These Economics W.I.R.E.D. activities recommend web links that relate to key concepts of each chapter of the textbook. For each link, there are instructions to guide you to specific information, followed by several discussion questions or exercises.

Key Concepts: Antitrust Policy, Regulating Natural Monopolies, To Regulate or Not to Regulate

U.S. Census—Herfindahl Index

Review the various industries listed on the page by SIC (Standard Industry Classification) code. Scroll down to "Subject Series" and click on "Concentration Ratios in Manufacturing." Review the "Table 3" Herfindahl index information for referenced SIC (Standard Industry Classification) codes.

• Identify the highest HHI measure Industry Group. Explain why the Justice Department may scrutinize merger activities in this industry group.
• Is there a relationship between "number of companies" and its corresponding "HHI" measure? Why?
• Review the antitrust Mission Statement of the Federal Trade Commission (FTC). Explain why a high HHI measure does not automatically warrant the FTC to pursue antitrust actions.