Can Modern Nuclear Hamiltonians Tolerate a Bound Tetraneutron?

I show that it does not seem possible to change modern nuclear Hamiltonians to bind a tetraneutron without destroying many other successful predictions of those Hamiltonians. This means that, should a recent experimental claim of a bound tetraneutron be confirmed, our understanding of nuclear forces will have to be significantly changed. I also point out some errors in previous theoretical studies of this problem.Comment: 4 pages, 4 figures Revision corrects a pronou

Exclusionary Conduct, Effect on Consumers, and the Flawed Profit-Sacrifice Standard

The central thesis of this article is that the use of the profit-sacrifice test as the sole liability standard for exclusionary conduct, or as a required prong of a multi-pronged liability standard is fundamentally flawed. The profit-sacrifice test may be useful, for example, as one type of evidence of anticompetitive purpose. In unilateral refusal to deal cases, it can be useful in determining the non-exclusionary benchmark. However, the test is not generally a reliable indicator of the impact of allegedly exclusionary conduct on consumer welfare - the primary focus of the antitrust laws. The profit-sacrifice test also is prone to several significant pitfalls and often would be complex and subjective to implement in practice. As a result, relying on the profit-sacrifice test as the legal standard would lead to significant legal errors

The Evolution and Vitality of Merger Presumptions: A Decision-Theoretic Approach

This article reviews the formulation and evolution of the Philadelphia National Bank anticompetitive presumption through the lens of decision theory and Bayes Law. It explains how the economic theory, empirical evidence and experience are used to determine a presumption and how that presumption interacts with the reliability of relevant evidence to rationally set the appropriate burden of production and burden of persuasion to rebut the presumption. The article applies this reasoning to merger presumptions. It also sketches out a number of non-market share structural factors that might be used to supplement or replace the current legal and enforcement presumptions for mergers. It also discusses the potential for conflicting presumptions and how such conflicts might best be resolved

Anticompetitive Overbuying by Power Buyers

Two types of single-firm overbuying are analyzed in this article. Predatory overbuying consists of overbuying inputs as a predatory strategy to cause buyer-side competitors in the input market to exit from the market or permanently shrink their capacity in order to gain monopsony power in the input market. Raising Rivals\u27 Costs (RRC) overbuying consists of overbuying inputs as an exclusionary strategy to raise rivals\u27 input costs and thereby gain market power in the output market. In most cases, the additional input purchases are used to produce output. However, in unusual cases a firm may engage in naked overbuying, that is, purchasing an input solely to deny it to rivals and then simply discarding the input

The First Principles Approach to Antitrust, Kodak, and Antitrust at the Millenium

In this essay, I reflect on an important contribution to the development of antitrust reasoning and law that arises out of the Supreme Court\u27s decision in Eastman Kodak Co. v. Technical Services, Inc. In particular, I discuss the decision\u27s relationship to what I have termed the first principles approach to market power and antitrust. In my view, one reason that Kodak is important is that it does not take a wooden approach in its economic reasoning. Instead, the opinion nimbly applies the basic principles of competitive analysis to a difficult dynamic context. This enables the majority to avoid rigid adherence to a single brand of economic orthodoxy, a strength demonstrated by the opinion\u27s evaluations of market definition and market power. This willingness to adapt to the continuing advances of economic analysis arising from new market conditions and new intellectual insights suggests that antitrust law is less likely to become an anachronism that will be superceded by some other form of governmental oversight

An Enquiry Meet for the Case: Decision Theory, Presumptions, and Evidentiary Burdens in Formulating Antitrust Legal Standards

Presumptions have an important role in antitrust jurisprudence. This article suggests that a careful formulation of the relevant presumptions and associated evidentiary rebuttal burdens can provide the “enquiry meet for the case” across a large array of narrow categories of conduct confronted in antitrust to create a type of “meta” rule of reason. The article begins this project by using decision theory to analyze the types and properties of antitrust presumptions and evidentiary rebuttal burdens and the relationship between them. Depending on the category of conduct and market structure conditions, antitrust presumptions lie along a continuum from conclusive (irrebuttable) anticompetitive, to rebuttable anticompetitive, to competitively neutral, and on to rebuttable procompetitive and conclusive (irrebuttable) procompetitive presumptions. A key source of these presumptions is the likely competitive effects inferred from market conditions. Other sources are policy-based -- deterrence policy concerns and overarching policies involving the goals and premises of antitrust jurisprudence. Rebuttal evidence can either undermine the facts on which the presumptions are based or can provide other evidence to offset the competitive effects likely implied by the presumption. The evidentiary burden to rebut a presumption depends on the strength of the presumption and the availability and reliability of further case-specific evidence. These twin determinants can be combined and understood through the lens of Bayesian decision theory to explain how “the quality of proof required should vary with the circumstances.” The stronger the presumption and less reliable the case-specific evidence in signaling whether the conduct is anticompetitive versus procompetitive, the more difficult it will be for the disfavored party to satisfy the evidentiary burden to rebut the presumption. The evidentiary rebuttal burden generally is a burden of production, but also can involve the burden of persuasion, as with the original Philadelphia National Bank structural presumption, or typical procompetitive presumptions. If a presumption is rebutted with sufficient offsetting evidence to avoid an initial judgment, the presumption generally continues to carry some weakened weight in the post-rebuttal phase of the decision process. That is, a thumb remains on the scale. However, if the presumption is undermined, it is discredited and it carries no weight in the post-rebuttal decision process. The article uses this methodology to analyze various antitrust presumptions. It also analyzes the, burden-shifting rule of reason and suggests that the elements should not be rigidly sequenced in the decision process. The article also begins the project of reviewing, revising and refining existing antitrust presumptions with proposed revisions and refinements in a number of areas. The article invites other commentators to join the project by criticizing these proposals and suggesting others. These presumptions then could be applied by appellate courts and relied upon by lower court, litigants and business planners

Analyzing Vertical Mergers to Avoid False Negatives: Three Recent Case Studies

This article analyzes three recent vertical mergers: a private antitrust case attacking the consummated merger of Jeld-Wen and Craftmaster Manufacturing Inc. (“CMI”) that was cleared by the DOJ in 2012 but subsequently litigated and won by the plaintiff, Steves & Sons in 2018; and two recent vertical merger matters investigated and cleared (with limited remedies) by 3-2 votes by the Federal Trade Commission in early 2019 -- Staples/Essendant and Fresenius/NxStage. There are some factual parallels among these three matters that make it interesting to analyze them together. First, the DOJ’s decision to clear Jeld-Wen/CMI merger appears to be a clear false negative, and the two dissenting Commissioner suggest that the recent FTC decisions similarly are false negatives. Second, the DOJ and possibly the FTC in Staples/Essendant may have overlooked the “Frankenstein Monster” scenario of input foreclosure. Third, both the DOJ and the FTC in Fresenius/NxStage also apparently relied on the absence of complaints in making their clearance decisions. The analysis of these mergers also suggests several policy implications involving the need to analyze the full range of anticompetitive concerns, the potential for merger retrospectives by independent (as opposed to staff) researchers, the height of the evidentiary burden on the agencies to show competitive harm in light of their limited budgets, and the need for greater transparency in Commission statements, as well as the potential errors in relying on a lack of complaints

The AT&T/Time Warner Merger: How Judge Leon Garbled Professor Nash

The US District Court in the AT&T/Time Warner vertical merger case has issued its opinion permitting the merger. At of this writing in August 2018, the Department of Justice (DOJ) has appealed to the DC Circuit and filed its brief, as have several Amici. I was disappointed that the DOJ was unable to prove its case to the satisfaction of Judge Leon, the trial judge. Notwithstanding the court’s confidence that the merger is procompetitive, I remain concerned that it will have anti- competitive effects, both on its own and following the subsequent vertical mergers in the TV industry, which this decision may will encourage and permit. This commentary offers some reflections on Judge Leon’s opinion, not the future of the industry. It sets out a critical analysis of the court’s sceptical treatment of the Nash bargaining theory that formed the basis of the DOJ’s complaint and the economic errors he made. Judge Leon also rejected the empirical inputs that were used by DOJ’s expert economist, Professor Carl Shapiro, in his quantitative analysis, though this article will not analyse these issues. It will, however, raise questions about whether Judge Leon’s economic errors in analysing the bargaining model might have affected his interpretation of the evidence. The commentary also will offer some critical thoughts about the DOJ’s treatment of efficiencies from the elimination of double marginalization

The 2020 Vertical Merger Guidelines: A Suggested Revision (March 26, 2020)

The FTC and DOJ requested comments on their draft Vertical Merger Guidelines in January 2020. This article is a complete alternative set of suggested Vertical Merger Guidelines that reflects and supplements the approach explained in the comments submitted by the author along with Jonathan. Baker, Nancy Rose and Fiona Scott Morton, as well as their other comments, and might be read in conjunction with those comments. This suggested revision of the Agencies’ draft expands the list of potential competition harms and provides illustrative examples. It expands and unifies the discussion and treatment of potential competitive benefits. It deletes the quasi-safe harbor and suggests the circumstances under which competitive harms raise lessened concerns on the one hand and heightened concerns on the other

Designing relational pedagogies with jam2jamXO

This paper examines the affordances of the philosophy and practice of open source and the application of it in developing music education software. In particular I will examine the parallels inherent in the ‘openness’ of pragmatist philosophy in education (Dewey 1916, 1989) such as group or collaborative learning, discovery learning (Bruner 1966) and learning through creative activity with computers (Papert 1980, 1994). Primarily I am interested in ‘relational pedagogies’ (Ruthmann and Dillon In Press) which is in a real sense about the ethics of the transaction between student and teacher in an ecology where technology plays a more significant role. In these contexts relational pedagogies refers to how the music teacher manages their relationships with students and evaluates the affordances of open source technology in that process. It is concerned directly with how the relationship between student and teacher is affected by the technological tools, as is the capacity for music making and learning. In particular technologies that have agency present the opportunity for a partnership between user and technology that enhances the capacity for expressive music making, productive social interaction and learning. In this instance technologies with agency are defined as ones that enhance the capacity to be expressive and perform tasks with virtuosity and complexity where the technology translates simple commands and gestures into complex outcomes. The technology enacts a partnership with the user that becomes both a cognitive and performative amplifier. Specifically we have used this term to describe interactions with generative technologies that use procedural invention as a creative technique to produce music and visual media