Antitrust Policy: History and Application

Active learning works for antitrust policy because the subject requires students to apply abstract legal and economic concepts to real-world scenarios. By engaging with cases, simulations, and debates, students practice defining markets, calculating competition metrics, and weighing policy trade-offs, which builds deeper understanding than passive reading alone.

• 12th Grade
• Economics
• 4 activities
• 30 min–50 min

Learning Objectives

1. Explain the historical motivations and key provisions of the Sherman Antitrust Act and the Clayton Act.
2. Analyze the process by which government agencies define relevant product and geographic markets during merger reviews.
3. Calculate the Herfindahl-Hirschman Index (HHI) for a given market structure and interpret its implications for competition.
4. Critique the application of traditional antitrust frameworks to digital markets, considering network effects and zero-price services.
5. Evaluate the arguments for and against breaking up large technology companies using economic principles.

Mock Trial

⏱ 50 min·Small Groups

Mock Merger Review

Groups receive financial and market share data for a hypothetical merger in a specific industry, calculate the pre- and post-merger HHI, and present a recommendation to the class acting as the DOJ: approve, block, or approve with conditions. Groups must justify their market definition and HHI thresholds.

Prepare & details

Explain the historical context and purpose of antitrust laws.

Facilitation Tip: During the Mock Merger Review, give students a simplified HHI calculation template so they focus on market analysis rather than arithmetic errors.

Setup: Desks rearranged into courtroom layout

Materials: Role cards, Evidence packets, Verdict form for jury

• Analyze
• Evaluate
• Create
• Decision-Making
• Social Awareness

Case Study Analysis

⏱ 35 min·Pairs

Case Study Analysis: Standard Oil and Modern Tech Antitrust

Pairs compare the 1911 Standard Oil breakup with ongoing FTC and DOJ cases against major technology platforms, identifying parallels in legal theory and differences in how modern digital markets function. They write a brief memo explaining which elements of the Standard Oil analysis do and do not transfer to the tech context.

Prepare & details

Analyze how the government defines a market when reviewing mergers.

Setup: Groups at tables with case materials

Materials: Case study packet (3-5 pages), Analysis framework worksheet, Presentation template

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Formal Debate

⏱ 45 min·Small Groups

Formal Debate: Should the Government Break Up Large Tech Companies?

Teams prepare economic and legal arguments for and against structural remedies in technology markets, engaging with the consumer welfare standard that has governed antitrust since the 1970s. After the debate, the class identifies the key empirical disputes, does platform dominance harm consumers?, that would need to be resolved to reach a conclusion.

Prepare & details

Critique the arguments for and against breaking up large tech companies under antitrust.

Setup: Two teams facing each other, audience seating for the rest

Materials: Debate proposition card, Research brief for each side, Judging rubric for audience, Timer

• Analyze
• Evaluate
• Create
• Self-Management
• Decision-Making

Gallery Walk

⏱ 30 min·Small Groups

Gallery Walk: Landmark Antitrust Cases

Stations cover Standard Oil (1911), AT&T (1984), Microsoft (2001), and a recent platform case. Groups rotate and annotate each station with: the market failure alleged, the remedy applied, and one unresolved question about whether the outcome served consumers well.

Prepare & details

Explain the historical context and purpose of antitrust laws.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Teaching This Topic

Teachers should emphasize that antitrust law is not about punishing success but about preserving competitive processes. Avoid framing the topic as ‘big vs. small’ firms, as this oversimplifies the legal standards. Instead, use side-by-side case comparisons to show how courts weigh market power, intent, and consumer harm. Research suggests students grasp these nuances best when they grapple with conflicting interpretations of the same case.

What to Expect

Successful learning looks like students confidently distinguishing lawful competitive behavior from anticompetitive conduct, justifying their reasoning with economic evidence and historical precedents. They should also articulate how antitrust remedies are tailored to specific market harms, not just firm size.

Watch Out for These Misconceptions

Common Misconception

During the Mock Merger Review, watch for students assuming that any merger between large firms is automatically anticompetitive.

What to Teach Instead

During the Mock Merger Review, redirect students to the HHI thresholds and market definition steps, emphasizing that only mergers that substantially lessen competition violate the Clayton Act. Have them calculate pre- and post-merger HHI to anchor their analysis in data.

Common Misconception

During the Case Study: Standard Oil and Modern Tech Antitrust, watch for students conflating market dominance with illegal monopolization.

What to Teach Instead

During the Case Study: Standard Oil and Modern Tech Antitrust, ask students to compare Standard Oil’s exclusionary practices (e.g., rebates, predatory pricing) with modern tech firms’ competitive strategies. Use the case’s ‘rule of reason’ analysis to highlight that conduct, not size, determines liability.

Assessment Ideas

Discussion Prompt

After the Debate: Should the Government Break Up Large Tech Companies?, pose the question to the class and require students to support their arguments with concepts like market definition, HHI, and network effects, referencing specific examples of market power and competitive practices.

Quick Check

During the Mock Merger Review, provide students with a simplified smartphone OS merger scenario. Ask them to define the product and geographic markets, calculate the HHI before and after the merger, and state whether the merger raises antitrust concerns based on their calculations.

Exit Ticket

After the Gallery Walk: Landmark Antitrust Cases, ask students to write down one historical case and explain how it relates to the core purpose of antitrust laws. Then, have them identify one challenge in applying these laws to today's digital economy.

Extensions & Scaffolding

• Challenge early finishers to design a merger scenario that would likely raise antitrust concerns and justify their reasoning using HHI thresholds.
• For students who struggle, provide a partially completed case study template with key legal and economic terms filled in to guide their analysis.
• For extra time, have students research and present on a recent antitrust case, such as the FTC’s challenge to the Microsoft-Activision merger.

Key Vocabulary

Monopoly	A market structure characterized by a single seller, where one firm has exclusive control over a product or service and can significantly influence prices.
Relevant Market	The specific product or service and the geographic area within which competition is assessed for antitrust purposes, crucial for defining market share and concentration.
Herfindahl-Hirschman Index (HHI)	A measure of market concentration calculated by summing the squares of the market shares of all firms in an industry, used to assess potential anticompetitive effects of mergers.
Network Effects	A phenomenon where the value or utility a user derives from a good or service increases as the number of other users of the same good or service grows.
Merger	The combination of two or more companies into a single, larger corporation, which is subject to antitrust review to prevent undue market concentration.