about gender stereotypes, sincerely believed by the fact-finder, and informed by the fact-finder’s life experience? What about population averages: if people of a certain gender, education level, and past criminal history exhibit a statistically greater incidence of violent behavior...
Article
Full-text available
Proving a violation of law is costly. Because of the cost, minor violations of law often go unproven and thus unpunished. To illustrate, almost everyone drives a little faster than the speed limit without getting a ticket. The failure to enforce the law against minor infractions is justifiable from a cost-benefit perspective. The cost of proving a...
Article
Full-text available
This paper uses the framework of aggregation and separation that Lee Fennell develops in Slices and Lumps to discuss two fundamental questions of antitrust policy. First, how far does the lumpiness of trading partners dictate the limits of antitrust policy? Second, what does antitrust miss under the common practice of lumping price, consumer welfar...
Article
Full-text available
Of all constitutional puzzles, the nondelegation principle is one of the most perplexing. How can a constitutional limitation on Congress’s ability to delegate legislative power be reconciled with the huge body of regulatory law that now governs so much of society? Why has the Court remained faithful to its intelligible principle test, validating e...
Article
Full-text available
Despite the voluminous commentary that the topic has attracted in recent years, much confusion still surrounds the proper definition of antitrust markets. This paper seeks to clarify market definition, partly by explaining what should not factor into the exercise. Specifically, we identify and describe three common errors in how courts and advocate...
Article
The US legal system encourages civil litigants to quickly settle their disputes, yet lengthy and expensive delays often precede private settlements. The causes of these delays are uncertain. This paper describes an economic experiment designed to test one popular hypothesis: that asymmetric information might be a contributing cause of observed sett...
Article
Full-text available
The “structural presumption” is a proposition in antitrust law standing for the typical illegality of mergers that would combine rival firms with large shares of the same market. Courts and commentators are rarely precise in their use of the word “presumption,” and there is foundational confusion about what kind of presumption this proposition actu...
Article
The US legal system encourages civil litigants to quickly settle their disputes, yet lengthy and expensive delays often precede private settlements. The causes of these delays are uncertain. This paper describes an economic experiment designed to test one popular hypothesis: that asymmetric information might be a contributing cause of observed sett...
Article
Full-text available
The doctrine of chances remains a divisive rule in the law of evidence. Proponents of the doctrine argue that evidence of multiple unlikely events of a similar nature supports an objective, statistical inference of lack of accident or random chance on a particular occasion. Opponents argue that admissibility is improper because the underlying infer...
Article
The thesis of this paper is that Baker Hughes burden shifting is bad law, a doctrinal heresy undeserving of its current influence and overdue to be overturned. As a positive matter, Baker Hughes burden shifting evinces a dubious pedigree, and is at any rate an unpersuasive interpretation of law. The burden-shifting structure is unsuited to the avai...
Article
Full-text available
In many western countries, rising public concern for the welfare of agricultural animals is reflected in the adoption of direct regulatory standards. The United States has taken a different path, preferring a “market regulation” approach whereby consumers express their preference for agricultural animal welfare through their consumption habits, inc...
Article
Full-text available
Laboratory experiments are used to investigate alternative solutions to the allocation problem of a common-pool resource with unidirectional flow. Focus is on the comparative economic efficiency of nonbinding communications, bilateral "Coasian" bargaining, allocation by auction, and allocation by exogenous usage fee. All solutions improve allocativ...
Article
In the United States legal system, tort disputes often exhibit protracted delay between injury and settlement. That is, parties to a dispute tend to agree on settlement conditions only after engaging in lengthy legal sparring and negotiation. Resources spent on settlement negotiation are large and economically inefficient. This research contributes...
Chapter
While accurate data are critical in understanding crime and assessing criminal justice policy, data on crime and illicit activities are invariably measured with error. In this chapter, we illustrate and evaluate several examples of measurement error in criminal justice data. Errors are evidently pervasive, systematic, frequently related to behavior...
Article
In the United States legal system, tort disputes often exhibit protracted delay between injury and settlement. That is, parties to a dispute tend to agree on settlement conditions only after engaging in lengthy legal sparring and negotiation. Resources committed to settlement negotiation are large and economically inefficient. Even small reductions...

Network

Cited By

Projects

Projects (2)
Project
Research on the manner in which fact-finders draw inferences about uncertain facts from evidence.
Project
Research revisiting basic antitrust concepts and doctrine from an economic perspective.