– Antitrust Laws: The legal framework aimed at ensuring that competition governs markets by sanctioning conduct that distorts market competition 

– Chicago School Position: A framework for analyzing competition and antitrust, developed in the 1970s and 1980s at the University of Chicago Law School. The position centers around the use of economic analysis to inform the goals of antitrust law.  

– Clayton Antitrust Act: Enacted in 1914, this supplemented the Sherman Act by outlawing additional anticompetitive practices, such as anticompetitive mergers and predatory and discriminatory pricing. The Clayton Act remains a bedrock of U.S. antitrust law today.

– Consumer Welfare Standard: The objective, economics-based standard, that posits that the maximization of benefits to consumers is the goal of the antitrust law. Consumer welfare has held up as the standard precisely because it is clear and pro-consumer.

– Data Portability: The ability for users to transfer data, like photos, from one company to another. 

– Essential Facilities Doctrine: An antitrust legal construct that considers whether access to a facility or infrastructure is necessary for companies to compete in a relevant market. The U.S. Supreme Court has not explicitly recognized the application of this doctrine in the US antitrust system.

– Killer Acquisition: The allegation that large tech companies seek to stifle future competition by acquiring smaller, up-and-coming companies.

– Kill Zone: The allegation that an overly concentrated technology market stifles venture capital funding and growth ability among startups and small businesses. The kill zone holds that leading tech services replicate the products of their smaller competitors, and leverage market power to stifle competition . 

– Louis Brandeis: Served as an associate justice of the U.S. Supreme Court from 1916 to 1939, where he pushed for stringent regulation of business competitors. Brandeis associated firm size — not the number of competitors in a sector — with market power and denounced the efficiencies and consumer benefits that larger companies can provide.

– Market:

– Market Concentration: Economic exercise that relates to the number of firms competing in a given industry and their relative market shares. Market concentration does not necessarily indicate lack of competition.

– Market Definition: Economic exercise performed when enforcing antitrust norms to determine the limits of the market to which the analysis that determines whether a competition restraint has occurred will be applied. 

– Market Power (distinct from Market Share): The ability of a firm to profitably raise the market price of a good or service over marginal cost.

– Multi-Sided Market: Often called a “platform,” a multi-sided market helps bridge two or more groups of distinct but interdependent customers together. Examples of multi-sided markets include network television that connect viewers and advertisers, or web auction sites that connect buyers and sellers and goods.

– Merger:

– Horizontal Merger: A merger between companies competing in the same market of products or services.  

– Procompetitive Merger: A merger between two companies which ultimately expands output and benefits consumers.

– Vertical Merger: A merger between two companies that operate in different markets or sectors.

– Monopoly: The allegation of single-company domination of a market or product. Monopolies do not inherently require antitrust intervention.

– Conglomerate Merger: A merger between two companies that not only compete in the same market of products and/or services, but also operate in different markets and sectors without competing against each other.

– Multihoming: Consumer “switching” between platforms with similar or comparable uses, rather than choosing only one platform to use, e.g., consumers subscribing to multiple streaming services for entertainment.

– Nascent Competitor: A smaller, up-and-coming company that challenges the legacy competitors in the space.

– Neo-Brandeisian / New Brandeis School / Hipster Antitrust: A framework of antitrust analysis that focuses on company size, rather than the benefit of its products and services for consumers. The framework focuses on subjective enforcement and protecting businesses.

– Network Effects: The concept that as a product or service gains users, the usefulness of that product increases, e.g., the experience of using a social network increases as more friends and family members use that network. 

– Predatory Pricing: The belief that if large companies offer prices below cost, they will outsell their competitors, ultimately driving them out of the market. 

– Public Utility Regulation: A non-market-based approach to the provision of certain essential public services.  It is characterized not by marketplace competition, but rather rate regulation of a (usually) sole-source provider — either publicly or privately owned — conditioned on service obligations.  Because the model generally contemplates only one provider, antitrust law generally does not apply to rate-regulated activities, because there is no meaningful “market.”

– Robert Bork / The Antitrust Paradox: A legal scholar and former solicitor general of the United States, Bork wrote The Antitrust Paradox in 1978, arguing for a consumer welfare-based antitrust framework that remains the bedrock of objective antitrust analysis today. He is credited with ushering in modern antitrust theory that has led to unprecedented growth and innovation. 

– Self-Preferencing: The concept that platforms elevate their own products and services compared to those provided by third parties. 

– Sherman Antitrust Act: Enacted in 1890, the Sherman Antitrust Act marked the origination of U.S. antitrust law. The act established an initial purpose of consumer protection while prohibiting anti competitive agreements.

– The Curse of Bigness / Tim Wu: – An attorney, Wu wrote The Curse of Bigness: Antitrust in the New Gilded Age in 2018. The book largely criticizes leading tech services and alleges a lack of competition in the sector, receiving widespread scrutiny from antitrust experts. 

– United States v. Microsoft (1998): – A landmark 2001 decision from the DC District Court that provided for the balanced framework to guide antitrust enforcement, particularly in innovative and dynamic markets. The decision applied existing antitrust law, demonstrating its enduring potency to address modern technology markets.