Lesson Plan

• Define market dominance and list its main sources.
• Calculate the Concentration Ratio (CR) and Herfindahl‑Hirschman Index (HHI) and interpret the results.
• Analyse the welfare implications of dominant firms (allocative, productive and dynamic inefficiencies).
• Evaluate appropriate policy responses such as antitrust law, regulation of natural monopolies and merger control.

• Projector and screen
• PowerPoint slides on market dominance
• Printed worksheets with market‑share data
• Calculators
• Handout of CR and HHI formulas
• Whiteboard and markers

Begin with a quick poll: “Which companies do you think dominate their markets today?” Connect this to the previous lesson on competition vs monopoly, and state that by the end of class students will be able to identify dominance, measure it, and assess its effects.

1. Do‑now (5'): Quick quiz on perfect competition vs monopoly concepts.
2. Mini‑lecture (10'): Definition of market dominance, sources, and introduction to CR & HHI.
3. Guided practice (12'): In pairs, calculate CR and HHI using the worksheet data; discuss interpretation thresholds.
4. Concept check (5'): Whole‑class poll on HHI categories (unconcentrated, moderate, high).
5. Welfare analysis activity (10'): Label a monopoly diagram showing price, MC, MR and dead‑weight loss.
6. Policy debate (8'): Small groups evaluate one policy tool (e.g., antitrust law) for a case study and present a brief argument.
7. Summary & exit ticket (5'): Students write one key takeaway and one lingering question; collect.

Recap the definition, measurement, and welfare effects of market dominance, highlighting how policy tools aim to restore efficiency. Collect exit tickets as a retrieval check and assign homework: find a real‑world market, calculate its HHI, and suggest an appropriate policy response.